WO2007012267A1

WO2007012267A1 - Methods for reducing fluid resistance and an apparatus for the same

Info

Publication number: WO2007012267A1
Application number: PCT/CN2006/001825
Authority: WO
Inventors: Lisong Zou
Original assignee: Lisong Zou
Priority date: 2005-07-29
Filing date: 2006-07-24
Publication date: 2007-02-01
Also published as: CN1730950A

Abstract

A method for reducing fluid resistance includes the step of: providing at least one level of moveable walls in turn on the object to be reduced resistance, said one level comprising no less than one layer wall. Said moveable walls run in certain relative speed so as to affect fluid flow. Accordingly, fluid running across the object surface may become stratified flow. On the other hand, said moveable walls is contacted with fluid and is functioned as a boundary face, so that the boundary face and the object surface could be separated. Moreover, said boundary face runs with fluid and the relative speed between them is lessened, without affecting the motion of the object. In addition, the present invention also disclosed an apparatus for reducing fluid resistance.

Description

Method and device for reducing fluid resistance

The present invention relates to a method and a typical apparatus for reducing fluid resistance (resistance including frictional resistance, cohesive resistance, and the like) and having a pushing function (pressurizing function). Prior art prior to the present invention

When people look for ways to reduce fluid resistance for a long time, attention has only been concentrated and limited to the form of the body, that is, the streamlined aspect of the object, and the current air drag reduction design of high-speed trains, missiles, and automobiles is still at this stage. After the creation of the boundary layer theory, after years of development, the drag reduction method can be roughly divided into four categories according to different ways of reducing the viscous resistance. One is the method of locally changing the fluid near the boundary, such as hovercraft technology and air lubrication technology. The resistance potential is considerable, but the specific technical and technological measures for the replacement of viscous fluids with very different viscosities and specific gravities at all boundaries are still difficult to solve completely. It is difficult to promote and is mainly used in transportation and mechanical engineering. The second type is to change and control the temperature of the boundary layer, or to change the flow velocity distribution of the laminar boundary layer by means of suction and so on to reduce the viscous resistance. It has been studied and applied in the field of aerospace and other outflows, which has been discussed in detail in a large number of monographs. , its drag reduction effect is limited. The three types of polymer dilute solution are used to reduce the resistance in the attached wall area, which can be used for drag reduction of fluids such as crude oil and water. However, the molecular weight of the molecular polymer is expensive, it is easy to be broken by shearing force, and the effect of drag reduction is limited. The four types use appropriate boundary materials (elastic materials) to make the boundary fully compliant, so that it is easy to generate dynamic response, and it vibrates with the T-S wave fluctuation of the laminar boundary layer. This is developed by bionics research. However, its drag reduction effect is still limited. The reduction of shape resistance basically remains in the streamlined line of the exploration object. There is also a method of arranging a channel connection head and tail inside the object to be dragged, so that the fluid passes through the channel from the front end to the rear end, reducing the front and rear ends. The pressure difference reduces the sticking resistance, but the channel friction resistance is large, which affects the drag reduction effect. Another notable method is to let the boundary surface of the object move with the movement of the fluid. This early discovery has been verified by an intuitive experiment, but this method has not been widely used, and it is almost forgotten. Moreover, the technical scheme has limited drag reduction effect, so it has not received much attention so far. These methods of drag reduction are widely discussed in various materials and monographs on resistance reduction; currently, various types of propulsion devices mainly provide propulsion, but have nothing to do with reducing fluid resistance. Purpose of the invention

The object of the present invention is to propose a new fluid drag reducing method and to provide a typical device for realizing the method, which can effectively reduce drag and can be widely used in water conservancy, aviation, navigation, underwater sports, transportation. Fluid reduction in the fields of transportation, defense, pipeline transportation, etc., and both propulsion functions (pressurization function). Technical solution adopted by the invention

In order to achieve the above object, the present invention mainly adopts such a technical solution: sequentially arranging at least one layer on each surface of the object to be drag reducing, and not less than one heavy movable wall surface per layer to separate the boundary surface from the surface of the object, so as to enable The fluid moves together, and the fluid near the surface is replaced by human intervention and the layer is stratified in a certain order. Each layer bears a certain relative speed, so that the boundary surface can reduce the relative speed of the fluid with less running resistance. To reduce or even eliminate fluid resistance at a speed that exceeds the speed of fluid movement; or to provide a movable wall system between the surface of the object and the fluid, often with a device, and at least one layer, each layer in a certain manner Not less than one moving wall in turn assumes a certain relative speed, and the internal space is replaced by a fluid-assisted drag reduction with lubrication and balance pressure. The movable wall on the contact side of the device and the fluid can move in the direction of fluid movement, after reaching the end point. Turn into the return trip, return to the starting point from the device, complete a cycle Since the movable wall on the side in contact with the fluid assumes the role of the boundary surface at this time, the laminar boundary layer and the laminar boundary layer are generated here, and the relative velocity between the fluid and the fluid is reduced as it moves in the direction of fluid movement. , thereby reducing the flow velocity gradient values at the close boundary of the laminar boundary layer and the laminar flow boundary layer, resulting in a decrease in the shear force of the fluid to the boundary surface and a decrease in the energy value directly diverging by the viscosity, that is, the frictional resistance is reduced; In the case of resistance and partial in-flow drag reduction, as an improvement, the inner channel surface connecting the front and rear ends of the object and the multi-layer multiple movable wall surfaces on both sides of the object reduce the friction resistance and increase the fluid discharge amount while also changing the top, The dynamic characteristics of the tail fluid have been reduced compared with the undisposed state, and the effect of reducing the viscosity-resistance effect has been increased. When a driving device is used to apply a driving force to the movable boundary surface such that the boundary surface moves faster than the fluid velocity or applies a driving force to the fluid, a thrust state occurs, and a negative pressure occurs at the front portion, and a positive pressure occurs at the rear portion, thereby partially adhering to the pressure. The resistance is offset and the fluid friction resistance disappears. It can be seen that the movable wall can function as both the thruster and the pressurizing device. Although its mechanical efficiency is similar to that of other propellers and pressurizing devices, it can make the fluid frictional resistance disappear. In the outflow state, the shape resistance can be reduced; at this time, the top and the tail of the object are laterally moved along the direction of the fluid movement or along the movable wall surface which is arranged in the direction of the fluid movement, and the flow is increased by the special device arranged at the top. The speed can also reduce the impact of the fluid on the moving wall; because the active wall device and the object can be seen as a whole in the force analysis at this time, the reduction of fluid resistance to the active wall surface is the reduction of the fluid resistance to the object, or the object to the fluid The resistance is reduced, and the relative motion of the object and the fluid is not affected. It will be completed. Although the above technical solutions are implemented by using devices in most cases, they are sometimes expressed as methods, and there are many methods for arranging movable walls, and the combinations and usages are various. Therefore, it is classified according to the habits of fluid mechanics. The surface of the obstructing object is arranged with multiple layers of multiple movable walls to separate the boundary surface from the surface and move with the fluid, so that the surface fluid is layered and flowed in a certain way. The specific technical scheme and the principle of drag reduction are : 1. Arranging one to multiple, multi-layer movable walls on the wall or surface of the object to be drag reduced. It can be considered that the outermost wall surface in contact with the fluid acts as a boundary surface, so that the movable boundary surface moves with the flow. Directional motion reduces the relative velocity of the boundary surface to the fluid to reduce frictional resistance with the fluid. When the outermost wall surface, that is, the boundary surface velocity is equal to the fluid velocity, that is, the relative velocity is zero, the fluid frictional resistance disappears.

For example, a device of the invention having only one layer of a movable wall similar to a conveyor belt disposed at a fixed wall surface under water, the soft film filling the movable wall can be moved with the rotation of the drum, and the fluid filled in the device is temporarily pressed by water. consider. As shown in Figure 1.

If the relative movement speed of the water flow and the fixed wall surface is V, then the device will obviously move under the driving of the water flow, and the speed of the soft film movement in the balanced state is Vi, and the resistance of the rotating bearing and the resistance of the soft film winding are negligible ( Technical measures can be taken to reduce the resistance), then: The upper water flow drives R _f equal to the frictional resistance of the lower and return water, ie:

R _f =Cf l/2pS(VV ₁ ) ² = Cf l/2pV ₁ ² Sx3=3R _fl (S is the area of the single-sided soft membrane)

Available (V-Vi) ² = 3 Vi ² , the solution is Vi = 0.366V,

Then the frictional resistance of the upper stream is:

Rf= C _f .l/2pSx(VV ²

= C _f .l/2pSV ² x0.634 ²

=0.402xCf.l/2pV ² S

And the power loss is W = C _f .l/2pSx(V-Vj) ³

_{^{= 0.255 C f .l / 2pV 3}} S

If the resistance of the drag reducing device is C _f .l/2pV ² S, the power loss is C _f .l/2pV ³ S

Conclusion: The active wall can greatly reduce fluid frictional resistance and energy loss.

2. The arrangement of the active wall and the circulation route vary with the drag reduction situation. From the force analysis, it can be found that the resistance of the device is mainly from the friction between the internal fluid and the movable wall. To reduce this resistance, the device can theoretically be used. The internal vacuum is drawn, and the non-contact force such as electromagnetic force is used to resist the external fluid pressure. However, the structure of the dynamic seal and the steering device is complicated. At present, the cost is expensive, and the dynamic sealing energy is large, and the vacuum is encountered. Complex issues must be carefully adopted. Therefore, in general, it should be replaced with a lubricating fluid with a small viscosity coefficient. It is sealed or semi-sealed, and multiple, multi-layer similar movable wall devices are arranged inside the device to reduce the running resistance, thus greatly increasing the drag reduction effect. . as shown in picture 2.

When the internal flow is drag reducing, the length of the mounting unit determines the starting point and the end position. The moving wall moves with the direction of fluid movement, and after reaching the end point, it turns into the returning path and returns to the starting point from the space between the boundary layer and the surface of the object. After completing a cycle, a space similar to the movable wall can be arranged in the space enclosed by the movable wall to reduce the running resistance, and multiple similar movable walls arranged in the space enclosed by the movable wall are temporarily called a layer, the same Each movable wall of the layer has the same direction of motion rotation; and the space enclosed by the return wall side of the movable wall and the surface of the object can be further arranged to a plurality of movable walls to reduce the running resistance, and the moving direction of the adjacent movable wall of each layer Instead; thereby forming a multi-layer multiple active wall system.

As shown in Fig. 4, in the case of outflow drag reduction, although similar arrangements can be made with reference to the inflow drag reduction, the following scheme is much simpler: the movable wall starts from the top of the object and moves from the top to the end, bypassing The tail of the object returns to the apex of the object from the other side to complete a cycle. According to the same circulation line, multiple movable walls can be arranged. Since the relative velocity of the return side fluid and the movable wall surface is large and the resistance is great, the solution is to arrange one on the other side of the object. The layers are from the multiple active walls of the attribute. The moving surfaces of the two layers are opposite in direction, and the return side is adjacent. Because the moving speed is similar, the resistance is very small. Only two layers of movable walls can meet the requirements. Of course, the actual situation is not ruled out. Need to have other forms of combination.

It is much simpler to arrange an object for rotational motion, and it is only necessary to arrange a plurality of concentric cylinder-like annular walls around its axis of rotation.

3. The layers and heavy wall surfaces of the above multiple movable wall surfaces are freely movable with each other, and no contact friction is generated or generated during operation. Each wall surface bears a certain relative speed, and sequentially generates a certain speed gradient, which will be a speed. The motion of V is decomposed into a plurality of motions whose velocity is much smaller than V. Although the sum of the latter speeds is still equal to V, the sum of the resistance and the energy loss is much smaller than the former, and the application is a ² + b ² < (a+b The principle of ² ; and the reduction of the relative velocity between the layers can cause the turbulent fluid to tend to flow in an orderly manner to reduce the Reynolds number and recover to the laminar flow state, limiting the generation and development of the vortex, thereby further reducing the total resistance and energy consumption. The principle of the relative velocity of each weight is to make the fluid resistance on both sides of each wall equal and opposite in direction (often the fluids in the layers are the same and the speed difference is equal), so that the consumption is less or not consumed. Balanced movement. Increasing the active wall weight and the number of layers can increase the drag reduction effect, and it is not necessary to continue to increase the number of layers and layers until the fluid between the walls returns to the laminar flow state.

As shown in Figure 3, taking the flywheel drag reduction as an example: A cylindrical flywheel rotates at a high speed V, and its outer sleeve is covered with n concentric thin-walled rigid cylinders as multiple movable wall devices. Suppose we do not consider the flywheel and the thin wall circles. The influence of the end of the cylinder, also neglecting the influence of the thickness and spacing of the cylinder, and setting the inner and outer surface area of the flywheel and the cylinders of each layer are S, then the cylinders of each layer can generate a velocity gradient which decreases from the inside to the outside, and each equilibrium state is set. The relative velocities between the layers are ΔVi, Δν ₂ , Δν _{3 ,} Δν„, and the specific gravity of the fluid between the cylinders is ρ. The m-th cylinder is subjected to force analysis and is subjected to two forces. One is the driving force of the inner fluid to it, the size is C _f xI/2pAV _m ² S, and the other is the resistance of the outer helium fluid to it, the size is C _f xl/2pAV _m+1 ² S, the two forces are equal in magnitude In the opposite direction, AV _m = V _m+1 can be derived. The same conclusion can be derived for each cylinder. It can be concluded that the relative speed of each layer is V/n, due to the cylinders. Considering the constant velocity motion in the equilibrium state, the work done by the inner and outer fluids cancels each other. Theoretically, there is no additional energy consumption. It is known that the fluid friction force of the flywheel is C _f xl/2pSx(V/n) ² = l/ _n ² xC _f xl/2pV ² S, the power loss is l/n ³ C _f xl/2pV ³ S, which means that the theoretical friction resistance and power loss of the flywheel after the drag reduction is 1/n ² and l /n ³ . The drag reduction effect in plane motion can also be derived by a similar method (the process is abbreviated), and the forces of the fluid received on both sides of each active wall are basically equal in magnitude and opposite in direction, and are in motion balance state, and the dragged and movable walls In the force analysis, it should be regarded as a whole. The fluid resistance of the object depends on the relative motion between the active wall and the fluid in contact with the fluid at the outermost layer. Theoretically, the three- and four-layer (heavy) active wall is It can reduce frictional resistance by more than 90%.

Of course, theoretically, the movable wall layer and the weight can be increased without limitation, and the drag reduction effect is continuously increased. However, although the fluid movement speed is reduced, there is still a small amount of energy dissipation when the friction is generated, and the fluid is turned. There will be a certain loss of kinetic energy, there is resistance at the shaft bearing (the resistance can be calculated according to F _t =0.005F _T d ₀ /D when using mechanical bearings, F _T is the positive pressure at the shaft, do and D are the bearing inner diameter and the shaft Diameter), the winding resistance on the rotating shaft and the rotating wheel when the movable wall is turned (according to the conveyor industry experience formula, F 9B (140+0.01F/B) d/D, where B is the width and F is the active wall tension, d is the thickness of the active wall, D is the steering diameter, the unit is Newton, but it is used to be significantly larger here. These require the fluid to replenish energy, so that even if it is filled with the same fluid, when the movable wall is on both sides When the force of the fluid is equal, there will be a slight difference in the velocity of the fluid on both sides, and the side providing the driving force is slightly larger than the other side, which has a maximum limit on the increase of the movable wall layer and the number of the weight. These resistances can account for a certain proportion in gas-based low-speed applications, and in other cases, the proportion is small, so the theoretical analysis can be ignored.

4. Displace the fluid with a small viscosity coefficient for lubrication and maintaining pressure balance in the space between the active boundary surface and the surface of the fixed wall or the object to be drag reduced, and close or semi-closed to reduce the running resistance. In some cases, vacuum can also be drawn, and non-contact forces such as electromagnetic force can be set to resist fluid pressure. The principle of selecting fluid for lubrication is to select a fluid with small viscosity coefficient and low density. If the fluid to be dragged is a gas, hydrogen, helium and other gases are preferred. (But if dangerous hydrogen is selected, the sealing requirements are strict) If the fluid to be dragged is a liquid, a fluid having a small viscosity coefficient and a lubricating effect, such as a polymer solution or the like, is selected. If gas is selected, care should be taken to maintain a balance between air pressure and hydraulic pressure. In many cases, the same fluid can also be charged.

5. The movable wall surface can be made of a material with certain elasticity, so that it is easy to generate dynamic response, vibrate with the T-S wave fluctuation of the laminar flow boundary layer, and increase the drag reduction effect. The principle and the fourth method in the background art the same.

6. When reducing the sticking resistance (mainly in the case of outflow drag reduction and a small part of inflow drag reduction), as an improvement, the multi-active multiple wall is arranged on the inner channel surface connecting the front and rear ends of the object, reducing frictional resistance and increasing The fluid discharge quantity also changes the dynamic characteristics of the top and tail fluids, and the pressure difference has been compared with the undisposed state. Reduced, has increased the effect of reducing the effect of viscosity and pressure. When a driving device is used to apply a driving force to the active boundary surface so that the boundary surface moves faster than the fluid velocity, a thrust state occurs (which can partially replace the function of the propeller), and a negative pressure occurs at the front and a positive pressure at the rear, thereby The sticking resistance is offset. Similarly, the sides of the object can also be regarded as non-closed passages, and the movable wall surfaces on both sides can greatly reduce the frictional resistance of the fluid. When the driving force is applied to make the moving wall movement speed higher than the speed of the fluid to be reduced, the frictional resistance of the fluid disappears. On the contrary, there is a thrust state, and a negative pressure occurs at the front, and a positive pressure occurs at the rear, which is offset by the sticking resistance. Other fluid pumping devices can be added to speed up the fluid transport speed. When the fluid discharge speed reaches a certain speed, When the critical value (which should be the product of a certain undetermined coefficient and the cross-sectional area and velocity of the object), the shape resistance disappears, and the corresponding "sticking pressure" appears when the discharge speed is continued to increase.

7. Arranging the movable wall surface along the direction of fluid movement or along the direction of fluid movement in the top and the tail of the object can also reduce the impact force of the fluid on the object (ie, the shape resistance), and the arrangement should be considered to conform to the streamline principle, and Smooth connection without excessive mutation, minimize the angle between the long axis of the object to reduce the impact force and divergence energy directly from the mechanical impact, and take a part of the active wall for analysis. Each slope can be decomposed into two planes, one is a vertical plane perpendicular to the direction of fluid motion, and the other is a horizontal plane parallel to the direction of fluid motion, both sides moving backwards and toward both sides of the object along the direction of fluid motion. The vertical rearward movement reduces the relative velocity of the fluid and reduces the impact force of the fluid (ie the shape resistance). When moving to the sides, the friction will discharge the fluid to the sides; the horizontal rearward movement reduces or even eliminates the The frictional resistance of the fluid, moving to both sides also pushes the fluid to the sides; the moving wall is arranged in the direction of the tail in the direction of fluid movement Introducing fluid into the end of the object, increasing the pressure of the fluid on the end of the object to reduce the pressure difference between the front and the rear; therefore, the movable wall disposed at the top and tail can not only directly reduce the fluid impact force and frictional resistance, but also have the function of pumping and discharging fluid and assisting drag reduction. . The Nas-Tok equation is also applied to the top fluid. It is also found that the fluid and kinetic energy changes are reduced after the active wall is placed, and the energy and kinetic energy are reduced.

8. The fluid exerts shape resistance on the impact of the head of the object. In fact, part of the shape resistance is frictional resistance. That is, when the fluid velocity on the top surface of the object is decomposed, it is known that the velocity component parallel to the surface of the fluid actually causes frictional resistance. It can be eliminated by arranging the moving wall surface, and the velocity component perpendicular to the surface causes the impact force, but this component is smaller. The dragon is smaller when the shape of the object head conforms to the streamline shape, and applies a lateral velocity to the incoming flow. It is possible to reduce or even eliminate the velocity component perpendicular to the surface of the object, make the velocity vector direction parallel to the surface, convert the shape resistance into frictional resistance, and then arrange the movable wall surface to reduce the frictional resistance, thereby reducing the shape resistance. For objects with sharper heads (such as pointed at high-speed aircraft heads), a modified propeller-like mechanism can be used to apply lateral velocity to the incoming flow, as shown in Figure 16, but with its "blade" plane and incoming flow direction. It is basically parallel, so that the shape resistance is small, and the blade produces a lateral velocity when the blade rotates, and at the same time, the centrifugal force is applied to the lower fluid to be swayed to the periphery, and may be sequentially arranged one or more to reduce the fluid. Mechanical impact on the top of the object; for the case where the head is relatively flat, a multi-layer blade mechanism can be added to the movable wall to apply lateral velocity to the fluid, and the protective blade should be used when the movable wall velocity is less than the flow velocity. The thin flange direction is opposite to the flow to reduce the shape resistance caused by the blade itself.

The above method can be implemented according to the method points, and a specific device is designed to be implemented. There are many methods for arranging the movable surface on the surface of the object. The technical feature of the device used in the present invention is that the device and the fluid contact side are provided with multiple movable walls. It can move with fluid motion and reduce the relative velocity with the fluid; when the driving force is applied, its relative movement speed with the object to be dragged can exceed the speed of fluid movement, thereby eliminating fluid friction resistance and reducing shape resistance.

The device of the invention is installed between the surface of the object requiring drag reduction and the fluid, and has different compositions and combinations depending on the use situation, but can be basically divided into the following parts: movable wall mechanism, steering mechanism, outer casing and Support mechanism, sealing mechanism, internal lubrication fluid and other auxiliary mechanisms, etc., and can be divided into multiple installation units of the same size or different according to the installation process. The composition of each unit is basically the same, and the organic combination of each unit is composed. A complete mobile wall system unit.

As shown in Fig. 5 to Fig. 1 and 2, the movable wall surface mechanism refers to a soft film type member which can be circulated and moved like a conveyor belt in the device, and is a main execution member for performing a drag reduction method, and can be made of nylon or rubber. Made of high tensile strength materials or fabrics (sometimes resistant to temperature), and with a certain elasticity, it is easy to produce a dynamic response, which can vibrate with the S-wave fluctuation of the laminar flow layer; The specific gravity is set to be the same as or close to the fluid to be contacted, to reduce the unfavorable load caused by its own weight, and to cover the polytetrafluoroethylene self-lubricating material with a small friction coefficient to reduce the mutual contact between the adjacent movable wall surfaces. Friction (compared to the gas when the drag reducing fluid is gas); the length, width and other parameters are determined according to the installation unit and the associated layer and the number of the weight. If there is a need for steering, the width direction is set to a certain amount of stretching; Two side belts with strong tensile strength and double-sided externally applied high-strength friction material are provided on both sides along the length direction. The side belts are wrapped around the "rotor" of the steering mechanism. Moves with the "rotor" and moves with the movable wall member; the movable wall member can also be laid with special materials due to the use of functional requirements, such as the outermost movable wall to increase the power of the fluid when the outflow is increased or to prevent internal When the flow density of the fluid is too small and the flow velocity is low, the movable wall surface cannot be driven, and a rough surface or a receiver such as a scraper can be arranged to receive fluid energy to drive the movable wall surface, or to increase the pushing capacity; Thick wall surface or steel wire rope reinforcement, such as adding a thin stick to resist unbalanced pressure, or laying a wire or a composite magnet material for driving or balancing external force by electromagnetic force, for example, to prevent adjacent The movable wall faces are in contact with each other, and the same pole magnet such as a flexible composite plastic magnetic or rubber magnetic strip can be attached to the opposite movable wall surface to generate a repulsive force, even if the contact friction is unavoidable due to the small positive pressure and the friction coefficient. The generated friction is small; and the convex magnetic strip arranged in a certain manner can also prevent the movable wall from running off and positioning The sealing effect, and Resist the unfavorable load caused by gravity. When the fluid in contact with the movable wall is a gas, the weight of the movable wall will cause it to have a large sag. Although the support or the drum can be supported at intervals, the support or the drum will increase the contact friction. The shape resistance is additionally generated, and the installation thickness is not easy to control. Therefore, the magnetic material can be laid in the movable wall surface, and the magnetic device is also disposed on the solid wall of the object. The spacing and the magnetic field strength should be determined strictly according to the electromagnetic force to eliminate the gravity. The impact.

The steering mechanism is a mechanism for driving and assisting the moving wall member to change the moving direction to complete the circular motion, generally consisting of a rotating drum and an auxiliary mechanism thereof, and the rotating drum is arranged symmetrically by the rotating shaft, its bearing and the bracket, and fixed on the rotating shaft. Many pairs of circular runners are formed, just like the belt is wound on the pulley in the belt drive, the side belt on the movable wall is wound on the runner, and the runner structure is similar to the pulley of the transmission, on the outer circumference There are grooves to prevent the sideband from deviating. The number of runners is determined by the number of the movable wall of the layer. The runners with different radii on the drum determine the relative velocity between the heavy moving walls overlying the inflow. In the drag reduction, a pair of rotating drums are arranged at both ends of each layer, which basically meets the requirements, and then multiple movable walls are respectively wrapped thereon to form a layer. According to the scheme determined by the drag reduction method, the return wall side of the movable wall and the surface of the object are enclosed. The same method can be used to arrange one layer to the multi-layer movable wall surface, and the adjacent movable wall surfaces of each layer have opposite movement directions, in order to control the relative speed between the layers. A pulley can be arranged outside the rotating shaft of each layer of the drum, and each pulley interacts with a mechanical transmission such as a belt drive to control the relative speed between the layers; the device for the external flow is also determined by the drag reduction method. In the way of arrangement, the device from the attribute quality can be installed separately on both sides of the object and on the top part of the object, or can be installed as a circulation line; thereby forming a multi-layer multi-active wall system device.

In order to drive the outermost wall surface to generate thrust, the driving drum is driven, and the rotating shaft adopts a built-in driving motor to drive the rotating drum. The motor driving is a relatively mature technology in the conveyor industry, and of course, other methods are not excluded. The drive, for example mechanical transmission, transmits kinetic energy; the drive drum can be arranged along the outermost active wall, the number and position of the arrangement being determined as desired, and not limited to the active wall turn.

Sometimes the steering drum is set up because the diameter of the rotating drum is large to reduce the total thickness of the movable wall to avoid the shape resistance caused by the outflow and the effective overcurrent sectional area during the inflow, and there is no between the runner and the rotating shaft. Fixed, but the bearings can be rotated freely, the radius between the runners is not much different, the ideal state is roughly equal to the distance between two adjacent movable walls, the sidebands of the movable wall are turned and twisted in turn on the steering drum after being turned by the drum On each of the runners, the thickness of the installation is reduced.

The gap between the layers can be replaced by a fluid with lubrication and pressure balance. The principle of fluid selection for lubrication is generally a fluid with a small viscosity coefficient and a small density. If the fluid to be dragged is a gas, hydrogen and helium are preferred. Wait for the gas, but if the dangerous hydrogen is selected, the sealing device is strict. If the drag reducing fluid is liquid, choose a fluid with a small viscosity coefficient and a lubricating effect, such as a polymer solution. If you choose a gas, you should pay attention to keep it. The balance between pressure and hydraulic pressure, especially the vertical surface of the device used as the movable wall surface, should be specially equipped or specially designed to maintain the pressure balance. For example, a thin stick can be placed in the width direction in the movable wall to strengthen the liquid resistance. The ability to unbalance the pressure, the transverse baffle is arranged in the gas chamber to divide it into a plurality of independent small air chambers in the vertical direction, and the dynamic sealing design is performed between the baffle and the movable wall surface, and each small air chamber maintains a certain pressure value ( It is often equal to the pressure of the liquid outside the midpoint of the gas chamber to make the sum of the inner and outer pressures equal.) The unbalanced fluid pressure of the small gas chambers at the upper and lower ends is balanced by the electromagnetic force generated by the method of arranging the permanent magnet or the like, or The push and pull forces generated by the designed sealing mechanism are balanced. These are borrowed to some extent by the technology of the air cushion conveyor. In some exercisers, magnetic suspension technology can also be considered to balance the uneven fluid pressure. The pressure changes encountered during operation generally consider that the lubricating fluid is closed to change its volume with pressure, so that it can be balanced against the pressure. For example, the side belt and the positioning rib can also be arranged like a spiral labyrinth seal. Therefore, when the upper and lower wall positions can be controlled, the non-contact dynamic seal is formed, and the rotating shaft and the outer casing are combined to form one or more sealed or semi-enclosed spaces, and the rigidity of each wall surface is increased, the initial tension is preset, the number of rotating drums is increased, and the installation is reduced. Unit size and the addition of electromagnetic force resistance device and fluid pressure compensation device can improve the ability to resist external pressure changes. As for the impact force on the movable wall placed on the top of the object during outflow, the stiffness of the outermost wall should be strengthened. The cylinder, and the outermost wall at the top position is separately provided with a circulation line, or a plurality of drums can be arranged to directly resist the fluid impact (the rotating drum doubles as the movable wall and the driving device), so that the part is cancelled most The outer active wall becomes a special case. In the case of severe pressure changes that result in dramatic changes in fluid volume (especially in the presence of gas), the seal can be eliminated and external fluids can be easily accessed as much as possible to maintain pressure balance.

The mechanism for applying lateral velocity or pumping fluid to the incoming flow at the top of the object may be provided with an improved propeller structure or a blade and a blade as needed.

Regarding the design and selection of the sealing mechanism, the width direction sealing device is mainly arranged along the boundary of the outer casing or the supporting edge and the movable wall surface, and the selection is the same as the general dynamic sealing design; the sealing along the length direction is generally arranged between the mounting units. The moving speed is the same and between the adjacent outermost movable wall surface and the movable wall surface (if necessary, a sealing can be provided between the inner movable wall surfaces), and a strong magnetic substance with strong penetrating force is placed in the movable wall surface outside the side band. Externally applied to the same or similar material as the gasket for sealing, (can also be directly attached to a composite magnetic strip such as a rubber magnetic strip). When two adjacent movable walls reach each other at the starting point, the magnetic substances on the two movable walls attract each other to generate suction. Automatically close and press the gasket material to form a seal. When moving to the end, the two movable walls move in their respective directions, respectively, and the seal is broken under the action of tension. In the process, the reaction is relatively rapid, so the interactive cycle occurs. That is to say, the seal is a live button type, which can be pulled or synthesized as needed; in the case where the reaction speed is not required Designed to open and close mechanical locking device may refer to the principles of the fastener means. If the device is filled with dangerous goods such as hydrogen that are not allowed to leak, the sealing device is strict, and even a magnetic fluid seal may be considered. If a fluid with a partial leakage is allowed, It is also possible to use a general seal design. In many cases, the internal and external fluids are the same, and the seal can be eliminated. In addition to forming a relatively closed space, the sealing mechanism prevents the lubricating fluid from escaping and prevents impurities from entering, and can also strengthen the connection of the movable wall through its connection, so as to form a relatively closed space, have certain stability, and have certain resistance imbalance. Ability to force.

Sometimes the device is provided with a housing for the convenience of processing or preventing the lubrication fluid from corroding the surface of the object. The manner of fixing the steering mechanism and the outer casing and the outer surface of the outer surface of the object to be dragged can be flexibly determined according to requirements, and sometimes the outer casing can be eliminated. Replaced by the surface of the object. The end casing can also resist the impact of the steering fluid on the end, and sometimes a support can be provided to balance the centrifugal force generated by the fluid steering where there is no casing against the fluid impact at the movable wall turning position.

In the case of high speed, such as the drag reduction and propulsion of aerospace and aerospace vehicles, the above schemes such as ordinary motors and mechanical bearings fail, so they should be driven by high-speed motors. At this time, the shaft is equivalent to a high-speed motor spindle. A related art of a high speed electric spindle can be employed. In the above-mentioned manner of driving the movable wall surface, the mechanical rotation has failed, the side belt can only be guided, and the electromagnetic force driving method is still applicable, that is, the metal mesh or the wire is arranged in the movable wall to pass current or cause an induced current, Or arrange a strong magnetic material, and another electromagnetic field to drive it, as shown in Figure 17, this way is the same as the linear motor, the active wall is equivalent to the secondary of the linear motor, and the device with external electromagnetic field is equivalent In the primary of the linear motor, the thrust generated by the movable wall is also transmitted directly to the object through the primary and is no longer transmitted through the bearing and bracket of the rotating shaft. The steering can also be placed at the primary and the retaining position (or similar to the stator of the high-speed motor). The mechanism can assist the steering, the lateral force under the condition of starting or braking at the rotating shaft can also be balanced and positioned by magnetic levitation or even superconducting technology. The rotating shaft and the rotating wheel can even be set as primary or secondary respectively, for example in The wires are arranged on the rotating shaft to generate an induced current, which is controlled by the conductive wheel and the sideband. System current activities within the wire introduction wall surface may be controlled to thereby control the force activities where each heavy wall surface and the like, the technical details with reference to linear motor technology. Controlling the relative velocity of each heavy moving wall and the fluid and the object to be dragged within a certain value (if not exceeding the speed of sound) can prevent the shock wave from being generated and eliminate the shock wave resistance, but there will still be somewhere on the top of the moving object and the rotating shaft runner. Shock waves appear, and should be considered and arranged in the specific design. In the case of lower speed applications such as ships and submarines, such propulsion schemes can also be used. In seawater, electromagnetic fluid propulsion technology can also be combined. It has the characteristics of high power, fast start, high energy utilization, etc. Large investment and high technical requirements.

In addition, auxiliary mechanisms such as safety operation monitoring mechanisms, various types of sensors and control lines, various fairing mechanisms, lubrication fluid replenishing mechanisms and pressure compensation balancing mechanisms are also important components of the device, which are basically the same as the prior art. Some parts of the low-speed motion can directly refer to the relevant content of the conveyor technology.

The present invention and its apparatus are equivalent to solving the object table in relation to the first type of method in the background art. The replacement technique and process measures of the viscous fluid with different viscosity and specific gravity are realized, so that the considerable drag reduction potential can be explored; compared with the second method, it is easier to control the flow when changing the boundary surface and the relative velocity of the fluid. State transition, and the active wall of each layer bears a certain relative speed to reduce the energy consumption, and provides the prospect of eliminating the shock resistance, and the drag reduction effect is significant; compared with the third method, it makes the polymer It is possible to reduce the possibility of failure due to shearing, and the high molecular polymer is expensive, and in use, in consideration of economy, the injection concentration is often lowered to affect the drag reduction effect, and the present invention fixes it without causing it to escape. The high concentration can be used for a long time, thereby saving the cost and increasing the drag reducing effect, and the invention is not limited to the fluid drag reduction of water and petroleum, and has a wider application range. Compared with the fourth method, the invention has both its drag reduction characteristics and the advantages of other methods, thereby further reducing the resistance. For the purpose of reducing the shape resistance, it has been mainly limited to the selection of the streamline type line, and the present invention arranges the movable wall surface reduction item and the tail pressure difference from the both sides or the internal passage on the basis of retaining the streamline type drag reducing effect, thereby The drag reduction effect is increased, and the streamlined top and tail surfaces are further arranged with the movable wall surface to further increase the drag reduction effect; and it is more important to note that when the present invention is used as a drag reduction propulsion method or tool, not only the shape resistance is reduced, but The frictional resistance of the fluid disappears, which is unmatched by any other drag reduction method and propeller at present, and therefore the present invention is a major breakthrough in the fluid drag reduction method. Moreover, in most applications, the invention has the advantages of simple structure, low cost, convenient safety, and favorable industrialization, and has wide application prospects in various drag reduction fields. DRAWINGS

Figure 1 is a schematic view showing a simple drag reduction of the device of the present invention;

2 is a schematic view showing the arrangement of a plurality of movable walls and a circulation route in an inflow state;

3 is a schematic view showing a movable wall surface disposed outside a self-rotating moving object such as a flywheel;

Figure 4 is a schematic view showing the arrangement of multiple active walls and a circulation route in an outflow state;

Figure 5 is a schematic view showing the structure of the driving drum;

Figure 6 is a front elevational view of the drive drum;

Figure 7 is a schematic view showing the structure of the steering drum;

Figure 8 is a front elevational view of the steering drum;

Figure 9 is a schematic view of the movable wall surface deflected by the steering drum to reduce the installation thickness;

Figure 10 is a schematic view showing a flexible positioning magnetic strip attached to the movable wall surface;

Figure 11 is a schematic view of the relative speed of each layer of the drum controlled by the belt drive;

Figure 12 is a schematic view showing the structure of the movable wall;

Figure 13 is a schematic view showing the division and positional relationship of the installation units of the oil pipeline in the first embodiment; Figure 14 is a schematic view showing the division of the water supply channel installation unit in the second embodiment;

Figure 15 is a longitudinal sectional view showing the water body drag reduction installation of the side wall type hovercraft in the fourth embodiment;

Figure 16 is a schematic cross-sectional view of the improved propeller;

Figure 17 is a schematic diagram of the primary drive of the linear motor placed at the active wall turn with current.

In the drawings: 1. Rotating drum and bearing; 2, bracket, 3, soft membrane, single or multiple movable wall; 4, end seal; 5, device shell or support; 6, flywheel and other self-rotating moving objects 7. Active wall outside the rotating object such as flywheel; 8. Main active wall system; 9. Subordinate active wall system; 10. Rotary shaft and bearing; 11. Each wheel (on the rotating drum); Wheel (steering wheel); 13, runner bearing; 14, rubber magnetic strip with lubricating layer on the surface; 15, dragged object; 16, steering drum; 17, driving drum; 18, each layer of drum 19 on the side of the shaft; 19, transmission belt; 20, side belt; 21, movable wall belt; 22, installation unit; 23, oil pipeline wall; 24, channel side installation unit; 25, channel bottom installation unit; Tube and bearing and shaft bracket; 27, air cushion chamber; 28, air cushion hull; 29, paddle; 30, paddle shaft; 31, active wall with current; 32, arc type primary. detailed description

Example 1

Figure 13 is a schematic diagram of the division of the drag reducing installation unit of the petroleum conveying pipeline and the positional relationship of each unit. If the pipe diameter is about 1100mm, the width of each unit is about 500~600mm, and three layers are set, one to two and two from the inside to the outside. The triple active wall, the average specific gravity of the movable wall is the same as the specific gravity of the oil or lubricating fluid, which can eliminate the sag caused by gravity, and at the same time, a flexible composite magnetic strip is attached to prevent or reduce the friction of the touch. A special joint is arranged at the pipe joint, and a driving drum, a steering drum and the like are arranged therein, and the movable wall surface turning manner is the same as that shown in Fig. 9. The thickness of each heavy movable wall surface installation (including its own thickness and the weight interval) is about 4 mm. The total thickness is about 4.4cm, and there is a live button sealing mechanism. The fluid for lubrication is a petroleum or water mixed with a cerium concentration 髙 molecular polymer. Although the over-flow area is reduced by about 20% after installation, the speed is increased by 2-4 times under the same energy consumption. If combined with the water circulation technology, it can be transported under normal temperature and pressure. Example 2

The device of the present invention is installed in a horizontal water delivery channel to reduce the frictional resistance of the water to the channel wall. FIG. 14 is a schematic diagram of the division of the mounting unit, and can be increased when the cell width is too wide. The top is air, so there is no drag reduction device; five layers of movable walls are installed along the channel wall, and each layer is one-, two-, three-, three-, and five-fold moving walls from the channel wall. Face, with a length of 100 m as a mounting unit, a recessed groove is provided in the wall of the canal every 100 m. The drive drum is placed in the trough, and the rotating drum and the inter-layer contact mechanism are turned. The movable button seal of the present invention is disposed between adjacent outermost movable wall surfaces of each mounting unit, and a multi-stage dynamic seal is arranged between the end baffle of each unit and the movable wall surface, and the space enclosed by the movable wall surface is filled with high density. The aqueous solution of the high molecular weight polymer is used as a lubricant, and the driving drum is only provided with a small power driving motor to supplement the energy of the frictional resistance loss, or simply without a driving motor, so that the channel has a certain slope, and the kinetic energy converted by gravity energy is supplemented. The friction loss causes the water flow to maintain a high speed, and a conduit can be provided at each unit connection to derive the bottom sediment, as shown in FIG. If the water flow is to be lifted or accelerated, a mounting unit is installed above the water channel. The unit only needs one or two movable walls (the upper part is in contact with air), and the wire is laid in a certain way in the movable wall to make it a straight line. The secondary of the motor, and the primary that is fixed to the channel wall by the bracket. (The blade can also be added outside the movable wall to increase the ability to push the drainage flow, but the blade should avoid the primary position to avoid excessive air gap). The current is caused by the active wall to push the water flow upward along the bottom of the slope. Due to the high power and high energy conversion rate of linear motors, such channels will have great applications in long-distance water transfer projects and transport waterways. Example 3

Applying the invention to reduce the fluid resistance on the surface of the underwater floating body of a small waterline ship: the floating body is a cylinder having a diameter of about 1.5 meters, and is divided into three mounting units, and the positional relationship profiles of the three mounting units are the same as those of the first embodiment. The cross-section diagrams are very similar. The difference is that the hexagons enclosed by three units are outside the cylinder. Each unit is about 1 meter wide. The longitudinal section is basically the same as that in Figure 4. Note that the three units intersect at the head and tail. The arrangement, two of which are turned at right angles at the head and tail, and the inboard current drag reduction on the outside arranges multiple movable walls to reduce the resistance across the top. Each unit is arranged with five movable walls, and the return side is arranged with subordinate movable walls. It is also five-fold. Each weight is about 5mm thick and 5mm apart. The same polarity flexible magnetic strip is adhered to prevent or reduce contact friction. Every 2 meters or so, there is a driving drum, a built-in driving motor, and the movable wall side belt is modified by a high-power transmission belt. The movement of the fluid pressure at the top position is complicated, so the driving drum is further added, and the outermost wall is thickened. To keep the device stable. A sealing mechanism is arranged at each relevant part, a lubricating fluid is a high concentration polymer aqueous solution, and a battery or the like can be arranged in the floating body, so that after the current is passed, the plurality of driving motors drive the movable wall to move backward at a speed greater than the speed, thereby Propulsion is generated and the fluid frictional resistance disappears. The principle is as shown in Fig. 16, and a multi-layer modified propeller device is added on the top to reduce the shape resistance. Example 4

The underwater part of the side-mounted hovercraft is improved, and the invention is used to advance and reduce the resistance. FIG. 15 is a schematic longitudinal cross-sectional view, and the air-cushion apron of the hovercraft's head and tail is cancelled and replaced by two hollow large drums. Wrapped up Moving the wall, but because the hull has been lifted off the surface of the water, the drag reduction effect is not very large, so the part of the device is saved and the drum is reserved, which is equivalent to the special case where the movable wall is arranged only at the beginning and the end. Although the drum can provide partial buoyancy, the hull load is mainly supported by buoyancy provided by the air cushion chamber, and the dynamic seal design is performed between the drum and the air chamber and the movable wall surface of the side wall to reduce the pressure loss of the air chamber. As shown in Figure 17, the outer wall of the drum is laid with a wire to make it a "linear motor" secondary. The primary part of the "linear motor" is placed at the junction of the hull and the drum. After the power is turned on, the drum rotates at a high speed to discharge the water to the rear of the drum. Generate thrust. Since the water flow is not discharged to both sides, not only the shape resistance is reduced, but also the wave resistance is reduced or even eliminated. The radius of the drum is relatively large, so that it can cross the height of the wave. The wave can only impact the lower half of the drum, and its impact force becomes the driving force of the drum rotation, thereby reducing or even eliminating the resistance of the tower; and the two rigid sidewalls The 5~10 active wall is also set according to the external flow drag reduction mode, and the driving device can also be provided to provide the propulsive force, thereby reducing or even eliminating the frictional resistance of the sidewall fluid.

Claims

A method for reducing fluid resistance, characterized in that: at least one layer is arranged in sequence on the surface of the object to be drag reduced, and at least one movable wall surface of each layer is subjected to a certain relative speed to perform a predetermined amount of fluid flow. The surface fluid of the object is layered and orderedly flowing; the movable wall surface in contact with the fluid bears the role of the boundary surface to separate the boundary surface from the surface of the object, and the boundary surface moves with the fluid movement without changing the motion state of the object, reducing the fluid and the fluid Relative velocity.

The method according to claim 1, wherein a driving force is applied to the movable wall surface to move at a speed exceeding a speed of movement of the fluid, and a force is applied to the fluid to generate a propulsive force.

Right

3. The method according to claim 2, wherein: when reducing the sticking resistance, the fluid running channel is disposed at both ends of the fluid pressure difference, and at least one layer and each layer are not less than one heavy movable wall. Arranged on the surface of the channel in turn, and set up an auxiliary device that can draw fluid.

4. The method according to claim 1, wherein: in the case of internal flow, no less than one movable movable wall is built in the space enclosed by the movable wall, and the movable wall and the surface of the object are not arranged. Less than one layer, each layer has no less than one movable movable wall surface, and each heavy movable wall surface in the same layer turns to the same and shares a certain relative speed, so that the Reynolds number of each heavy fluid is reduced; Each layer in turn assumes a certain relative speed, so that the running resistance between the layers is reduced; in the case of the outflow, no less than one movable movable wall is arranged along the circumference of the object, and the circulation route is also along the circumference of the object, and the return side is arranged The layer motion turns to the opposite subordinate multiple active wall surface, and the return side is adjacent and the movement direction is the same; each heavy active wall surface bears a certain relative speed, reduces the Reynolds number of each heavy fluid, and reduces the total resistance; The principle of the relative velocity of the wall is that the force and other resistance of the fluid received on each side of each wall are equal or substantially equal. In the opposite direction, the balance of motion is maintained without any consumption or reduction of external energy consumption.

5. The method according to claim 1, wherein: the fluid in the space enclosed by each layer and each of the heavy moving walls is filled with a fluid having a small viscosity coefficient, a lubricating action and a balanced pressure, so that it does not escape and Can maintain pressure balance.

6. The method of claim 1 wherein: when reducing the shape resistance, a lateral velocity is applied to the incoming flow at the top of the object to change the direction of the incoming velocity vector.

7. A drag reducing propulsion device for reducing fluid resistance, disposed between a surface of an object to be drag reduced and a fluid, characterized in that: at least one layer is arranged in sequence with the fluid contacting side, and a movable wall surface of not less than one weight per layer is arranged. The movable wall moves with fluid motion without affecting the motion state of the dragged object itself.

8. The apparatus according to claim 7, wherein: the driving device is provided to move the movable wall surface in a direction of fluid movement at a speed exceeding a moving speed of the object, and apply a driving force to the fluid to generate a propulsive force and reduce a pressure difference. .

9. Apparatus according to claim 7 wherein: the movable wall is wound by a plurality of runners Arranged on the cylinder, each pair of runners is laid with a movable wall, so that multiple layers of movable walls are arranged in the space enclosed by the ones, and one to two layers of movable wall devices are arranged according to the same method between the movable wall surface and the surface of the object. When the outflow is drag reducing, the device is arranged along the circumference of the object, and the subordinate multiple moving walls are arranged side by side on the return side, and the return side is adjacent and the moving direction is the same.

10. The device according to claim 7, wherein: the speed distribution of the movable wall surface over which the cover is determined by the difference between the radius of the upper wheel of the drum, and the layers are controlled by the transmission between the layers of the drums. The rotation speed and steering, the principle of movement direction and speed distribution is to balance the force and other resistance of the fluid received on both sides of each heavy moving wall, so that the energy consumption required to maintain the balance state of motion is reduced.

11. The device according to claim 7, wherein: the space enclosed by the movable wall surface and the space enclosed by the surface of the object is filled with a fluid for lubricating and balancing pressure, and the sealing member is arranged to form a closed space. And let it not be lost.

12. Apparatus according to claim 11 wherein: said sealing member is a snap-fit structure that alternately opens and recombines as the active wall operates.

13. Apparatus according to claim 7 wherein: the top of the object is provided with means for applying a lateral velocity to the incoming flow which changes the direction of the incoming velocity vector.