Multi-layer movable wall fluid resistance-reduction and propulsion device

Abstract

The invention provides a fluid drag-reducing and propelling device with plural layers of active wall surfaces, able to reduce resistance to fluid, arranging one to plural layers of active wall surfaces able to circularly rotate on the surface of an object in the flowing direction of the fluid, where one to multiple active wall surfaces are arranged in the space formed by each layer of active wall surface, all the active wall surfaces moves with the fluid, reducing their relative speed to the fluid so as to reduce frictional resistance and energy consumption; by applying driving force to make the moving speeds of the active wall surfaces greater than that of the fluid, it can produce propelling force, able to reduce pressure difference between the two ends of the object and thus reducing shape resistance and making the frictional resistance disappear. And it can be widely applied to various drag reducing occasions of fluid.

Description

Technical field [0001] The present invention relates to a device that reduces fluid resistance (including frictional resistance, viscous pressure resistance and similar resistance) and has a propulsion function (pressurization function). Background technique [0002] For a long time, when people are looking for ways to reduce fluid resistance, their attention has been only focused and limited to the shape, that is, exploring the streamlined aspect of objects. 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 methods can be roughly divided into four categories according to different ways to reduce the viscous resistance. The first category is the method of locally changing the fluid near the boundary, such as hovercraft technology, air lubrication technology, and its reduction. The resistance potential is considerable, but the ...

AI Technical Summary

Problems solved by technology

After the establishment of the boundary layer theory, after years of development, drag reduction methods can be roughly divided into four categories according to different ways to reduce viscous drag. 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 technology and technological measures to realize the replacement of viscous fluids with very different viscosities and specific gravity at all boundaries are still difficult to completely solve, and it is difficult to promote. At present, it is mainly used in the fields of 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 through air suction and other measures to reduce viscous resistance. There are many researches and applications in the field of outflow such as aviation, which have been discussed in detail in a large number of monographs , its drag reduction effect is limited

The third type injects polymer dilute liquid into the wall area to reduce drag, which can be used for drag reduction of crude oil, water and other fluids, but polymers are expensive and prone to failure when subjected to shear force, and the drag reduction effect is limited

The fourth category is to use appropriate boundary materials (elastic materials) to make the boundary fully compliant, so that it is easy to generate dynamic responses, and vibrate with the TS wave fluctuation of the laminar boundary layer, which is developed by bionics research. However, its drag reduction effect is still limited

However, the reduction of shape resistance still basically stays in the aspect of exploring the streamlined line of the object. There is also a method to arrange a channel inside the drag-reduced object to connect the head and tail, so that the fluid can be discharged from the front to the rear through the channel, reducing the front and rear ends. The pressure difference reduces the viscous pressure resistance, but the channel friction resistance is relatively large, which affects the drag reduction effect

Another notable method is to let the boundary surface of the object move with the fluid movement. This early discovery has been verified by intuitive experiments, but later this method has not been widely used and is almost forgotten by people. And the drag reduction effect of its technical scheme is limited, so it has not attracted attention so far

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