a drag-reducing rib

Abstract

The invention provides a novel resistance reducing rib. According to the resistance reducing rib, a cutting edge rib is additionally arranged at the position of a sharp corner of the peak of a traditional rib, the advantages, of the cutting edge rib, of being high in resistance reduction performance and free of the influence of a machining round corner are combined, the machining difficulty is considered, and the structural strength is improved. By reasonably selecting the size parameters, such as the height of the rib, the included angle, the thickness of the cutting edge and the height of the cutting edge, of the cross section of the rub, influencing the flowing structure of a boundary layer, increasing the thickness of a viscous bottom layer and limiting the extension movement of streamwise vortices, the purpose of resistance reduction is achieved, the friction resistance on the surfaces of aircrafts, underwater vehicles and ground transportation vehicles is reduced, and the application prospect is broad.

Description

technical field [0001] The invention relates to an improved rib drag reduction device, which can be applied to aviation, spaceflight, navigation, ground transportation and pipeline internal flow, etc. field. Background technique [0002] The rib technology is derived from the rib structure of shark shield scales. This bionic structure has been proved by a large number of research works to have strong practicability and good drag reduction effect. In the prior art, it is believed that the ribs with drag reduction effect must have sharp peaks and ridges, and there is a certain relationship between the spacing and the low-speed strip spacing, that is, when h + ≤25 and s + ≤30( See figure 1 , h is the rib height, s is the rib spacing, υ is the kinematic viscosity, u τ is the friction velocity, τ w is the wall shear stress, ρ is the density of the fluid medium, and the superscript "+" indicates a dimensionless parameter in the wall unit, the same below), and s + = h + =1...

AI Technical Summary

Problems solved by technology

[0003] The drag reduction effect of the traditional triangular cross-section rib is limited and is easily affected by the fillet of the peak and ridge. Although the blade-shaped rib has a better drag reduction effect and is not affected by the fillet of the rib tip, the rib with such a thin thickness (t=0.02s) Difficult to process, poor structural strength, easy to break in practical application

The above-mentioned rib structure in the prior art severely limits the practical application of rib drag reduction technology

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