| 摘要 |
A nonsmooth surface of an object in a fluid flowstream permits a reduction of turbulent drag. The surface shape is designed to approximate a minimal surface and satisfies the equation (Vx NABLA ) NABLA PHI =0, where V is the relative velocity between the fluid and the surface, NABLA PHI is the velocity of the strain tensor. The improved surface shape may be an array of diamond shaped elements having an airfoil like diagonal along the streamline, or it may be a series of wavelets juxtaposed to one another. The specific shape of the various types of elements to be used on the surface is selected based upon the acceleration or deceleration of the fluid at the particular position on the surface, as well as the intensity of the turbulence at that position.
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