鲨鱼沟槽表皮减阻机理的仿真研究

Simulation Studies on Drag Reduction Mechanism of Shark Riblets Surface

通过对鲨鱼沟槽表面特殊流场的数值仿真研究,探讨了沟槽表面存在减阻效果的内在机理。针对沟槽表面流场的特点,在数值计算过程中对其计算域、计算网格及其流动参数进行了合理化的处理,并尝试将力学相似原理运用于沟槽表面流场的数值仿真。仿真结果表明,沟槽表面与顺流的"反向旋转涡对"相互作用,产生"二次涡",削弱了"反向旋转涡对"的强度,进而抑制了低速条带的形成和发展,从而降低湍流猝发强度,实现湍流减阻。

Through the numerical simulation investigation, the turbulent drag redaction mechanism above shark riblets surface was explored. In allusion to the characteristic of riblets surface, the computation region, grids and flow parameters were dealt with reasonably, and mechanic similarity principle was brought forwards into fluid field numerical simulation. The results of simulation show that a series of ＂second-vortex＂ are produced when streamwise ＂reverse-vortices＂ are effected by riblets. They weaken intensities of ＂reverse-vortices＂, and restrain the productions and developments of low-flow strips, so turbulent drag reduction is obtained.