脊状表面航行器模型减阻特性的风洞实验研究

Wind Tunnel Experimental Investigation on the Drag Reduction of Vehicle Model with Riblets Surface

针对航行器提高航程和航速的需要,开展脊状表面湍流边界层减阻的实验和数值仿真研究。在航行器模型的外表面加工具有特定形状、尺寸的脊状结构,导致湍流边界层的流动稳定性增强,壁面摩擦阻力降低。在风洞中对具有光滑表面和脊状表面的航行器模型在不同风速和攻角下进行阻力测试,得到其减阻特性曲线。实验结果表明,具有横向脊状表面的航行器模型在一定来流速度范围内具有很好的减阻效果,实验获得的最大减阻量为23.5%。数值仿真结果则发现,在脊状结构内形成了稳定的"二次涡",边界层内湍动能和湍流猝发强度降低,很好地揭示了减阻机理。

Experimental study and numerical simulation about turbulent boundary layer drag reduction of riblets surface were carried out for increasing voyage and speed of vehicle. Riblets surface on vehicle model can enhance turbulent boundary layer stability and reduce friction drag. Vehicle models with smooth surface and riblets surface were tested respectively at various velocities and attack angles in a wind tunnel. Drag characteristic curves were acquired through tests. Experimental results show that the vehicle models with transverse riblets surface have obvious drag reduction effect under certain velocity range, the maximal drag reduction effect is 23. 5%. Results of simulation indicate that a series of ＂second-vortex＂ are produced in the riblets structure, turbulent kinetic energy and turbulent burst intensities are debased, which reveals reasonably turbulent drag reduction mechanism.