为减小高速列车气动阻力,根据仿生非光滑理论,以鲨鱼体表为仿生对象,建立仿生非光滑沟槽的几何外形,采用经风洞试验验证的数值模拟方法,开展仿生非光滑沟槽的减阻效果研究。计算结果表明:仿生非光滑沟槽的存在可以阻碍由湍流运动引起的瞬时横向流动的发生,降低湍流与壁面之间的摩擦阻力;沟槽顶端区域的摩擦阻力系数接近于光滑壁面的摩擦阻力系数,而其余大部分区域内的摩擦阻力系数则小于光滑壁面的摩擦阻力系数;在不同的气流速度(60~160m/s)下,沟槽壁面的阻力系数均小于光滑壁面的阻力系数,仿生非光滑沟槽的减阻率可达6%以上。
In order to reduce the aerodynamic drag of the high-speed train,the geometry configuration of the bionic non-smooth riblets as an idealized model of shark skin was set up based on the bionic non-smooth theo-ry.And by means of the computational model verified with the wind tunnel test data,study on drag reduction of the bionic non-smooth riblets was carried out.The computational results show that the existence of the bionic non-smooth riblets impedes the generation of the instantaneous lateral flow caused by the turbulence,and re-duces the friction drag between the turbulence and the wall.The frictional drag coefficient in the top domain of the riblets is close to that of the smooth wall,while the frictional drag coefficient in the rest domain of the riblets is smaller than that of the smooth wall.For the different flow velocities(60 m/s~160 m/s),the drag coefficient of the non-smooth riblets wall is smaller than that of the smooth wall.Moreover,the drag reduction rate can de-crease by more than 6% for the bionic non-smooth riblets.