A bionic jet model based on the feature of shark gill was established for the characteristics of flow field on the bionic jet surface. The drag reduction characteristics and drag reduction mechanisms of bionic jet flow based on shark gill were studied using numerical simulation method at the main flow field velocity of 3 m/s and the jet velocity of 0. 02-1 m/s. The results show that: the bionic jet flow based on shark gill has a drag reduction effect when the jet velocity u is more than 0. 1 m/s,and the drag reduction rate increases with jet velocity. The bionic jet flow based on shark gill affects the drag reduction characteristics of model by changing the frictional resistance and pressure drag. The mechanism of bionic jet flow influencing on frictional resistance is that the thickness of viscous sublayer at the downstream of jet outlet increases and the velocity gradient reduces. And a reverse eddy forms,which makes the flow field have a stable large vortex structure and reduce the influence of turbulent fluctuation on the wall. The mechanism of bionic jet flow influencing on pressure drag is that the jet velocity,as an additional power,inhibits the differential pressure resistance,resulting in its decline.%针对鲨鱼鳃部射流表面流场特性,建立了基于鲨鱼鳃部特征的仿生射流模型,采用数值模拟方法,在主流场入口速度为3 m/s、射流速度为0.02 ～1 m/s条件下,研究仿鲨鱼鳃部射流的减阻特性、分析其减阻机理.研究结果表明:当射流速度u＞0.1 m/s时,仿鲨鱼鳃部射流具有减阻效果,且减阻率随射流速度增大而增大.仿鲨鱼鳃部射流通过影响摩擦阻力和压差阻力改变减阻特性.仿鲨鱼鳃部射流对摩擦阻力的影响机理为:射流出口下游流场黏性底层增厚、速度梯度降低；同时形成反向旋涡,使流场存在稳定的大涡结构,降低了湍流脉动对壁面的作用.对压差阻力的影响机理为:射流速度作为一种附加动力,对压差阻力产生抑制效应,导致了模型压差阻力的下降.
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