共轴对转螺旋桨的非定常气动干扰

Unsteady aerodynamic interactions of contra rotating propeller

为优化共轴对转螺旋桨的气动性能,研究前后桨之间复杂的非定常气动干扰,使用非定常雷诺平均Navier-Stokes(URANS)方程的数值模拟方法,以及滑移网格技术,对6×6构型的共轴对转螺旋桨进行了三维非定常气动干扰计算,获得了共轴对转螺旋桨的气动特性变化规律,并给出了优化气动外形及运行控制的建议。计算结果表明:来流马赫数为0.38的情况下,由于非定常气动干扰导致的整个共轴对转螺旋桨的拉力系数和功率系数的脉动幅值为1.5%左右,推进效率的脉动幅值在0.1%左右。一个旋转周期内,前后桨均出现了12次周期波动,后桨由于能够吸收一部分前桨产生的切向滑流能量,推进效率比前桨更高一些,而且能够提高整个桨的效率。另外通过压力系数以及轴向速度的径向分布情况看,70%左右的桨半径位置上非定常气动干扰强度相对较大。

In order to optimize the aerodynamic performance of a contra rotating propeller and study the complex unsteady aerodynamic interactions between two propellers of the contra rotating propeller,the unsteady Reynolds-averaged Navier-Stokes(URANS)numerical simulation method and sliding mesh technique were implemented.The three-dimensional unsteady aerodynamic interaction of a 6×6 contra rotating propeller configurations was calculated,which indicated the variation of aerodynamic performance of the contra rotating propeller.Furthermore,the suggestions for optimizing the aerodynamic layout and operation control method were given.The simulation results showed that the fluctuation of the thrust coefficient and power coefficient of the overall contra rotating propeller was about 1.5%and the fluctuation of the propulsion efficiency was about 0.1%due to the unsteady aerodynamic interference at the cruise Mach number 0.38.There were 12 periodic fluctuations in both the front and aft propellers during one rotation.Because the aft propeller of contra rotating propeller can take advantage of the tangential slipstream energy of the front one,it had much higher propulsion efficiency than that of the front propeller,and the efficiency of the overall rotor can be improved too.In addition,according to the distribution of pressure coefficient and axial velocity,the intensity of unsteady aerodynamic interaction was relatively large at 70%of rotor radius.