翼身组合体气动力计算研究

A Numerical Method Research on Wing Body Configurations

采用求解Euler方程结合附面层修正的方法在结构网格上对翼身组合体跨音速流场进行了数值模拟。附面层方程的求解应用Whitfield提出的动量积分方程和平均流动能积分方程,为了保持Euler方程求解过程中计算网格的固定性,用加在物面上的溢出速度来模拟附面层效应。针对传统的近场方法计算阻力,计算精度较低、误差较大并且不能给出各阻力分量值的缺点,将基于动量定理的远场方法用于飞机的阻力估算,采用远场法将阻力分解为:粘性阻力,激波阻力,诱导阻力,并对各个分量分别进行了求解,将计算结果与近场法以及风洞实验值做了比较。以DLR-F4翼身组合体为考核算例,对所述方法进行了验证,结果显示远场法的计算结果与风洞实验值吻合的很好。

To compute transonic flows over a complex three dimensional aircraft configuration, a viscous/ inviscid interaction method was developed by coupling an boundary-layer solver with Eluer solver. A blowing velocity approach was used to simulate the displacement effects of boundary layer. To predict the aerodynamic drag, a numerical technique called far-field method was developed that is based on the mo- mentum theorem, in which the total drag is divided into three component drags, i.e. viscous, induced and wave-formed. Consequently, it can provide more physical insight into the drag sources than the often-used surface integral technique. The drag decomposition can be achieved with help of second law of thermody- namics, which implies that entropy increases and total pressure decreases only across shock wave along a streamline of an inviscid non-isentropic flow. This method has been applied to the DLR-F4 wing-body configuration showing results in good agreement with the wind tunnel data.