一种高效的舵面偏转气动力计算方法研究

An Efficient Approach for Computation of Control Surface Deflection Effect

飞机设计过程中需要掌握各种舵面偏转气动特性。采用计算流体力学(CFD)技术计算舵面偏转气动力时,不同的舵面偏转角度通常需要生成不同的网格、网格变形或重构,这一过程需要耗费大量时间。一种简化的计算方法是蒸腾边界方法,通过在舵面的边界条件中增加一个法向扰动速度以模拟舵面偏转,从而可以在不进行网格变形或重新生成网格的情况下计算不同舵面偏转角度下的气动力系数。本文采用跨声速巡航标模(TCR)鸭翼偏转构型验证蒸腾边界方法计算舵面偏转气动力的有效性,迎角范围为-6°~10°,鸭翼偏转角范围为-15°~10°。通过对网格变形和蒸腾边界两种方法进行气动力计算对比,结果显示,蒸腾边界方法可以在网格保持不变的情况下获得有效的气动力计算数据,两种方法多数工况的计算结果基本一致,只有在迎角和舵偏角产生叠加效应使得舵面相对迎角较大的工况下,两种方法的计算结果存在一定差异。

Computing the aerodynamics of various control surface deflect configurations with CFD method generally needs to generate a new computational mesh, or deform, or reconstruct the mesh for each configuration, which is quite tedious and time consuming. An option method is to use transpiration boundary condition to simulate the movement of control surface deflection by adding a normal grid velocity on the boundary. This approach needs no extra mesh operations, which makes the large batch of computation tasks quite efficient. There is a lack of research on the applicability of transpiration boundary condition method for different angle of attack of aircraft and various control surface deflection angles. In this paper, Transonic Cruiser(TCR) model is selected to study the effectiveness of transpiration boundary condition method for the simulation of canard deflection effect. The angles of attack studied are from-6° to 10°, and canard deflect angles are from-15° to 10°. The computations are carried out using inviscid Euler flow equations. It is shown that the computed normal force and pitch moment coefficients using transpiration boundary condition method and mesh regeneration method match each other if the canard relative angle of attack is not so large. The computational results are also compared with wind tunnel test data, the agreement of normal force coefficients are acceptable, and the agreement of pitch moment coefficients are reasonable if the canard relative angle of attack is not so large. The comparison of aerodynamic coefficient delta value due to canard deflections further confirmed the effectiveness of the transpiration boundary condition method.