基于实验设计方法的高超声速飞机前缘型线优化分析

为探索前缘线变化对吸气式高超声速飞机气动性能的影响,基于一种旁侧进气布局翼身融合体构型,在飞行马赫数6,攻角4°和高度26 km的巡航飞行条件下,结合运用增量修正参数化设计方法、均匀实验设计方法和计算流体力学模拟,分析了飞行器前缘型线与其升阻力系数及纵向压心等性能参数间的关系.计算结果表明,前缘线形状对飞行器升阻力系数明显高于其对纵向压心影响,设计空间范围内升力系数变化约21.3%,阻力系数变化约31.8%,升阻比变化范围约10.63%,但相对压心变化范围仅为3.87%.在此基础上,通过对典型构型物面压力分布进行分析,发现前缘线形状适当弯曲可利用飞行器下表面侧壁压缩产生的高压气流,利用二者的耦合效应使飞行器获得额外的升力增量. 

OPTIMIZATION AND ANALYSIS OF THE LEADING EDGE SHAPE FOR HYPERSONIC AIRPLANES BASED ON DOE METHODS

By taking a Blend-Wing-Body configuration with dual flanking inlets layout as the baseline, an aerodynamic shape optimization study for the leading edge of the vehicle is carried out.An increment-based method is developed to parameterize the leading edge, and the uniform design method is taken as the optimization driver.Totally 31 configurations with different leading edge shapes are generated, and then the aerodynamic performance of all configurations are evaluated by computational fluid dynamic simulation in the cruising conditions of Mach 6, flight altitude 26 km, and flight angle of attack 4°.Numerical results show that the relative variations of the lift and the drag coefficients in whole design space are 21.3% and 31.8%, respectively.Consequently, the relative variation of the lift-to-drag ratio is about 10.63%.In contrast, the maximal value of the relative position transition for the longitudinal pressure center is only 3.87%.Besides, the results also indicate that there is a proportional relationship between the vertical project area and the lift or drag coefficients. Finally, the effect of the leading edge deformation on the aerodynamic characteristics is analyzed on the basis of the results, and some primary rules are concluded.A concave shape of the leading edge is benefit to the improvement of the lift-to-drag ratio, while a convex one leads to a large lift coefficient.