面向飞行试验的混合层流机翼优化设计

Optimization design of hybrid laminar flow control wing for flight test

层流减阻技术可大幅减小飞机摩阻,具有重要的应用前景。层流验证机是专为验证层流机翼设计技术研制的一型飞行试验平台,其中混合层流试验段主要用来验证前缘抽吸气对转捩位置的推迟效果。针对混合层流飞行试验首先开展了混合层流试验段设计约束分析和初步方案设计,随后开展了机翼和吊舱、挂架外形的高速气动优化设计。然后在此基础上,研究了不同吸气分布对吸气功率、流量和转捩推迟效果的影响,确定了最佳分布。最后通过风洞试验研究了最终优化构型的转捩特性。研究结果表明:优化后的混合层流试验段具有良好的高速气动特性,同时在设计点能验证前缘抽吸气对横流不稳定性的转捩抑制效果;折中吸气分布能保证吸气区大部分区域的吸气效果,并能降低吸气功率和流量。所得研究结果对混合层流机翼外形、吸气策略优化设计具有借鉴意义。

Drag reduction by the laminar flow control technology can significantly reduce aircraft friction and thus exhibits important application prospects. Laminar X-plane is a flight test platform designed to verify the laminar wing design technology. The hybrid laminar flow test section is mainly used to verify the delay effect of the leading-edge suction on the transition position. For the hybrid laminar flow wing, the design constraint analysis and preliminary design of the hybrid laminar flow test section are first conducted, and the high-speed aerodynamic optimization design of the wing, pod and pylon shape is then carried out. On this basis, the effects of different suction distributions on suction power, flow rate and transition delay are studied, and the optimal distribution is determined. Finally, the transition characteristics of the final optimized configuration are examined through numerical calculation and wind tunnel tests. The results show that the optimized hybrid laminar flow test section has good aerodynamic characteristics, and the transition suppression effect of the leading-edge suction on the crossflow instability wave can be verified at the design point. The compromised suction distribution can ensure the suction effect in most areas of the suction zone and reduce the suction power and flow rate. This study has reference significance for the optimization design of the hybrid laminar wing shape and suction strategy.