基于遗传算法的旋翼翼型综合气动优化设计

结合直升机飞行特性及旋翼工作气动环境,提出了适用于中型运输直升机旋翼翼型优化设计的目标函数及约束条件.在此基础上采用遗传算法,以"黑鹰"(UH-60A)直升机旋翼翼型SC1095为基础翼型,进行多目标、多状态以及多约束条件下的旋翼翼型优化设计.优化翼型同SC1095翼型相比弯度稍大,最大厚度略有增加.结果表明:优化翼型气动力特性在满足约束条件的情况下,零升力矩系数减小了57.2%,最大升力系数增加了3.7%,阻力系数减小了7.5%.同时,非定常动态失速状态下的气动特性也有一定的改善,阻力系数和力矩系数的发散范围均有明显的减小.此外,悬停状态计算结果表明:采用优化翼型构成的旋翼与SC1095旋翼相比,具有更高的悬停效率及更低的力矩系数. 

Synthetical optimization design of rotor airfoil by genetic algorithm

According to the flight characteristics of helicopter and working environments of rotor, a group of airfoil design states, objective functions and constraint conditions suitable to the medium utility helicopter were proposed. The airfoil optimization was accomplished at multi-objective, multi-state and multi-constrain based on the classical rotor airfoil SC1095 used in "black hawk" helicopter (UH-60A) by genetic algorithm. The optimized rotor airfoil had larger camber and maximum thickness compared with the SC1095 airfoil. Results demonstrate that the pitching moment coefficient decreases by 57.2%, maximum lift coefficient increases by 3.7% and drag coefficient decreases by 7.5%. Meanwhile, there are some improvements of optimized airfoil aerodynamic characteristics under unsteady conditions compared with SC1095 airfoil. The areas of drag divergence and moment divergence of optimized airfoil decrease. After that, a rotor blade is constructed by using the optimized airfoil,results indicate that the FM (figure of merit) is increased and blade pitching moment coefficient is decreased compared with the baseline blade composed by SC1095 airfoil.