平流层飞艇气动外形优化设计:螺旋桨的影响

Shape Optimization of Stratosphere Airship with Propeller

建立综合螺旋桨影响的平流层飞艇气动外形优化设计平台.采用Hicks-Henne型函数法参数化艇身轮廓,发展IDW-TFI混合动网格技术实现变形网格高效生成;基于作用盘理论模拟螺旋桨,建立飞艇流场高效数值求解方法.以LOTTE飞艇作为初始外形,阻力系数最小为目标,飞艇体积作为约束条件,通过NLPQL算法寻优获得最佳艇身设计方案.优化后飞艇的尾部形状较平坦,艇身最大横截面位置前移,气动性能得到明显改善,其阻力系数相对于初始外形降低了26.88%.

A design platform for airship shape optimization with propeller is established with computational fluid dynamics and optimization techniques.Firstly,Hicks-Henne shape functions were used to parameterize hull of the airship.Then,a hybrid dynamic mesh generation method was presented based on inverse distance weighting(IDW)interpolation and transfinite interpolation(TFI).An actuator disk model of propeller was employed to simulate viscous flow around the airship.LOTTE airship was chosen as the initial shape,and drag coefficient was chosen as the objective function.Airship volume was selected as a constraint.The optimized shape based on non-linear programming by quadratic lagrangian(NLPQL)algorithm was obtained.It shows that afterbody shape of the optimized airship is relatively flat and location of the maximum diameter moves forward.Aerodynamic performance of the new shape is significantly improved.Compared with that of the LOTTE hull,drag coefficient of the optimized shape is reduced by 26.88%.