直升机机身气动外形的低阻优化设计

直升机机身阻力是飞行阻力的主要来源之一,通过对机身外形的优化设计,能够实现直升机的高效低阻飞行.首先,把机身划分为头部、中段和尾梁三段,对其外形轮廓线进行CST参数化表示;其次,采用拉丁超立方法选取试验设计样本点,计算各样本点的阻力系数,构造Kriging代理模型,估计模型预测的精度;最后,选用序列二次规划算法对其进行优化,并对优化后的机身模型进行了风洞试验.通过计算分析可知:所建立的Kriing代理模型能够精确预测阻力系数值,优化后得到了机身的设计参数;机身阻力系数减小了15.3％,理论值与试验值吻合良好.

Low-drag optimization design of aerodynamic shape for helicopter fuselage

Helicopter fuselage drag was one of the flight drag source,high efficient and low drag flight of helicopter was realized through the optimization design of the fuselage shape.First,fuselage was divided into three sections:fuselage head,middle and tail beam,outline profile was parameterized by class shape transformation(CST).Secondly,the Latin hypercube method was used to select experimental design sample points,drag coefficients of sample points was calculated,Kriging agent model was built and precision of agent model prediction was estimated.Finally,the sequential quadratic programming algorithm was used for its optimization,and wind tunnel test was conducted for optimized fuselage model.Through calculation and analysis,Kriging agent model can accurately predict drag coefficient value,get the fuselage design parameters after optimization,and the fuselage drag coefficient decreases by 15.3％,theoretical values are consistent with experimental values.