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采用extended free-form deformation(EFFD)方法研究了自然层流(natural laminar flow,NLF)短舱的气动外形优化设计方法.使用基于Bernstein基函数的EFFD方法完成了NLF短舱剖面的参数化,利用基于k-εSST(shear stress transport)两方程湍流模型的γ-θ转捩模型进行自然转捩预测,结合EFFD、一种混合动网格方法、Kriging代理模型和改进的粒子群算法(particle swarm optimization,PSO)建立了针对NLF短舱气动外形的优化设计框架.采用该框架分别对通气NLF短舱和带动力NLF短舱进行优化设计.单独通气NLF短舱优化结果的外表面实现48%的层流,阻力系数比初始通气NLF短舱减小了0.0003.带动力NLF短舱的优化结果外表面保持了41%的层流.这些结果表明采用相关技术建立的优化设计框架在NLF短舱设计中具有一定应用价值.
The aerodynamic shape optimization design method of natural laminar flow (NLF) nacelle was studied by using extended free-form deformation (EFFD) method.The parameterization of NLF nacelle profile was completed by EFFD method based on Bernstein basis function Based on the γ-θ transition model of two-equation k-εSST (turbulence model) shear-stress transport model, the natural transition is predicted. Combined with EFFD, a hybrid grid method, Kriging agent model and improved particle swarm optimization , PSO), an optimized design frame for NLF nacelle aerodynamic profile was established.Using this framework, the optimized design of aerated NLF nacelle and driven NLF nacelle were optimized respectively.The outer surface of NLV nacelle optimization results achieved 48% Flow and the drag coefficient is reduced by 0.0003 compared with that of the initial aerated NLF. The optimization result of powered NLF nacelle maintains 41% of the laminar flow on the outer surface.These results show that the optimal design framework established by the related technology is used in the NLF nacelle design Has a certain application value.