Supersonic Nozzle Optimization Design with Spline Curves Fitting the Nozzle Profiles

基于样条曲线描述的超声速喷管型面优化设计

Facility Design and Instrumentation Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China

Received: 1 September 2017

Abstract

Supersonic nozzle contour optimization design was applied to 0.6m×0.6m continuous transonic wind tunnel to improve flow quality in the test section. The Mach number root mean square deviation with the design value was chosen as optimization target. And the CFD results were verified with experimental results. Cubic spline curves with the optimal interpolating point distribution scheme were used to fit the nozzle contour. Efficient global optimization based on the Gaussian process surrogate model was used to reduce the times of evaluation. Results indicate that, the optimization framework can generate a supersonic nozzle contour with better flow quality and more accurate Mach number and that the optimal Mach number root mean square deviation is 0.001.

摘要

以试验段流场指标为目标，对0.6 m连续式跨声速风洞喷管型面进行优化设计。将试验段实际轴向马赫数与设计值的均方根误差作为优化目标，提出优化问题并利用试验结果验证了CFD计算。采用三次样条曲线描述喷管型面，并搜寻到最佳插值点分布方案以提高拟合精度；构建基于高斯过程模型的重启优化算法改善梯度算法全局特性的同时减少了气动评估的次数，提高了计算效率。计算结果表明，该优化设计的方法，能够以较小的代价得到流场品质较优和马赫数准度较高的超声速喷管型面曲线，模型区马赫数均方根偏差最优结果可达0.001。