CAJ | 학술논문

针对返回舱再入过程中需要满足的复杂气动力热条件，在典型高超声速条件下以升阻比和阻力系数为目标，以驻点热流和容积率为约束条件进行返回舱外形多目标优化设计。气动特性分析采用基于三维Navier-Stokes方程和结构网格的计算流体力学数值仿真(CFD)方法，采用Fay-Riddell经验公式计算驻点热流，采用NSGA-II优化算法进行全局寻优，为了增强多目标优化设计的计算效率，利用Kriging代理模型替代CFD计算，并引入改进的EI函数加点策略，大大减少了构建代理模型时所需的样本点数目。优化计算结果表明，代理模型计算结果与CFD计算结果误差可以控制在7％以内，基于代理模型技术的优化过程可以节省95％以上的计算开销。因此，该方法能够较好地满足初步设计的要求，为返回舱外形优化提供有益的借鉴。
침대반회창재입과정중수요만족적복잡기동력열조건，재전형고초성속조건하이승조비화조력계수위목표，이주점열류화용적솔위약속조건진행반회창외형다목표우화설계。기동특성분석채용기우삼유Navier-Stokes방정화결구망격적계산류체역학수치방진(CFD)방법，채용Fay-Riddell경험공식계산주점열류，채용NSGA-II우화산법진행전국심우，위료증강다목표우화설계적계산효솔，이용Kriging대리모형체대CFD계산，병인입개진적EI함수가점책략，대대감소료구건대리모형시소수적양본점수목。우화계산결과표명，대리모형계산결과여CFD계산결과오차가이공제재7％이내，기우대리모형기술적우화과정가이절성95％이상적계산개소。인차，해방법능구교호지만족초보설계적요구，위반회창외형우화제공유익적차감。
This paper investigates the multi-object optimization design of reentry capsule configuration under typical hypersonic conditions, aiming at satisfying the complex aerodynamic heating conditions that arise during reentry, where the lift-drag ratio and drag coefficient are the two objects with the constraints of the stagnation point heat flux and volume efficiency. The NSGA-II is utilized to perform the multi-object configu-ration optimization. For a given set of configuration parameters generated by the NSGA-II, the three-dimension Navier-Stokes(NS) equation and structure grid Computational Fluid Dynamics(CFD) method are used to com-pute the lift-drag ratio and drag coefficient, and the Fay-Riddell empirical formula is used to estimate stagna-tion point heat flux. To improve the computational efficiency, the Kriging surrogate model, with a modified Expected Improvement(EI) sampling strategy to reduce the sample number, is used to replace the CFD compu-tation during the optimization. The optimized results indicate that the Kriging surrogate model can reduce about 95% computational cost and the resultant errors are within 7% when compared with the CFD. Thus, the pro-posed method can be used as a preliminary design tool for reentry capsule configuration optimization.