Multiobjective design optimization of the performance for the cavity flameholder in supersonic flows
Multiobjective design optimization of the performance for the cavity flameholder in supersonic flows
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DOI：
10.1016/j.ast.2013.08.009
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发表时间：
2013-10
影响因子：
5.6
通讯作者：
Wei Huang;Jun Liu;Li Yan;Liang Jin
中科院分区：
文献类型：
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作者：
Wei Huang;Jun Liu;Li Yan;Liang Jin
壁装凹腔在超声速流场中对火焰稳定机理有着重要的影响，在超燃冲压发动机流路设计中得到了广泛的应用。但是，凹腔会给发动机带来额外的阻力，并且凹腔内的温度很高。因此，在空腔火焰稳定器的设计过程中，应同时使阻力和温度最小化。本文采用非支配排序遗传算法（NSGA II）和Kriging代理模型，对马赫数为3.0的超音速自由飞行器凹腔稳定器的非反应流场进行了优化，并通过正交表选择了试验工况。同时，将计算结果与Gruber等人的实验结果进行了比较，并利用四种网格尺度进行了网格独立性分析。计算结果表明，用数值方法预测的壁面静压分布与实验数据吻合较好，但沿空腔底面的静压分布沿着存在低估现象。这可能是由湍流模型的不准确性引起的。得到了多目标优化设计结果的Pareto前沿，在阻力和面积加权平均温度之间必须有一个折衷。优化后的阻力随着长深比的增大和后掠角的减小而增大，优化后的面积加权平均温度随着长深比的减小和后掠角的增大而增大。声腔的拖曳力是目前研究中考虑的范围内最小的。但它会产生最强的压力振荡。
The wall-mounted cavity makes a great difference to the flameholding mechanism in the supersonic flow, and it has been widely employed in the design process of the scramjet flowpath. However, the cavity would bring additional drag force to the engine, and the temperature within the cavity is very high. Therefore, both the drag force and the temperature should be minimized in the design process of the cavity flameholder. In the current study, the non-dominated sorting genetic algorithm (NSGA II) coupled with the Kriging surrogate model has been employed to optimize the nonreacting flow field around the cavity flameholder in the supersonic freestream with a Mach number of 3.0, and the test cases have been selected by the orthogonal table. At the same time, the numerical results have been compared with the experimental data obtained by Gruber et al., and four grid scales have been utilized to perform the grid independency analysis as well. The obtained results show that the wall static pressure profiles predicted by the numerical approaches show very reasonable agreement with the experimental data, and the static pressure along the floor face of the cavity is underpredicted. This may be induced by the inaccuracy of the turbulence model. The Pareto front for the multiobjective design optimization results is obtained, and there must be a compromise between the drag force and the area-weighted average temperature. The optimized drag force increases with the increase of the length-to-depth ratio and with the decrease of the swept angle, and the optimized area-weighted average temperature increases with the decrease of the length-to-depth ratio and with the increase of the swept angle. The drag force of the acoustic cavity is the smallest in the range considered in the current study. However, it would generate the strongest pressure oscillation.