摘要
对超声速冷流条件下用于超燃冲压发动机的凹腔火焰稳定器的质量交换特性进行研究．采用混合RANS／LES方法对非定常流场进行数值模拟,考虑了凹腔的长深比和后缘角度两个关键参数．计算得到了凹腔剪切层拟序结构的演化过程．对凹腔压力振荡历程进行幅频分析,所得到的频率和理论分析结果及一些计算结果十分吻合．结果表明,凹腔的长深比和后缘倾角对凹腔质量交换过程都有较大的影响．凹腔驻留时间随着长深比的增加而增加．随着后缘倾角减小,长深比较小的凹腔的驻留时间增加,长深比较大的凹腔则完全相反．该计算结果为凹腔设计提供了新认识．
Mass exchange characteristics of cavities for scramjet applications within a supersonic cold flow are investigated. Calculations are carried out using the hybrid RANS/LES method to predict unsteady state flowfields. The key cavity parameters include cavity aft wall angle and cavity length to depth ratio （L/D）. The hybrid model captures the large scale unsteadiness and reveals the evolvement of cavity free shear layer. For pressure fluctuation spectra, the theoretical prediction agrees quite well with some calculated data. The hybrid RANS/LES data suggest that both the cavity shape and the size have a significant effect on the mass exchange processes. Cavities with larger L/D have a longer residence time. For cavities with smaller L/D, the residence time reduces as the aft wall angle decreases. The opposite is true for cavities with larger L/D. These calculated results provide some new insight for cavity flamehoder design.
出处
《力学学报》
EI
CSCD
北大核心
2007年第2期188-194,共7页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(90505009).~~
