摘要
为了揭示超低马赫数空腔流诱发自激振荡的机理,通过引入弱可压缩流体模型并采用大涡模拟对空腔内的瞬态流场和压力脉动进行了计算。将计算获得的腔内压力脉动与低噪声风洞测试结果进行了对比,以验证计算方法的可靠性。结果表明:弱可压缩流模型的大涡模拟能较为准确地预测超低马赫数空腔流自激振荡的频率与幅值;频率分布显示振荡具有准谐振的特点;空腔内的流场结构和开口处涡的运动表明自激振荡的产生机理为空腔前缘的涡旋脱落后击打在空腔的后缘,产生压力回弹,回弹的压力波传到上游进一步加剧了涡旋的脱落。
In order to reveal the mechanism of self-oscillation evoked by cavity flow at ultra low Mach number, the instantaneous flow field and pressure fluctuation inside the cavity were computed by large eddy simulation based on the weakly compressible fluid model. To validate the computational scheme, the pressure fluctuation inside the cavity obtained by numerical simulation was compared with that by low noise wind tunnel measurement. The results show that the large eddy simulation for weakly compressible fluid model can accurately predict the frequency and amplitude of the self-oscillation at ultra low Mach number. The frequency distribution reveals that the self-oscillation is quasi-harmonic. The flow field structure inside the cavity and the vortex motion along the opening reveal the mechanism of self-oscillation, that is, vortex shedding from the leading edge of cavity will hit the trailing edge of the cavity, then a pressure rebound will appear, finally, the rebound pressure wave will intensify the vortex shedding.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2015年第7期121-126,共6页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51305312)
中央高校基本科研业务费专项资金项目(WUT142207005
2012-IV-068)
现代汽车零部件技术湖北省重点实验室开放基金项目(2012-07)
汽车零部件先进制造技术教育部重点实验室开放基金项目(2013-04)
关键词
汽车工程
空腔流
弱可压缩流模型
大涡模拟
automotive engineering
cavity flow
weakly compressible fluid model
large eddy simulation
