摘要
采用共振三波的一个周期作为湍流边界层近壁区相干结构的初值 ,用直接数值模拟方法对有压力梯度 ,包括定常压力梯度和变压力梯度作用下相干结构的演化进行了研究 ,得出其各种特性的变化与实验观测到的结果一致。压力梯度对相干结构初始扰动波的选择以及演化过程都起作用 ,相比之下对前者的作用更大。条纹结构和流向涡之间有某种内在的紧密的联系 ,可能是产生流向涡的起因。
By using the method of direct numerical simulation, the coherent structures in the wall region of a turbulent boundary layer with either steady or changing pressure gradients were studied. Initial values of the coherent structures in the wall region were obtained on the basis of the idea of resonant triad in the theory of hydrodynamic stability. It was found that the results of DNS match with those of experiments very well in many aspects. Pressure gradients have much more effect on choosing preliminary waves than on evaluating of the coherent structures. The longitudinal vortices probably result from the streak lines.
出处
《中国工程科学》
2002年第11期50-56,共7页
Strategic Study of CAE
基金
国家自然科学基金资助项目 ( 10 172 0 16 )
国家重点研究发展规划资助项目 ( 19990 2 2 30 5 )
国家自然科学基金重点基金资助项目 ( 50 136 0 10 )
关键词
演化
相干结构
湍流边界层
压力梯度
数值模拟
流体力学
coherent structures
turbulent boundary layer
pressure gradients
direct numerical simulation(DNS)
