学术
摘 要:
使用高精度的有限差分格式直接数值模拟了Mach数等于0.8和1.3两种条件下的槽道湍流。根据数值模拟得到的速度差的概率密度分布,计算了两个方向的速度结构函数的相对标度指数。与不可压的标度指数的对比表明在y^＋=20附 近和槽道中心区,压缩性对标度律的影响很小;而在粘性底层（y^＋=5.5）和对数区内 （y^＋≈120）,压缩性对标度指数有显著影响。对六阶标度指数沿壁面距离变化的进一步分析表明,槽道可以分为4个不同行为区,在不同行为区间歇性的变化规律具有不同的特征,其中最大雷诺剪应力所在的那个区域间歇性最强。[著者文摘]
文章出处:
《北京大学学报：自然科学版》-2007年43卷3期 -307-311页
栏目信息:
分 类 号:
Numerical Studies of Scaling Exponents in Compressible Wall-Bounded Turbulence
HU Kaiheng ,CHEN Kai, SHE Zhensu （State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing , 100871 ）
Abstract:
Compressible turbulent channel flows at two Maeh numbers （M = 0.8 and 1.3 ） are simulated by the numerical integration of the Navier-Stokes equations with a high-order compact finite difference scheme. The comparative studies of incompressible and compressible flows indicate that the effect of compressibility on the scaling exponents is small in the region near y^＋= 20 and in the center while it is significant in the viscous sublayer （y^＋ = 5.5） and the log-law region （y^＋≈120）. Further studies on the variation of the relative scaling exponent show that the channel can be divided into four distinct zones according to their scaling behavior： viscous sublayer and lower edge of buffer layer （Ⅰ） ; the outer part of the buffer layer and lower part of log region （Ⅱ） ; the major part of the log region and lower edge of the center region （Ⅲ） ; and finally the other part of the center region （Ⅳ） . The variation of the scaling exponents with the compressibility is the most remarkable in the zone Ⅰ and Ⅲ . Finally, it is found that the most intermittent region exactly coincides with the location of the maximum Reynolds shear stress.[著者文摘]
Key words:
scaling law; direct numeric simulation; compressible channel flow; extended self-similarity
基金资助:
国家自然科学基金（10032020,10225210）资助项目.致谢 感谢北京大学科学与工程计算中心（CCSE）提供了计算资源,感谢中科院力学所的李新亮副研究员和傅德薰研究员为本研究提供的诸多指导和建议,感谢郝鹏程提供了不可压缩槽道湍流的数据.
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