Turbulent Cascades II
Turbulent Cascades II
复制标题
湍流瀑布 II
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Godeferd Fabien
中科院分区：
文献类型：
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作者：
Mikhael Gorokhovski;Godeferd Fabien
螺旋度的衰减及其对动能的影响进行了分析，在非常大的雷诺数均匀各向同性湍流缺乏镜像对称，使用涡阻尼准正常马尔可夫封闭。螺旋度的理论时间衰减指数的推导和评估数值。除了最初众所周知的减慢非线性传输，它进一步表明，螺旋度略有加速巴彻勒湍流动能的衰减，因为它减少了k4的反向传输，这是证明了使用非局部扩展分析。最后，不同于Batchelor湍流的动能谱，螺旋谱的大涡的持久性得到了验证。a. Briard（B）Sorbonne Universités，UPMC Univ巴黎06，CNRS，UMR 7190，d'Alembert，75005巴黎，法国电子邮件：antoine.briard92@www.example.com T. Gomez Université里尔Nord de France，59000，里尔，France © Springer Nature Switzerland AG 2019 M. Gorokhovski和F. S. Godeferd（eds.），湍流叶栅II，ERCOFTAC系列26，www.example.com 3
The decay of helicity and its impact on kinetic energy is analyzed at very large Reynolds numbers in homogeneous isotropic turbulence lacking mirror symmetry, using the Eddy-Damped Quasi-Normal Markovian closure. A theoretical time decay exponent for helicity is derived and assessed numerically. In addition to the initial well-known slowing down of non-linear transfers, it is further shown that helicity slightly accelerates the decay of kinetic energy in Batchelor turbulence, because it decreases the k4 back transfers, which is proved analytically using nonlocal expansions. Finally, unlike the kinetic energy spectrum in Batchelor turbulence, the permanence of large eddies is verified for the helical spectrum. A. Briard (B) Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7190, d’Alembert, 75005 Paris, France e-mail: antoine.briard92@gmail.com T. Gomez Université Lille Nord de France, 59000, Lille, France © Springer Nature Switzerland AG 2019 M. Gorokhovski and F. S. Godeferd (eds.), Turbulent Cascades II, ERCOFTAC Series 26, https://doi.org/10.1007/978-3-030-12547-9_1 3