The most common method to determine the coefficient of Smagorinsky model now is to employ the Germano identity,however it is too complex and expensive in numerical calculation. In this letter we propose a new dynamic ...The most common method to determine the coefficient of Smagorinsky model now is to employ the Germano identity,however it is too complex and expensive in numerical calculation. In this letter we propose a new dynamic formula for determining the coefficient,which is based on the Kolmogorov equation of filtered velocity in physical space.The simplified formula is quite easy to implement in calculation.It is then verified in both homogeneous isotropic turbulence and wall-bounded turbulence by A Priori and A Posteriori tests.展开更多
We review the previous attempts of rational subgrid-scale （SGS） modelling by employing theKolmogorov equation of filtered quantities. Aiming at explaining and solving the underlyingproblems in these models, we ...We review the previous attempts of rational subgrid-scale （SGS） modelling by employing theKolmogorov equation of filtered quantities. Aiming at explaining and solving the underlyingproblems in these models, we also introduce the recent methodological investigations for therational SGS modelling technique by defining the terms of assumption and restriction. Thesemethodological works are expected to provide instructive criterions for not only the rational SGSmodelling, but also other types of SGS modelling practices.展开更多
基于A. S. Gurvich等人所提出的非柯尔莫哥洛夫湍流功率谱密度模型，推导了弱起伏条件下的到达角起伏方差，得到了一个解析的结果；然后，利用该结果分析了对流层柯尔莫哥洛夫湍流和平流层非柯尔莫哥洛夫湍流对星光到达角起伏的联合影...基于A. S. Gurvich等人所提出的非柯尔莫哥洛夫湍流功率谱密度模型，推导了弱起伏条件下的到达角起伏方差，得到了一个解析的结果；然后，利用该结果分析了对流层柯尔莫哥洛夫湍流和平流层非柯尔莫哥洛夫湍流对星光到达角起伏的联合影响。结果表明：星光到达角起伏主要是由对流层柯尔莫哥洛夫湍流决定；对于不同的接收孔径，到达角起伏5%~14%是由平流层非柯尔莫哥洛夫湍流引起的。此外，非柯尔莫哥洛夫湍流对到达角起伏还取决于接收孔径、湍流外尺度及非柯尔莫哥洛夫湍流起伏强度。展开更多
文摘The most common method to determine the coefficient of Smagorinsky model now is to employ the Germano identity,however it is too complex and expensive in numerical calculation. In this letter we propose a new dynamic formula for determining the coefficient,which is based on the Kolmogorov equation of filtered velocity in physical space.The simplified formula is quite easy to implement in calculation.It is then verified in both homogeneous isotropic turbulence and wall-bounded turbulence by A Priori and A Posteriori tests.
基金supported by the National Natural Science Foundation of China (11772032, 11572025, and 51420105008)
文摘We review the previous attempts of rational subgrid-scale （SGS） modelling by employing theKolmogorov equation of filtered quantities. Aiming at explaining and solving the underlyingproblems in these models, we also introduce the recent methodological investigations for therational SGS modelling technique by defining the terms of assumption and restriction. Thesemethodological works are expected to provide instructive criterions for not only the rational SGSmodelling, but also other types of SGS modelling practices.
文摘基于A. S. Gurvich等人所提出的非柯尔莫哥洛夫湍流功率谱密度模型，推导了弱起伏条件下的到达角起伏方差，得到了一个解析的结果；然后，利用该结果分析了对流层柯尔莫哥洛夫湍流和平流层非柯尔莫哥洛夫湍流对星光到达角起伏的联合影响。结果表明：星光到达角起伏主要是由对流层柯尔莫哥洛夫湍流决定；对于不同的接收孔径，到达角起伏5%~14%是由平流层非柯尔莫哥洛夫湍流引起的。此外，非柯尔莫哥洛夫湍流对到达角起伏还取决于接收孔径、湍流外尺度及非柯尔莫哥洛夫湍流起伏强度。
