The paper briefly reviews the progress in turbulence research in the 20th century and a number of issues are addressed based on achievements.The mod- ern theory of Navier-Stokes equation provides the theoretical basis...The paper briefly reviews the progress in turbulence research in the 20th century and a number of issues are addressed based on achievements.The mod- ern theory of Navier-Stokes equation provides the theoretical basis for the develop- ment of turbulence research.The significance and bottle neck of DNS and the physical experiment in exploring turbulent flows are analyzed.The active manipulation of tur- bulence is directly guided by the knowledge of large-scale coherent structures.The existing problems in the large-eddy simulation are also pointed out.Scalar turbu- lence,which behaves quite different from fluid turbulence in many aspects,has drawn much attention in recent years.Besides the analysis of the difficulties in turbulence research,a number of examples are also presented to show how to use modern theory, computer and high technology to explore the nature of turbulence.展开更多
Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, foc...Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, focusing on evaluating how well these models predict the effects of small scales. The article discusses a priori and a posteriori test results. Other nonlinear models are briefly discussed, and future prospects are noted.展开更多
The turbulent passive scalar fluxes were studied by separately considering the contributions of small eddy motions and large eddy ones. Explicit algebraic approximation was achieved for both small eddy and large e...The turbulent passive scalar fluxes were studied by separately considering the contributions of small eddy motions and large eddy ones. Explicit algebraic approximation was achieved for both small eddy and large eddy scalar fluxes. Especially, the large eddy scalar flux was modelled with complex diffusivity. The singular difficulties in usual algebraic scalar models, do not occur any more in this model. In addition, this new model provides a new way to reasonably describe the negative transport phenomena appearing in asymmetric turbulent flows.展开更多
基金The project supported by the National Natural Science Foundation of China (NSFC) (19572041 and 19732005)
文摘The paper briefly reviews the progress in turbulence research in the 20th century and a number of issues are addressed based on achievements.The mod- ern theory of Navier-Stokes equation provides the theoretical basis for the develop- ment of turbulence research.The significance and bottle neck of DNS and the physical experiment in exploring turbulent flows are analyzed.The active manipulation of tur- bulence is directly guided by the knowledge of large-scale coherent structures.The existing problems in the large-eddy simulation are also pointed out.Scalar turbu- lence,which behaves quite different from fluid turbulence in many aspects,has drawn much attention in recent years.Besides the analysis of the difficulties in turbulence research,a number of examples are also presented to show how to use modern theory, computer and high technology to explore the nature of turbulence.
基金supported by the startup funding provided by HUST
文摘Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, focusing on evaluating how well these models predict the effects of small scales. The article discusses a priori and a posteriori test results. Other nonlinear models are briefly discussed, and future prospects are noted.
基金The project supported by the National Natural Science Foundation of China(Grant No.1 9872042)
文摘The turbulent passive scalar fluxes were studied by separately considering the contributions of small eddy motions and large eddy ones. Explicit algebraic approximation was achieved for both small eddy and large eddy scalar fluxes. Especially, the large eddy scalar flux was modelled with complex diffusivity. The singular difficulties in usual algebraic scalar models, do not occur any more in this model. In addition, this new model provides a new way to reasonably describe the negative transport phenomena appearing in asymmetric turbulent flows.
