Large Eddy Simulation of Environmental Flows: From the Laboratory-Scale Numerical Experiments Toward Full-Scale Applications

Abstract

Over the last decades, increasing interest has been paid to environmental fluid mechanics (EFM), in relation to land reclamation and the improvement of the quality of air and water on Earth. The continuous increase of the computer performance, in terms of data storage and CPU time, is making more attractive the use of numerical techniques which, some years ago, were confined in the realm of fundamental research. Among them, large eddy simulation (LES) is emerging as a reliable tool to study problems characterized by complex physics and geometry, typical of environmental processes. This paper reports significant examples of research carried out using LES by the research group of industrial and EFM (IE-fluids) of the University of Trieste, Italy, to study processes of interest to EFM. Two main chapters are developed. The first one reports significant results of idealized LES studies where the physics of turbulence is exploited in cases characterized by stratification, rotation, and dispersion processes. In spite of their significance, they are unable to give answer to engineering EFM problems. The second part of the paper describes the efforts devoted by IE-fluids toward the development and use of new-generation, large scale, LES models able to deal with practical problems of interest to EFM. It is easy to imagine that in the following decades the continuous growth of computer power and capability to store and process big datasets will make real-scale LES a de facto standard for the analysis of problems in EFM replacing, to a large extent, the RANS-based techniques used nowadays.