Simulation Of Separated Flows By Large Eddy Simulation

This research is finished on base of NAPA, which is a common used CFD software developed by College of Energy and Power Engineering of NUAA. In order to improve this software, techniques of Large Eddy Simulation and Dual Time-Stepping method are involved. Main points of the work are listed as following:First, Large Eddy Simulation is added in NAPA after analyzing the complicated structure of this software and the development of Large Eddy Simulation. Classical Smagorinsky sub-grid scale model is chosen to calculate sub-grid scale vortex. Technique of Dual Time-stepping Method is involved to solve the problem of unsteady solving, which is rather difficult when unique time-stepping method is used.After that, program for this special purpose is developed in this work. And parallel computing is achieved based on MPI standard database. Additionally, for unsteady flow data need to be saved during the process of simulation, parallel outputs of these data are included in NAPA. Tests for these programs are also taken doubtlessly.This new improved software is used in simulation of 2-D circular cylinder flow. Comparison of the eddy structure between simulation and classical experimental results indicated that this program is well developed. 2-D wing flow at large angle and 3-D circular cylinder flow are also simulated in this research, and the results are acceptable. Some interfaces are reserved during the process of programming for further researching.