Study on Numerical Instability and Accuracy of Large Eddy Simulation for Complex Turbulent Flows

点击翻译按钮获取中文摘要

Large Eddy Simulation (LES) is investigated as a generally accurate method for the complex turbulent flows where the statistical models are difficult to apply. However, LES was still difficult to perform accurately and effectively enough in the application to engineering problems. Here it is important to develop both appropriate numerical method and turbulence model to perform the LES in accurate and stable computation. This research investigated these numerical method for LES in the following points ; i) Numerical formulation of dynamic SGS model and its validation, ii) validation of SGS models in the micro-scale structure analysis using the numerical results by direct simulation, iii) study on the influence of inlet fluctuate condition and its validation in the annular jet flows, iv) proposal of numerical model for suppressing instability of LES and its validation in separated turbulent flows. These analysis and proposals were introduced into practical simulations of complex turbulent flows such as spray combustion, lift-up barrner flame and gasturbine combustor flows. Pulsating flow simulation in brain artery was also analyzed the above technique.