Large eddy simulation of mixed convection in transient laminar and turbulent flows in a square cavity

• Main Authors: SHEN,Fu-Ti, 沈富第
• Other Authors: Yang ,Yi - Lung
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/09050907356807893304

碩士 === 中華大學 === 機械工程學系碩士班 === 100 === This work presents large eddy simulation of mixed convection in transient, two-dimensional laminar and turbulent flows in a square cavity.The Smagorinsky model is employed for the sub-grid treatment. The simulations are based on the finite volume solution of the conservation equations, and are presented for Reynolds and Richardson numbers ranging from 400 to 10,000 and from 0.1 to 0.44, respectively. The agreement in solutions for the transient laminar flow is very well with those in the literature. Results for the development of turbulent flow and final turbulent fluctuation are compared well the previous work. In general, the results show a 21% increase of heat transfer from unstable stratification to stable one. The power spectral density of velocity and pressure moves to high frequency regime with significant resonant by the base frequency. The power spectral density of temperature dominates within the base frequency. The results indicate that the temperature and the velocity components fluctuate separately.