난류 파이프 유동내 물질전달에 대한 레이놀즈 수 영향

초록

Large eddy simulation(LES) of turbulent mass transfer in fully developed turbulent pipe flow has been performed to study the effect of Reynolds number on the concentration fields at Re_tau=180, 395, 590 based on friction velocity and pipe radius. Dynamic subgrid-scale models for the turbulent subgrid-scale stresses and mass fluxes was employed to close the governing equations. Fully developed turbulent pipe flows with constant mass flux imposed at the wall are studied for Sc=0.71. The mean concentration profiles and turbulent intensities obtained from the present LES are in good agreement with the previous numerical and experimental results currently available. To show the effects of Reynolds number on the turbulent mass transfer, the mean concentration profile, root-mean-square of concentration fluctuations, turbulent mass fluxes and higher-order static (Skewness and Flatness factor) were presented. Furthermore, the budgets of turbulent mass fluxes and concentration variance were computed and analyzed to elucidate the effect of Reynolds number the on turbulent mass transfer.