Large eddy simulation of turbulent concentric annular channel flows

Abstract

SUMMARYFully developed turbulent concentric annular channel ow has been investigated numerically by use of large eddy simulation (LES) technique coupled with a localized one-equation dynamic subgrid-scale (SGS) model. The objective of this study is to deal with the behaviour of turbulent ow near the inner and outer walls of the concentric annular channel and to examine the e ectiveness of LES technique for predicting the turbulent ow in uenced by the transverse curvature e ect. The computations are performed for the Reynolds number Re = 180, 395 and 640, based on an averaged friction velocity and the annular channel width with the inner and outer cylinder radius being R i = 1 and Ro = 2. To validate the present approach, calculated results for turbulent pipe ow and concentric annular channel ow are compared with available experimental data and direct numerical simulation results, which conÿrms that the present approach can be used to study turbulent concentric annular channel ow satisfactorily. To elucidate turbulence characteristics in the concentric annular channel, some typical quantities, including the resolved velocity, turbulence intensity, turbulent eddy viscosity, SGS kinetic energy, SGS dissipation rate, Reynolds stress budgets, and turbulence structures based on the velocity uctuations, are analysed.

A numerical investigation of turbulent flows in a spanwise rotating channel

“…To demonstrate that the results calculated by the numerical methods used are reliable, extensive validations have been undertaken in this study and in our previous work [35][36][37][38][39][40][41][42][43]. Usually, the high-order statistical turbulence quantities are more sensitive to the numerical methods.…”

“…Furthermore, some typical comparisons with the previous results, including the mean velocity, turbulence intensities and shear stress, and vorticity fluctuations, are also given in the following section. On the other hand, the relevant code and method have been verified in our previous work [35][36][37][38][39][40][41][42][43], in particular for detailed validations for stably and unstably stratified open channel flows based on DNS [35]. Thus, it is ensured that numerical approach is reliable to predict turbulence characteristics in the spanwise rotating channel.…”

Direct numerical simulation of spanwise rotating turbulent channel flow with heat transfer

“…All the above work confirms that the numerical approach with the second-order accuracy scheme is capable of reasonably predicting the turbulence characteristics. Meanwhile, the relevant code and method used here has been verified based on the extensive investigations of turbulent flow and heat transfer in our previous work [30][31][32][33][34][35][36][37], in particular, for the wall-normal rotating turbulent channel flow with heat transfer [21,38]. Thus, it is ensured that the present DNS is reliable to predict the turbulence and heat transfer behaviours in the rotating channel flow.…”

Large eddy simulation of stably stratified turbulent open channel flows with low- to high-Prandtl number

“…The present computational LES code has been verified extensively in our previous work [18,19,[27][28][29]. It can be ensured that our calculation is reliable for the prediction of statistical quantities of turbulent flow and heat transfer for thermally stratified turbulent flows.…”