Large-eddy simulation of velocity fluctuation of hot and cold fluids mixing in a tee-junction.

The turbulence effect of hot and cold fluids mixing in the tee-junction led to fluctuations of velocity, which is the essential cause of fluid flow inducing thermal fatigue of pipe. In order to reveal the cause, fluids mixing for the case with hot fluid in main duct and cold fluid in branch duct of a tee-junction was numerically simulated by large-eddy simulation. Numerical results of time-averaged and root-mean square velocities were compared with experimental results in a profile. The good agreement of numerical results with experimental ones indicates that large-eddy simulation can exactly predict the time-averaged velocity and velocity fluctuation of mixing process. Numerical results show that the profiles of time-averaged and root-mean square velocities in x and z directions along z direction have the trend of becoming uniform with the increase of x/d_b and decreasing with the increase of y/d_b. [ABSTRACT FROM AUTHOR]