Investigation on the thermal mixing enhancement in a T-junction pipe

In this paper, three-dimensional numerical simulations are conducted to study the thermal mixing of turbulent flow in a T-junction with hot fluid flowing in the main pipe and cold fluid in the branch. The main objective is to investigate the effects of the axial and cross-injection angles to the main pipe and the branch-to-main flow rate ratio on the turbulent thermal mixing. In this regard, an appropriate mixing index is proposed to evaluate the thermal mixing efficiency. The turbulence model employed in this research is the SST k-omega model that can properly capture the mixing behavior of the flow in the main pipe. The results show that the cross-injection angle can considerably affect the thermal mixing enhancement. However, the effects of injection angles on the thermal mixing at lower flow rate ratios are more significant.