Opposed Rows of Jets Injected into a Heated Crossflow: Investigation of Different Turbulent Heat Flux Models

The present paper discusses the importance of turbulent heat flux modeling in the numerical simulation of opposed rows of coolant jets injected normally into a confined heated crossflow. The Reynolds stress model (RSM) is used for the flow field modeling. Three different turbulent heat flux models are employed for the heat transfer modeling. The simple eddy diffusivity (SED), the modified SED model (MSED) and a combined expression of the generalized gradient diffusion hypothesis (GGDH) and the quadratic form of GGDH (AS) are examined for modeling the turbulentheat flux vector, uiq . The finite volume technique is employed to discretize the governing equations. Results are compared with the existing experimental data. Comparisons show that turbulent heat flux modeling plays an important role in accurately predicting the heat transfer in the field of jet in crossflow. Also, present results illustrate that the MSED and AS models give a better prediction for the dimensionless temperatureprofile in comparison with the SED model. Although the SED-based models can not capture the streamwise component of heat flux vector well, the AS model reasonably predicts the maximum value of this component.

Keywords:

numerical simulation , opposed jet incrossflow , Reynolds stress , turbulent heat flux modeling