Investigation of the steady-state temperature field characteristics inside a thermal cycling test chamber of turbulent mixed convection.

The steady state temperature field in a thermal cycling test chamber, where both the forced convection and natural convection contribute to the flow and heat transfer, is investigated by combined numerical and experimental method. A simplified algorithm has been developed for the wall boundary condition to deal with the complex wall compositions and the k-ε model is used for turbulence, which is validated by performing full scale experiments in a real system. The results show the steady temperature increases from top to bottom at the vertical centerline of the chamber and increases from bottom to top near the walls, due to the buoyancy force induced secondary flow. For the existing thermal cycling test chamber, the effects of the inlet flow rate and inlet temperature on the average temperature and the temperature uniformity are examined in the range of parameters 2.2 × 103 ≤ Re ≤ 4.3 × 106, 2.3 × 1013 ≤ Gram ≤ 3.6 × 1014 and Pr = 0.71.