Mixed Convection Characteristic Inside a Thermal Cycling Chamber With Nonuniform Perforated Plate

The steady-state flow field and temperature distribution inside a thermal cycling test chamber with nonuniform perforated plate are investigated both numerically and experimentally. Porous zones are set up by pressure loss analogy to simplify the perforated plate. Boussinesq approximation and low-Re model are used in the simulation. The numerical result shows both forced convection and natural convection contribute to the fluid flow and heat transfer. For uniform perforated plate, the temperature at the given height always increases from the center line to the walls. And from top to bottom of the cycling chamber, temperature increases around the center line while decreases near the walls. Based on that, two cases of nonuniform perforated plates with the same ratio of open area and different holes distribution are examined to improve the temperature uniformity in test chamber. The results show that both average temperature and standard temperature deviation are effected significantly by nonuniform perforated plate. The latter experiment is performed with the optimal perforated plate under the same condition of Re = 4.1 × 10⁴, Gr = 1.8 × 10¹¹. The experiment results are obtained by Constant Temperature Anemometry and agree with the numerical simulation.