Transverse buoyant jet-induced mixed convection inside a large thermal cycling test chamber with perforated plates

Transverse buoyant jet-induced mixed convection inside a large thermal cycling chamber with perforated plates is investigated experimentally and numerically. The mean temperature distribution and temperature fluctuation are obtained experimentally under cooling and heating conditions. The numerical simulation is conducted by solving the Reynolds-averaged Navier-Stokes (RANS) equations using the low-Re k-epsilon model. The modified body force based on the pressure loss analogy is adopted to describe the flow characteristics through the perforated plate. An additional transport equation is solved to determine the root mean square (RMS) of the temperature fluctuation. The proposed numerical method is validated with the experimental data. The flow field, mean temperature distributions, and RMS of the temperature fluctuation are studied for various values of the pressure loss coefficient of the perforated plate Eu and the dimensionless heights of the plenum h. The results indicate that the mixed convection flow field is characterized by the inertial force from the inlet, the buoyancy force due to the temperature difference, and the dissipation effect of the perforated plate. For a larger Eu, the temperature uniformity of the test zone is greatly improved, and the average RMS temperature fluctuation also decreases. The dimensionless height of the plenum h has little effect on the development of the buoyant jet. The average temperature deviation and RMS temperature fluctuation exhibits a slight decrease with increasing h.

Automated summary

In this study, the mixed convection induced by transverse buoyant jet inside a large thermal cycling chamber with perforated plates was investigated experimentally and numerically. The results show significant effects of the pressure loss coefficient and the plenum height on the temperature distribution and fluctuation, where the flow characteristics are influenced by multiple forces. For larger pressure loss coefficients, the temperature uniformity in the test zone is greatly improved.