Numerical study of natural convection in a cavity with discrete heat sources

Abstract.

Natural convection heat transfer in a cavity has always attracted researchers interest because of its numerous applications in engineering, e.g., cooling of electronic parts, thermal insulators, buildings ventilation systems, solar collectors, and nuclear reactors. In general, due to favorable factors, such as process simplicity, cost-effectiveness, low noise, and the possibility of recovery, the process of natural convection has many uses in various industrial applications. In this study, a square cavity with air inside is considered. Three heaters are situated at the bottom wall, the top wall is maintained at a constant cold temperature, and the two side walls are insulated. The lattice Boltzmann method is used for simulation, and the overall goals are to optimize the installation location and heater length and also investigating the effects of the amplitude and oscillation period of heat flux fluctuation. The results indicate that increasing the difference between amplitudes and oscillation periods of heat flux in heaters causes the flow within the cavity to stabilize more quickly and also increases temperature oscillation due to larger amplitudes and periods. Also, in the cavity with three heaters, the average temperature of the middle heater remains unchanged relative to the case of constant heat flux. This research can be used in the design of an appropriate cooling system for electronic components to ensure effective and safe operational conditions.