Experimental Study of Rectangular Channel Heat Transfer With Buoyancy-Aided Flow Under Asymmetrically Heating

Abstract Many nuclear power facilities use natural air circulation as part of their non-energetic safety mechanisms to remove heat. Both forced and spontaneous convection are frequently involved in the flow during this cooling process in vertical channels. The flow is referred to as buoyancy-aided flow when the direction of forced convection and natural convection coincide. The mixed convection heat transfer coefficient is lower than the forced convection heat transfer coefficient, and this type of flow will be in a specific buoyancy range. The supercritical fluid and water as the working medium, four-sided test mode heating, asymmetric heating, and air as the work material of the experimental research are the main topics of current research on buoyancy-aided flow. Thus, the investigation of mixed convection under buoyancy-aided conditions is presented in this study, along with a comparison of the experimental findings with the current correlations and an analysis of the causes of the differences. Lastly, a modified Buoyancy number with an average deviation of +20% is offered as a new correlation. This will serve as a point of reference for the relevant mixed convection heat transfer calculation.