Computational study of Rayleigh-Bernard convection in a cylindrical pressurized cryogenic tank*

This research discussed a joint CFD-nodal computational approach for flow modeling inside a closed pressurized cryogenic tank. The effect of the tank’s physic on the Rayleigh-Bernard convection is explored. Our primary goal is to alleviate the drawback of pure nodal approaches for capturing the flow physics and thermodynamics of cryogenic flows in storage vessels and reduce the expensive computational cost of full CFD simulations through the employment of coupled nodal and CFD approaches. The proposed algorithm is tested for a cryogenic fuel tank with the assumption that the exchange between the phases is due to the thermal and mass boundary conditions at the liquid/gas interface. The Nodal and CFD models are coupled through a 0D/3D interface coupling wherein the CFD approach is employed for the liquid domain. We show that the presented 0D/3D connection of the CFD and Nodal with proper temporal coupling at their interfaces can be employed to efficiently study the flow and thermal physics of storage tanks. The role of the tank’s aspect ratio, Rayleigh number, and the volume ratio of gas to liquid parts on the circulation patterns and thermal stratification in tanks will be discussed.

 

Grant support (80NSSC20K0352) from the National Aeronautics and Space Administration (NASA) is gratefully acknowledged.