Numerical Analysis of Supercritical Methane Heat Transfer in Regeneratively Cooled Liquid Propellant Rocket Engines

This study investigates supercritical heat transfer in regeneratively cooled liquid propellant rocket engines LPREs using methane as the coolant, through three-dimensional numerical simulations. A circular channel with asymmetric heating on the bottom surface of the wall is used to determine the influence of boundaries conditions on heat transfer and thermal deterioration. Higher operating pressure enhances heat transfer, while excessive heat flux and/or low inlet velocity can lead to thermal deterioration. In addition, for channels with the same surface area but different passage shape geometries, the impact on wall temperatures and pressure losses is evaluated. Rectangular channels, although offering better heat transfer compared to the circular channel, have high pressure losses, especially for high aspect ratios. Alternative shapes like "Cir/Rec" and "Ellip" presented a good balance between heat transfer and pressure losses, and the "Mixed" shape proved to be the most promising solution. These findings pave the way for optimized LPRE designs using supercritical methane.