Theoretical modelling for effects of arbitrary surface catalysis on peak heat flux in laminar compression corner flows

Theoretical analysis and numerical simulations using computational fluid dynamics (CFD) were conducted to investigate hypersonic laminar flow over a compression corner, focusing on the effects of arbitrary surface catalysis on peak surface heat transfer. Four groups of inflow conditions were considered, varying in Mach number (8-12), unit Reynolds number (2 × 105-8 × 105 m -1), degree of dissociation (0.05-0.15), and ramp angle (20°-28°). The results indicate that while wall catalysis has a negligible effect on the flow structure, it significantly influences the peak surface heat transfer near the reattachment region, even for finite-rate catalytic walls. A predictive formula is proposed for the non-dimensional catalytic heating, considering finite-rate catalytic walls. CFD results show that the peak heat flux increases as the catalytic coefficient increases due to enhanced surface recombination of atoms, and the effectiveness of the formula is further verified by oxygen inflow. Finally, the catalytic heating ratio at the location of peak surface heat transfer is evaluated by the formula using catalytic coefficients of real materials. It is shown that the catalytic heat flux ratio may increase by approximately 50% from oxygen inflow to nitrogen inflow for copper under the same nominal freestream.