Numerical Simulation of a Hydrogen-Fueled Scramjet Added With a Porous Burner at Different Mach Numbers

This study presents a numerical investigation of a hydrogen-fueled scramjet engine integrated with a porous burner to enhance flameholding and thrust performance across air inlet speeds from Mach 2 to Mach 5. Using validated CFD simulations, the research examines the effects of the porous burner configuration, fuel distribution, and burner size. The results show that the porous burner significantly improves flameholding, particularly at higher Mach numbers where conventional designs suffer flame blowoff. Equal fuel injection from the strut and the burner yields optimal combustion efficiency and thrust. Fixing the global equivalence ratio increases thrust at high speeds, and reducing burner size lowers the pressure loss, enhancing net thrust—improving it from −1.52 N to 2.02 N at Mach 5 air inlet speed without additional fuel. However, excessively small burners (Λ < 1) destabilize the flame when located too close to the strut, whereas placing these small burners further downstream can re-establish a stable flame at Mach 5 with no net thrust trade-offs. These findings support the porous burner’s potential in advancing high-speed scramjet propulsion.