Numerical Study of the Performance of Combined Spike and Transpiration Cooling Concept for Nose Cone under Hypersonic Conditions

During high-speed flight of hypersonic vehicles, the nose cone's stagnation point encounters a severe aerothermodynamic environment. Although traditional transpiration cooling can effectively decrease the structural temperature of the nose cone, the efficiency of the cooling process at the stagnation point will be hindered by the exceptionally elevated levels of heat flux and pressure surrounding the stagnation area. In this paper, a groundbreaking approach incorporating both spike and transpiration cooling methods has been suggested for enhancing nose cone cooling efficiency in hypersonic environments. The spike moves the bow shock wave away from the nose cone, reducing pressure and heat flux at the stagnation point, allowing coolant to flow out of the porous matrix more easily. The Reynolds-averaged Navier-Stokes (RANS) equations, along with the shear stress transport (SST) k-ω turbulence model, were used to model the flow field, with an additional focus on fluid-thermal coupling analysis. The data indicated that the temperature at the nose cone's stagnation point decreased by approximately 64% at an altitude of 30 km and free-stream Mach 6 with the new combined approach, demonstrating its practicality and effectiveness compared with traditional transpiration cooling methods. Further investigation was conducted on how the cooling performance of the combined configuration is affected by the flow rate and orientation of the porous matrix. Increasing the flow rate of the coolant reduced the temperature along the surface of the nose cone in a combined configuration, but the amount of temperature decrease decreased. Additionally, with an increase in the angle of the porous matrix, the temperature along the front surface of the nose cone decreased in a combined configuration, whereas the temperature at the stagnation point and along the downstream surface of the nose cone remained relatively constant. The combined spike and transpiration cooling concept proposed in this study significantly improves the cooling efficiency of the nose cone head under hypersonic conditions, which shows great application prospects for hypersonic thermal protection.