Numerical investigation of spike-assisted transpiration cooling for a hypersonic leading edge: Shock-wave regulation and coolant redistribution
Year: 2026
Type: article
Abstract: The stagnation region of hypersonic vehicle leading edges is subjected to strong shock compression, resulting in a high-temperature and high-pressure environment that suppresses coolant discharge in conventional transpiration cooling and poses a major challenge to improving active thermal protection performance. To enhance coolant transport under severe pressure and thermal conditions, a combined spike–transpiration cooling configuration is proposed to reduce the leading-edge thermal load through the coupled effects of external flow field regulation and internal coolant transport. A coupled numerical model of the freestream, porous medium, and solid wall is developed using the SST k–ω model, the Brinkman–Forchheimer porous medium model, and species transport, and is validated against separate experimental datasets for transpiration cooling and spiked-body aerothermal flow. The thermal protection performance of four configurations, namely the bare leading edge, transpiration cooling alone, spike alone, and combined configuration, is compared. The effects of angle of attack and spike length-to-radius ratio on the cooling performance are further investigated. The results show that the spike effectively reduces the external pressure environment near the leading edge, decreasing the wall static pressure at X /L = 0 from 109.24 kPa for the transpiration-cooling-only configuration to 35.52 kPa for the combined configuration. This reduces the external backpressure acting on the porous wall and provides more favorable pressure conditions for transpiration cooling. The combined configuration suppresses temperature peaks in both the stagnation and reattachment regions, reducing the maximum wall temperature from 895.90 K for transpiration cooling alone to 711.82 K, with combined-effect coefficients ranging from 0.68 to 0.84. As the angle of attack increases from 2° to 6°, the mean cooling effectiveness decreases from 0.75 to 0.70 on the windward side due to increased pressure, but increases from 0.81 to 0.87 on the leeward side owing to coolant redistribution. Nevertheless, the combined configuration maintains superior thermal protection performance compared with transpiration cooling alone at all investigated angles of attack. Increasing the spike length-to-radius ratio ( l /R) from 1 to 2 reduces the wall static pressure at X /L = 0 by 36.74%, raises the mean cooling effectiveness from 0.76 to 0.82, and increases the minimum cooling effectiveness from 0.58 to 0.70. These findings reveal the mechanisms by which shock-wave regulation and transpiration cooling jointly enhance thermal protection and provide a new design approach to overcoming coolant transport limitations under the high-pressure conditions encountered at hypersonic leading edges.
Authors: Yaoxuan Jiang, Xingchun Xu, Hongyue Wang, Jiaqi Zhu
Institution: Harbin Institute of Technology
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,620
OpenAlex ID: W7203754089