Numerical studies of the enhanced thermal performance of regenerative cooling channel with triangular micro-rib

Regenerative cooling technology plays a critical role in the thermal management of scramjets. However, its application in high Mach vehicles is limited by severe thermal stratification of n-decane, employed as a single-component surrogate for aviation kerosene, in the cooling channel. The incorporation of triangular micro-rib has received considerable attention for its potential to enhance fluid turbulence and heat transfer. To further elucidate these effects, this work employs computational fluid dynamics to simulate the cooling channel featuring a single triangular micro-rib with varying inclinations and placements. The simulations reveal that setting the triangular micro-rib close to the initial heating point yields markedly enhanced heat transfer compared to an end-positioned configuration. The optimal placement of micro-rib is determined to be 56 mm from channel inlet. This configuration raises the fluid outlet temperature by about 15 K over the smooth channel, achieving maximum total heat absorption. The triangular micro-rib with an aspect ratio e/h = 1/1 leads to an optimal trade-off, providing a heat sink of n-decane about 1.0 × 10³ J/kg higher than that in rectangular rib channel, coupled with a 36.7 % reduction in stress compared to the e/h = 1/2 design.