Heat transfer enhancement in regeneratively cooled rocket engine channels using interrupted staggered inclined ribs

Liquid rocket engine thrust chambers experience heat fluxes up to 160 MW/m 2 , requiring highly effective regenerative cooling. This study investigates interrupted staggered inclined ribs for enhancing heat transfer in rectangular cooling channels with supercritical hydrogen. Three-dimensional conjugate heat-transfer simulations using the k - ω SST model show that the interrupted ribs generate local jet acceleration and secondary vortices, improving near-wall mixing while reducing flow blockage compared with continuous ribs. A regularized dual-hidden-layer backpropagation neural-network surrogate is trained using 87 representative CFD samples and evaluated by five-fold cross-validation, achieving R 2 > 0.985 for N u / N u 0 , f / f 0 , and PEC. Coupling the surrogate with NSGA-III identifies an optimized design with α = 44.71 ° , d = 4.000 mm , and d 2 = 0.500 mm , yielding P E C = 1.947 . CFD verification confirms close agreement with the surrogate prediction. The proposed CFD–BPNN–NSGA-III framework offers an efficient route for optimizing ribbed regenerative cooling channels.