Enhanced heat transfer of supercritical n-decane in cooling channels with triangular ribs for regenerative cooling

Abstract

• A continuous ribbed channel is designed to enhance the cooling capacity. • The channel can provide up to 2.04 times superior heat transfer performance. • The insertion of ribs enhances the uniformity of buoyancy distribution. • The triangular rib channel improves axial temperature uniformity. • The mechanism of generating vortices in the slot is analysed. Regenerative cooling is regarded as an effective method for managing the heat of scramjet combustors, and the design of cooling channels is critical for removing more heat from the engine. A continuous triangular rib channel was proposed. The effects of rib position, height, and pitch on the heat transfer performance were investigated using Fluent 18.0. The SST k –ω turbulence model was used to study the thermal behaviour of supercritical n-decane in channels and showed good agreement with the experimental data. Results show that the insertion of triangular ribs at the bottom and top can reduce the bottom wall temperature by 243.8 K in the studied case. The triangular rib channel can provide up to 2.04 times superior heat transfer performance. The continuous triangular ribs significantly reduced axial temperature inhomogeneity. Local streamlines were studied to demonstrate the influence of rib parameters on the flow and heat transfer processes. A local heat transfer enhancement occurs when the rib has a large inclination. For the studied conditions, the generation of vortices was carefully evaluated, and it was found that the generation of vortices in the slot was related to the value of h / p .