Cooling performance optimization of supercritical hydrocarbon fuel via bi-directional flow pattern

Abstract

• A novel bi-directional flow (BDF) pattern for regenerative cooling is proposed. • BDF achieves more homogeneous temperature distribution and higher fuel conversion. • BDF increases slightly pressure drop and surface temperature at the same time. • A hybrid flow pattern is recommended to maximize the cooling performance. Regenerative cooling is a promising method to meet the increasing heat management requirement of hypersonic vehicles. In contrast to the traditional co-directional flow (CDF) pattern, here we propose an innovative bi-directional flow (BDF) pattern inside rectangular parallel channels to improve the active regenerative cooling performance. Based on a reliable CFD model, the flow and heat transfer performance of n -decane under two types of thermal boundaries are analyzed. Three types of channels at different locations considering buoyancy effect are also investigated. By observing the contour of specific heat, mass fraction of n -decane, temperature distribution, velocity field and calculating the heat sink and surface heat transfer coefficient, the cooling performance of BDF pattern is discussed and compared with that of CDF pattern. Results reveal that compared to the CDF pattern a more homogeneous temperature distribution and a higher conversion of n -decane (around 14% increment under thermal boundary: 1.9 MW/m 2 and 1400 K) are obtained by BDF pattern. However, an increased pressure drop within a reasonable range and a higher surface temperature are observed for the BDF pattern. With overall consideration, a hybrid flow pattern is proposed which could maximize the cooling effect within the surface temperature constraint yet keeping its simple inner structure.