Characteristics of scramjet regenerative cooling with endothermic chemical reactions
The regenerative cooling technique with endothermic reactions is prospective for scramjet engines, in which the convective heat transfer characteristics are necessary for the thermal system design. In this work, the turbulent heat transfer characteristics of hydrocarbon fuels with endothermic chemical reactions were experimentally and numerically investigated. Three kinds of surrogates and two different pressures were employed to obtain various chemical endotherms, and the distributions of physical properties and dimensionless parameters were analyzed in the chemical region. Results showed that endothermic chemical reactions improved the convective heat transfer performance, even though the variations of fluid Reynolds number and Prandtl number brought by chemistry were small. Then, a dimensionless parameter was proposed to describe the proportion of chemical endotherm capacity. The numerical results revealed that the natural logarithm of Nusselt number enhancement changed linearly with the proposed dimensionless parameter, and the slopes were irrelevant to reactant types or chemical conditions. Last, by modifying the Dittus-Boelter correlation, a novel Nusselt number correlation was put forward for the endothermic reacting flow. Based on the analysis of the existing data and the formula form, continuously increasing the fuel chemical endotherm might bring a smaller benefit of Nusselt number augmentation.
危险品化学品经营许可证（带存储）