Heat Management in Supersonic/Hypersonic Vehicles Using Endothermic Fuel: Perspective and Challenges

In this study, an in-depth analysis has been performed on various technoengineering aspects of hydrocarbon cracking under supercritical conditions toward developing an endothermic fuel. The paper is segregated into several sections with specific emphasis. The major areas covered in this work include physicochemical characteristics of different endothermic fuels, supercritical pyrolysis of hydrocarbon fuels, phenomena of coking, and its suppression from an application viewpoint. The influence of various parameters (e.g., temperature, pressure, catalysts, space-time, etc.) on fuel conversion, endothermicity, and coke propensity has been emphasized in detail. The typical value of endothermic heat sink capacity for different fuels consisting of C-8 to C-15 hydrocarbons ranges from 500 to 1150 kJ/kg over temperature and pressure ranges of 550-750 degrees C and 25-55 bar, respectively. The effectiveness of various additives/initiators in improving endothermicity has been screened for wide ranges of temperature and pressure. Physicochemical properties like distillation characteristics, hydrocarbon composition, degrees API gravity, and sulfur content of different hydrocarbon fuels are compared in a single window. Most of the findings are abridged meticulously with relevant tables and plots. Toward the end, we have highlighted the critical issues/challenges on the experimental findings and prospective.