ACTIVE COOLING OF A HYPERSONIC PLANE USING HYDROGEN, METHANE, OXYGEN AND FLUORINE

This paper studies active cooling of an aerospace plane using liquid h ydrogen, liquid methane, liquid oxygen and liquid fluorine. An ascendi ng optimized trajectory to minimize the heat load in the hypersonic pa rt is used to perform the study, which includes cooling of the stagnat ion point, the leading edges of wings and engine and other parts of th e aerospace plane that are close to the leading edges. The laminar cas e of the stagnation point and both laminar and turbulent cases for the leading edge heating have been considered. The amount of liquid coola nt mass needed for cooling is calculated. A design of minimum inlet-ou tlet areas for the amount of liquid needed for cooling is made with co nsideration of the coolant's physical constraints in the liquid and ga seous states: The study shows that the ratio of masses of coolant to t he initial total mass (initial total mass of the vehicle including fue l and coolant masses) is in the limit of the reachable range. The comp arison shows that the hydrogen is a clear winner as a candidate for co olant and saves mass as compared to the other three coolants. The stud y shows that there are no fundamental barriers for the cooling system of the vehicle in terms of its coolant mass and area size for coolant passage.