ANALYSIS OF EFFECTS OF ROCKET-ENGINE DESIGN PARAMETERS ON REGENERATIVE-COOLING CAPABILITIES OF SEVERAL PROPELLANTS

摘要

An analytical study was conducted to determine the influence of several design parameters on the cooling requirements of some high-energy, regeneratively fuel-cooled rocket engines. These parameters include engine size, combustion-chamber pressure, contraction and expansion area ratios, propellant combination, fuel-oxidant mixture ratio, and performance efficiency. The nominal thrust levels considered were 1000, 10,000, 100,000, and 1,000,000 pounds;and the propellant combinations were hydrogen-fluorine (H2-F2), hydrogen-oxygen (H2-02), hydrazine-fluorine (N2H4-F2), ammonia-fluorine (KH3-F2), and jet-engine fuel and oxygen (JP4-O2). The engines considered were of cylindrical chamber design, and expansion to sea-level conditions was specified except where variations in expansion area ratio were under study. The cooling system was such that the fuel flowed axially (from nozzle exit to injector) in an annular jacket along the entire engine length. Some of the engines employed the additional cooling aid of a ceramic lining in the combustion chamber and nozzle.nThe analysis revealed the areas of feasible application of regenerative fuel-cooling for the various propellant combinations. In general, propellant combinations using hydrogen as the fuel and coolant displayed the best cooling possibilities of the combinations studied. The application of chamber and nozzle ceramic linings, of course, improves the possibility of cooling where it might otherwise be marginal or impossible. The most important influencing parameters with respect to the cooling requirement of a particular propellant combination, in approximate order of decreasing influence, are engine size, performance efficiency, fuel-oxidant mixture ratio, expansion area ratio, combustion-chamber pressure, and contraction area ratio.