Parametric Analysis of Heat Transfer to Supercritical-Pressure Methane

Although methane has good properties as a coolant, its use in the regenerative cooling system of liquid rocket engines must take into account that it could be in a near-critical state and thus be subjected to large thermophysical property variations. The present study investigates on the influence of the thermodynamic and transport property variations on the methane heat-transfer capabilities. The parametric analysis is carried out by a parabolized Navier-Stokes solver developed by the authors, which includes an accurate equation of state as well as transport property models, able to describe methane in all the thermodynamic conditions of interest. Results show that a wall-temperature peak may occur at typical operating conditions of turbopump-fed engines, because of the heat-transfer deterioration phenomenon. A discussion on the range of methane operating conditions leading to this phenomenon is presented on the basis of the parametric analysis results and literature data.