Numerical study of liquefied natural gas as a coolant in liquid rocket engines

Liquefied natural gas is a suitable propellant to be used, together with liquid oxygen as oxidizer, in a liquid rocket engine, because of possible advantages with respect to hydrogen in specific applications. Often approximated as pure methane, liquefied natural gas is a mixture of methane, other heavier hydrocarbons and nitrogen. If is to be used in a regeneratively cooled liquid rocket engine, the knowledge of the thermodynamic and heat transfer characteristics when it flows in the cooling channels is of primary importance. The present study is carried out to understand how the composition can influence the flow in cooling channels. Results show that increasing ethane and propane content in a mixture, the pressure drop decreases but the coolant capability worsens. On the other hand increasing nitrogen content causes both poorer coolant capability and larger pressure drop.