A liquid rocket engine, which is also called a liquid propellant rocket engine, is a chemical
rocket engine using liquid chemicals (liquid propellant) as the energy source and the working
fluid. Liquid rocket engine technology has drawn researchers’ attention and been quite a hot
topic in aerospace and aeronautic research during the last 70 years. In the short long history of
human aviation, i.e., from the A-4 engine of the German V2 missile, to the F-1 engine of the
U.S. lunar landing rocket “Saturn 5” and further to reusable space shuttle main engines, every
milestone event is closely linked with the progress made in liquid rocket engine technology.
Because liquid rocket engines have the characteristics of high specific impulse, repeatable
starting, arbitrary working hours setting, multiple usage, adjustable thrust, etc., they are bound
to occupy the dominant position in the area of aerospace propulsion long into the future.
The liquid rocket engine uses liquid fuels as the propellant. In a liquid rocket engine, the
liquid chemical propellants combust in the combustion chamber and produce very high pressure
gas. The gas is accelerated when it flows downstream through the nozzle and produces
impulse, i.e., thrust, for the aircraft. There are several types of liquid propellants. The scheme,
structure, ignition and thermal protection, etc. of the liquid rocket engine have a close relationship
with the characteristics of the propellants used by the engine system.
The expansion of liquid rocket application requires more in-depth studies on the basic theory
and design method of the liquid rocket engine. Numerical simulation of the combustion process
in a liquid rocket engine is also an important research direction. This chapter introduces the
basic configuration and working process of liquid rocket engines, and then discusses the main
objective and research method of the numerical simulation of the combustion process in a
liquid rocket engine.