A Rocket Engine is a type of jet engine that uses only stored rocket propellant mass for forming its high-speed propulsive jet. Rocket engines are reaction engines obtaining thrust in accordance with Newton’s third law of motion. Most rocket engines are internal combustion engines although non-combusting forms (such as cold gas thrusters) also exist.
In Rocket Engine, the heat created in the combustion chamber during combustion process is about 2800K-3500K, which contains exhaust gases.Most of this heat is expelled along with the gas that contains it; however, heat is transferred to the thrust chamber walls. Due to this high temperature, there will be an existence of damaging the walls of the thrust chamber and nozzle. cooling system cooling system cooling system cooling system cooling system
To hold such high temperature effectively, the Regenerative Cooling method is used. Regenerative cooling is the most widely used method of cooling a thrust chamber and is accomplished by flowing high-velocity coolant over the back side of the chamber wall to cool the hot gas liner. In this method, the fuel itself acts as a coolant because in liquids huge amount of heat transfer takes place quickly as compared to air or other gases. The coolant with the heat input from cooling the liner is then discharged into the injector and utilized as a propellant.
Earlier thrust chamber designs had low chamber pressure, low heat flux and low coolant pressure requirements, which could be satisfied by a simplified “double wall chamber” design with regenerative and film cooling. Later, chamber pressures were increased and the cooling requirements became more difficult to satisfy.
This led to the design of “tubular wall” thrust chambers, by far the most widely used design approach for the vast majority of large rocket engine applications even in Air Force and NASA. The primary advantage is its light weight and the large experience base. But as chamber pressures and hot gas wall heat fluxes continued to increase resulted in more effective methods.
One solution has been “channel wall” thrust chambers, the hot gas wall cooling is accomplished by flowing coolant through rectangular channels, which are machined into a hot gas liner fabricated from a high-conductivity material, such as copper or a copper alloy. Heat transfer and structural characteristics are excellent in this case.