Theoretical Analysis of Transpiration Cooling of a Liquid Rocket Thrust Chamber Wall

Transpiration cooling is a process that could reduce the overall weight of the cooling system of an actively cooled thrust chamber wall of a liquid rocket engine by up to 50% when compared to other active cooling techniques, increasing the thrust to weight ratio of the rocket engine. In this thesis, mathematical models and computer codes were developed for simulating the flow of a coolant and the transport phenomena in a transpiration cooled thrust chamber wall of a liquid rocket engine by treating the coolant in two ways: as an incompressible fluid and as a compressible fluid in local thermal equilibrium with the porous structures that make up the thrust chamber wall. The programs were run with similar conditions and the results show that the incompressible flow model is a useful tool for accurately determining the temperature distribution inside the thrust chamber wall. The incompressible flow model was also used to perform parametric studies involving varying the thickness and porosity of the porous liner section of the wall. The results of these parametric studies show that varying the thickness and/or porosity of the porous liner can be utilized as a means for controlling the flow of the coolant inside the wall as well as its general function as a structural support for the thrust chamber wall