A thermal/fluid analysis of perforated plates for transpiration-cooled rocket chambers

Increasing liquid rocket performance will require the use of active cooling techniques. A new drawing process to fabricate metal plates with very small, uniformly distributed holes has been developed. These plates could be used for transpiration cooled combustion chambers and nozzle throats. A numerical analysis was performed to characterize the geometric and fluid mechanic requirements for a porous coolant annulus to maintain the wall of a NASA calorimeter chamber operating at a hydrogen-oxygen mixture ratio of 6, 2200 psia, and 6446{dollar}spcirc{dollar}R below 1460{dollar}spcirc{dollar}R. A one-dimensional thermal/fluid computational model was developed to predict the temperature distribution through the thickness of the porous copper wall and in the hydrogen coolant. The model accounts for variable thermodynamic properties and the effect of surface blowing on the hot gas convective heat transfer. The effects of coolant mass flow rate and wall thickness were parametrically investigated. The study indicated transpiration cooling is an effective way of cooling the combustion chamber in a liquid rocket nozzle. However, potentially high thermal stresses must also be considered.