A Comprehensive Theoretical Model for Carbon-Carbon Composite Nozzle Recession

Abstract

Abstract A comprehensive aerothermochemical model for the process of C/C nozzle recession has been developed. The analysis accounts for both diffusion and chemical kinetics effects on the recession process. The gas-phase conservation equations are Favre-averaged to account for variable density effects. The turbulence modeling consists of a two-equation (K-ϕ) turbulence closure model for the final averaged gas-phase conservation equations. The solid-phase equations consist of the transient heat-conduction equation For the C/C nozzle with a recessing surface. The governing set of equations is solved numerically. Predicted results compared well with Geisler's experiment data. The recession process was found to be limited by the diffusion of oxidizing species such as H2O and CO2 to the nozzle surface. Chemical kinetics limited the recession rate only in the initial period when the nozzle surface temperatures were low. The recession rate was found to increase with increasing concentration of oxidizing species in the propellant exhaust, increasing chamber pressure, or increasing surface roughness.