New discrimination method for ablative control mechanism in solid-propellant rocket nozzle

A reasonable discrimination method for ablative control mechanism in solid-propellant rocket nozzle can improve the calculation accuracy of ablation rate. Based on the different rate constants for reactions of C with H2O and CO2, a new discrimination method for ablative control mechanism, which comprehensively considers the influence of nozzle surface temperature and gas component concentration, is presented. Using this new discrimination method, calculations were performed to simulate the nozzle throat insert ablation. The numerical results showed that the calculated ablation rate, which was more close to the measured values, was less than the value calculated by diffusion control mechanisms or by double control mechanisms. And H2O was proved to be the most detrimental oxidizing species in nozzle ablation.