EROSION EVALUATION OF NOZZLE THROAT INSERTS

A study has been conducted to evaluate the temperature distribution and recession behavior of graphite nozzles in rocket motors by solving two-dimensional transient heat transfer equations. Flowfield analysis takes in account the effects of A12O3 concentration through the contribution of particles on the stream density and temperature. The analytical model assumes that there is radiant exchange between the gas stream and the wall. An effective emissivity is used in this parallel plate radiation model. The results calculated in radiation and non-radiation conditions are compared for aluminized propellants, and also checked with data of Keswani and Kuo. The laboratory motor tests with double base propellants have been performed for verification of the analytical model. The temperature profiles in the nozzle have Been measured at four locations with Cr-Ni/Ni-Si sheathed thermocouples. The present model is in general agreement with the available experimental data