THERMOCHEMICAL DEGRADATION OF CARBON COMPOSITE MATERIALS DURING SOLID-PROPELLANT BENCH TESTS
R. D. Berdov, L. I. Volkova, A. S. Golovatyuk
Keldysh Research Center, Moscow, Russia
Keywords: carbon composite material, fire test, solid propellant, chemical erosion, oxidation
Abstract
The effect of a gas curtain, formed by the destruction products of thermal protection elements in the combustion chambers of solid-propellant gas generators, on the material degradation of critical-section liners is investigated. Experimental data from two series of fire tests conducted on test benches are analyzed: one series performed by the authors and another reported in the literature. Both test series yield relatively low linear material loss rates, measuring 2.5 and 6 times lower, respectively, than those calculated using methods for large-scale solid-propellant rocket motors. A mathematical model is proposed based on the coupled solution to integral momentum and energy equations for the boundary layer and on the determination of the thermal state and failure of materials. This model allows for the introduction of additional admixtures of a cold gas, which is chemically inert with respect to carbon, into the fuel combustion product flow. The applicability of the model is validated by comparing simulation results with experimental data, with discrepancies not exceeding 5%.
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