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Coupling Simulation of Heat Transfer and Temperature of the Composite Walled Nozzle of Rocket

Estimation the temperature distribution on nozzle wall by predicting the thermal environment is most important for assessing the life of the nozzle. For that purpose, the coupling simulation of the conjugate heat transfer and transient temperature on the rocket nozzle wall is studied. The equation of radiative heat flux on surfaces of an enclosure filled with inhomogeneous, participating media is established to compute the radiative heat flux, the Bazi equation is used to compute the convective heat transfer at the nozzle wall from the hot gases, the differential equation of 2-D transient conduction in cylindrical coordinate is established and discretized with reclusion form. The conjugate heat transfer coupling with the transiental temperature of two composite walled nozzles are computed, one is the nozzle of an experimental rocket engine fabricated with stainless substrate and a ZrO2 coating, the other is constructed with multi-layer composite materials. The results show that: the temperatures both on the inside and outside faces of the rocket nozzle increase with time after startup of the rocket engine, the former increase rapidly while the latter increase slowly. On the same cross section, the temperature decreases along the radius inside the wall, which is maximal at the outside face while minimal at the inside face. The temperature of the straight and contraction section of nozzle increases as axial coordinate increases and becomes maximal at the throat, while decreases with axial coordinate in diverging section. The coupling simulation method and the computed results are tested reasonable by comparing the computed results with reported results in reference.