Document Type : Research Article


1 Assistant Professor. Aerospace Research Institute, Ministry of Science, Research and Technology, Tehran, Iran.

2 Ph.D. Student. Aerospace Research Institute, Ministry of Science, Research and Technology, Tehran, Iran.


This paper investigates the heat transfers and ablation of thermal insulators used in motors and nozzles. The heat and mass transfer equations are considered in two dimensions in a convergent-divergent nozzle. The finite volume method and the implicit method for time dependence have been used to solve these equations. We used the equations finite volume method with implicit formulation for time dependency to solve equations. The reaction equation, which is written in the form of Arrhenius, is solved using the Runge-Kutta method, and the density and the flux of the gas produced at each step are obtained. Also, we represent a model for the rate of recession. The validation of the model is compared with the experimental results in silica-phenolic ablation insulators and shows a good agreement of the simulation results with the experimental observations. After validation of the obtained results. The effect of the blowing correction coefficient has been investigated, the results show that this coefficient is very important for the accurate design of ablation insulators. The blowing correction factor reduces the convection heat transfer coefficient, reduces the surface recession, and thus, reduces the back temperature of the insulation. Therefore, in cases where the thickness of the insulation is significant or the heat of ablation is low. This parameter can be important and affect the final results and thus the final design.


Main Subjects

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