Effects of gas-phase speed on EPDM insulator ablation

In order to understand the effects of gas-phase speed on insulator ablation, EPDM insulator ablation experiments were carried out with a test motor, in which double base propellant was used.The particle effect was excluded in the test. The charring ablation rate, the carbon layer structure and the distribution of main ingredient under different gas speed environments are analyzed. The results showed that in the gas environment without particles, the charring ablation rate increased slightly and the gas-mechanical effect increased obviously while gas speed increased. The profile of every sample has the same character and the main ingredient has the same distribution regularity along the thickness. The ablation of EPDM insulator regards pyrolysis and carbonization as principle under the lower gas speed.The mechanical breakage of the carbon layer plays an important role under the higher gas speed. The experimental results may be used for further research for ablation principle of EPDM insulator.