The aluminum-containing composite propellant burns in the acceleration field, dividing the dynamic process and the steady state process. In the dynamic process, when the combustion begins, the ignition temperature of the AP is low and the combustion is performed first. The heat released causes the HTPB binder to be in a molten state. The heat is transferred to the depth of the fuel column to preheat the aluminum particles and form in the AP. The accumulation and phase change processes are completed in the pockets, and aluminum particles also collide with adjacent aluminum particles to form agglomerated aluminum particles many times larger than the original aluminum particles, also called aluminum balls. Studies have shown that the velocity of the lower part of the aluminum ball next to the fuel surface is lower, and the velocity in the upper part of the aluminum ball is higher. According to Bernoulli's theorem, the pressure p on the lower surface of the aluminum ball is higher than the pressure pc on the upper surface, so the aluminum ball has a total Pressure difference F exists. It is also known that the acceleration force acting on the aluminum ball acts as a pressure differential lifting force, which overcomes the acceleration force a, raises the aluminum ball and causes it to leave the burning surface; when F plays the role of pressure difference resistance That is, F overcomes Fpdt and forces the aluminum balls to stay on the burning surface and forms pits on the burning surface. The aluminum balls have a small air gap λ at the bottom of the pits as if the aluminum balls were floating in the pits. Since the temperature of the aluminum ball is close to the gas temperature, and the temperature of the combustion surface is much lower than the temperature of the aluminum ball, thermal energy is fed back to the combustion surface through the air gap λ. Therefore, the formation of a heat source due to the aluminum balls remaining on the combustion surface is an important cause of the increase in burning rate. The greater the acceleration, the higher the content of aluminum powder and the lower the static burning rate, the more aluminum particles will stay on the combustion surface, the more feedback heat will be, the higher the burning rate r, the average burning rate. The larger the ratio r is. The combustion performance of the 2010 propellant is very sensitive to acceleration. Under the condition of an acceleration of 70g, the average effective burning rate ratio r is as high as 1.515. This is mainly due to the high content of aluminum powder and low static burning rate. The acceleration sensitivity of the propellant is mainly manifested in the increase of the burning speed of the propellant, which in turn induces an increase in the pressure of the combustion chamber, a shortening of the combustion time and a change in the inner ballistic performance. The results of this study have practical implications for evaluating propellant formulations and predicting the ballistic performance of solid rocket motors. Acceleration sensitivity of burning rate poses a threat to the safety of rocket flight. Further research on the acceleration effect is necessary.
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