Rocket Engine Variable-section Grain Internal Ballistics And Structural Integrity Analysis

Solid rocket motor is an important part of rocket,its internal ballistic performance will directly affect the range and accuracy of the rocket,through the reasonable design of the column can obtain better internal ballistic performance.In order to solve the problem of large initial ventilation parameters of equal-section columns,this paper uses a combination of theoretical derivation and simulation calculation to study the variable-section column,and the main work content is as follows:The results of the ground stationary test of a certain rocket motor were analyzed,the fuel velocity curve in exponential form was fitted,the ballistic trajectory in the test engine was programmed,and the correctness of the program was verified through the test data.The theoretical model of variable-section charge is derived,the parametric modeling method is used to verify the accuracy of the theoretical model,and the internal ballistic calculation is calculated by MATLAB software.The results show that the cone charge can reduce the initial ventilation parameters,the specific impulse increases with the increase of the diameter and length of the charge,decreases with the increase of the inclination angle,and the larger the diameter and length of the charge,the smaller the specific impulse reduction when the inclination angle increases.The variable section star-hole column can effectively increase the volume loading coefficient,increase the pressure and thrust total impulse,reduce the initial pressure peak and increase the engine working time.The structural integrity of the charge was analyzed by the variable section drug column,the effects of inclination angle and transition section length under internal pressure load on the mechanical properties of variable section star hole drug column were studied,and the mechanical properties and displacement changes of variable section drug column after curing and cooling were analyzed.The results show that the maximum displacement of each section of the variable section star hole drug column under internal pressure and temperature load is near the half-angle of the star root of the small end face,and the maximum Mises stress and strain appear near the half-angle of the star tip,and change linearly along the axis of the drug column.The maximum Mises stress and strain of the combined drug column under internal pressure and temperature load all appeared in the transition section,and the maximum displacement of the cylindrical section was not much different from the cylindrical section under temperature load,and the stress and strain on the cylindrical section of the combined drug column under internal pressure load did not change much,and the maximum stress and strain on the transition section increased with the increase of length.The research content of this paper can provide a certain reference for the design of solid rocket motor charge and the study of internal ballistic performance.