Solid Rocket Motor Cooling Impact Process Numerical Simulation

The study object of this dissertation is the solid rocket motor cool-air impact process. A two-dimensional, three-dimensional flow field model and structure model was established, the cold air impact process is simulated using fluid-structure coupling method, the main work includes:(1) The SRM cold-air impacting system model is established, analyzing the mechanism of the impact of cold flow, deducing the shock wave propagation in the cold-air impacting process. According to the solid rocket motor propellant viscoelasticity, a linear viscoelastic constitutive equation of the grain is obtained. Studying the data exchange method of fluid-structure coupling computation, for the flow field change caused by propellant deformation in SRM cold-air impacting, the dynamic mesh technology was adopted.(2) SRM air impact simulation of one-dimensional, two-dimensional, three-dimensional flow field model were established in the flow field simulation, the shock wave propagation regularity and characteristics of flow field distribution in the cool-air impacting process were obtained, the results show that the shock wave characteristics using each of the three methods are substantially the same, the original shock wave and the reflected shock wave characteristics are coincide with the theoretical solutions. A acoustic oscillation phenomenon exists in the shock wave spreading process is discovered. Through the comparison of two dimensional and three dimensional flow field calculation, the acoustic oscillation phenomenon of the two dimensional flow field calculation results is more obvious.(3) the propellant was regarded as a viscoelastic material, the structural dynamics analysis for solid propellant is based on finite element method, the grain was analysis using the FEM software, get the grain stress strain distribution and found the easy failure location.(4) SRM cool-air impacting process was simulated using a two-way fluid-structure coupling calculation method. The pressure of the flow field was transmitted to the structure field, displacement obtained by the structure computation was transfer to flow field, using dynamic mesh technique to change the flow field. The mechanical response of the grain under the impact process was obtained. Find the propellant maximum deformation, stress and strain position.