Simulation Of Working Processof SRM With Complex Grain Based On Porous Media Model

The simulation of the working process of a solid rocket motor can effectively,quickly and economically obtain the real-time information such as the internal flow details of the engine and the internal ballistic curve.It also plays an important role in predicting engine performance and optimizing design.Coveredcharge and defective charge in the solid rocket motor is very common,andthe work process is well concerned by domestic and foreign experts and scholars,therefore,it is of great significance to the study of its working process and simulation method.The combination method of Level-set and porous medium model(LSPM)can simulate the working process of the solid rocket motor with complex charge,however,there are some limitations in the calculation of the charge with coating and the charge with internal defects.In this paper,based on the idea of porous media model,combined with the Level-set method,the method of interface recognition with cladding and internal defects based on LSPM is developed,which makes the LSPM algorithm more perfect.The following arethe contents:(1)The method of identifying the interface of thecoat and the internal defects is established.Combined with the Level-set method and the porous media model,the combustion surface regressionand working process in the engine of coated charge and charge with internal defects are simulated.It expands the applicability of the LSPMon transient inflow calculation of SRM.(2)A variety of models are selected to verify the interface area and internal flow field of the developed interface identification method with coat and internal defects.From the aspects of interface shape,interface area and combustion chamber pressure,it is verified that the improved LSPM has higher accuracy and versatility.(3)Based on the improved LSPM,the phenomenon of vortex shedding during the operation of a large aspect ratio solid rocket motor has been studied,the numerical verification proves the influence of temperature on the response frequency,and the two time combustion surface for the quasi-steady state are also be calculated,analyze the difference between the transient and quasi-steady state calculation results.(4)Based on the LSPM and the improved LSPM,the numerical simulation of the working process of the finocylgrain motor with surface crack and internal bubble has been carried out respectively.The analysis is conductedfrom aspect of internal ballistic curve and internal flow details,and the combustion chamber pressure of the engine is compared under the transient and quasi steady state calculations.The improved LSPM provides a new method for simulating the working process of the complex grain engine with coating and internal defect,which lays a good foundation for the calculation of transient internal flow field of complex charge.