Thermal And Thermal-Structural Couple Analysis Of The Rosette Carbon-Carbon Nozzle In SRM

This thesis is based on the research on "Thermal analysis and thermal-structurecouple analysis of the rosette carbon-carbon nozzle in solid rocket motor (SRM)"which is the fund project supported by China Aerospace Science & TechnologyCorporation. Flexible nozzle is one of the most important components used in SRM. Thenozzle is subjected to the cautery and concussion of the heat gas, so the thermal effectand related thermal-structure couple effect to the nozzle structure become theimportant factor affecting the load carrying capability of the nozzle. According to therequirement of the project research, the following investigation contents areaccomplished in this paper. Firstly, the stead-state thermal analysis is completed, and the temperaturedistribution is attained under the given thermal boundary conditions. Based ongeometry characteristic of the flexible nozzle and the main factor in the procedure ofthe thermal analysis, the axial symmetry FEM model is established and thetemperature distribution of the nozzle is evaluated. Next, on the basis of the steady-state thermal analysis, the thermal elastic-plasticanalysis of the thermal-structure couple is obtained in the axial symmetry loads. In thesteady-state thermal analysis, the boundary conditions of temperature and convectionon the surface of nozzle are axial symmetry, then the temperature distribution in thenozzle is axial symmetry naturally. So by treating the result of the steady-state thermalanalysis as the temperature loads of the couple analysis, and under the axial symmetryboundary conditions of inner pressure, the thermal stress distribution is computed asaxial symmetry problem so that obtaining precise result. At last, the thermal-structure analysis will be extended to three-dimensionalthermal-stress analysis in the cases of nonaxial symmetry loads. Thethree-dimensional FEM model is set up by using the geometry enantiomorphoussymmetry of the flexible nozzle, and the mechanics characteristics of the flexiblesupport can be simulated by the spring model on the sphere area. Thethree-dimensional steady-state temperature field of the flexible nozzle with fixsupport is evaluated, and then the thermal-structure couple elastic-plastic stress isanalyzed.