Numerical simulation of air arc impinging to chamber shell with multi-physical coupling method of fluid-thermal-structure

The air arc impinging to chamber shell during interruption current process were studied by experiments and numerical simulation. Firstly, strain characteristics of chamber shell were measured by the strain gauge, and the strain changing with times were lagging behind the pressure in arc chamber. Experiment strain results 0.0035 and 0.0025 were slightly smaller than the calculation results 0.0055 and 0.0035. Furthermore, the thermal field mathematics model of chamber shell was proposed, and it was found that there was a large temperature gradient in the thickness of the chamber shell. Lastly, stresses-strains of three kinds of coupling methods, which were the fluid-structure coupling, the thermal-structure coupling and the fluid-thermal-structure coupling were compared. It was confirmed that the mechanical stress was concentrated in the middle of the side wall, while the maximum thermal stress was distributed on the vent area. Total stress and total strain were not equal to the algebraic sum of mechanical field and thermal field. The effect of different fixed supports on the thermal field was greater than the effect on the fluid field, and outer side wall fixed support had minimal displacement.