Study on Temperature Oscillation Phenomenon in FEM Numerical Simulation

The reasons of temperature field oscillation in numerical simulation are studied in this paper by theoretical analysis and simple calculation examples. The temperature derivative of an actual temperature field is continuous, but after FEM discretization, temperature derivative is not continuous on the both side of inner boundaries. It means heat flux vectors flowing in and out an inner boundary are not equal, which lead to temperature oscillation of numerical simulation result. After programing verification, it shows that replacing coordinate heat capacity matrix by lumped heat capacity matrix can reduce temperature oscillation effectively.