In SW Flow Simulation I want to simulate an waterproof case and inside of the case there is a volume source of 10 W and air. On the outside of the case is water with 18°C. I want to see the maximal temperature of the volume source. If i simulate and plot the temperature of the air gets warm but the material of the case (PETG and Aluminum) is 18 °C inside and outside. Can someone help me with the setup of the simulation and its boundarys?