I'am doing an external flow analysis in vacuum. The problem statement is that Iam trying to find out the temperature distcribution on an assembly when a piece of Aluminum in the assembly is heated via PID control ie., controlled surface heat source of 40W and I would like to get some inputs on how to go about setting up boundary conditions
1. Heat condition in solids only option is chosen along with radiation ? Will this be sufficient to define a vacuum condition ? how is this different from choosing heat conditions in solids and then specifying the vacuum pressure under the fluids thermodynamic parameters ?
2. How do i input a surface heat source which is controlled (PID) based on the temperature of a solid body in that assembly ? I am not sure how the goal dependency for a surface heat source works ? Appreciate some help or examples on this.
3.Why do I get different results when I use a real wall boundary condition by specifying the intended temperature instead of the surface heat source ?
Any help would be greatly appreciated.