Free Stream Temperature wall boundary condition

emanuele

hello. I have an oven with some entries of warm air (313 k) and a steel chain inside of the oven. I want to simulate the heating of the chain, so in the wall panel for the chain i have activated convection thermal condition. The question is: what value should i use for " free stream temperature " ? I have some doubt because initial temperature inside the oven is 288 k, but it increases during the simulation for the effect of the flows of warm air. So can i put 288 k or not? Another queston is: How can i calculate appropriate value for heat transfer coefficient?

Thanks a lot Emanuele