If you describe what it is and what you want to simulate, you may get more replies from people who know CFD well but not what Peltier device is
Peltier device is also known as a TEC thermal electric cooler. It is a heat pump that pushes heat between two ceramic plates when current is present. I have a system comprised of part to be heated, Peltier device, and heat sink. I would like to know how temperature of the part is changing when different current is applied. In the past BRNI was considering developing this feature in CFDesign but I am not sure if it was ever implemented.