A rectangular heat source (that is almost as long as the edge of the upper compartment) and a round heat source are both at 80°C. At the left side there are two heat sinks set at 20°C. The entire boundary is insulative. The heat flux vectors (the rates of heat flow at given locations) appear to be much greater near the round heat source than near the rectangular one, indicating that temperature drops faster in the former case. The heat flux field in the case of the rectangular heat source appears to be uniform, with the temperature drops one degree at approximately the same distance away from the heat source. Can you figure out why there is such a difference? (Hint: Think about conservation of energy during heat flow.)

Graph Isotherm

Right-click to download this model

Developed by Charles Xie. © 2010- The Concord Consortium.