Energy 2D: Interactive Heat Transfer Simulations
Energy 2D is an interactive heat transfer simulation program that models all three types of heat transfer (conduction, convection, and radiation). It allows the user to design "computational experiments" to test a hypothesis or solve a problem. Developed by Charles Xie at the Concord Consortium.

Charles Xie, Interactive Heat Transfer Simulations for Everyone, The Physics Teacher, Volume 50, Issue 4, pp. 237-240, 2012.