Example problem 3 is designed to expose you to the considerations involved in performing 3-dimensional geometry modeling and subsequent thermal analyses. Towards this end, we will examine the problem of a 3-dimensional iron cube with liquid mercury flowing in a channel along one side. This problem will require the use of advection for the transfer of thermal energy with the flow of the liquid mercury. The assumption of convective resistance being negligible due to its high thermal conductivity is acceptable since the advective fluid is liquid metal. The finite element mesh required needs to be fine enough to handle the large temperature difference between the advective fluid and the iron cube.