ABSTRACT
The unsteady surface element (USE) method is a boundary discretization method for solution of linear transient two-and three-dimensional heat transfer problems. Its development originated with the need to calculate interface temperatures and heat fluxes for similar and dissimilar geometries connected over a relatively small portion of their surface boundaries. Examples of bodies connected over a small area occur in contact conductance problems such as the case of two semi-infinite cylinders in contact over only a central circular region, as shown in Figure 12.1a. An example involving dissimilar geometries is the intrinsic thermocouple problem which involves a semi-infinite cylinder attached to a semi-infinite body (Figure 12.1b) or to an infinite plate (Figure 12.1c). Other related examples are those associated with the electrical contacts, cooling of electronic systems, fins, and conjugated problems.
