Computation of Parallel Convective Exchanges with Versatile Inlet/outlet Conditions Using Generalized Graetz Modes

Abstract. We propose and develop a functional minimization weak-formulation treatment of possibly complex applied input/output conditions which handles either convective, adiabatic, or prescribed temperature at the entrance or the exit of parallel convective exchangers. This formulation permits to re-cast realistic three-dimensional exchangers into a two-dimensional eigenvalue problem which is solved numerically using finite-element. This formulation is robust to mode truncation, offering a huge reduction in computational cost, and providing insight into the most contributing structure to exchanges and transfer. Several examples of exchangers are analyzed to test numerical convergence and illustrate the numerical efficiency of the approach.