New ways of predicting heat-transfer performance

In the past, heat exchangers were designed using correlations derived from experimental data through dimensional analysis. These correlations essentially consisted of algebraic functions of resistance coefficients and local conditions. Recently, it has become increasingly possible to replace these correlations with computer models of heat transfer processes. For this purpose, the basic information is input into a computer program that solves the differential equations and calculates the heat flux at the wall for arbitrary boundary conditions. The following presents new computer models for two- and three-dimensional flows, which make it possible to forgo the costly experiments required for the establishment of correlation formulas.