Plate-Fin Surface Optimisation Using Direct-Sizing

The direct-sizing of heat exchangers applies to that class of heat exchanger in which the local geometry of the core is the same everywhere. Many of our best performing exchangers possess this property. Previous papers discussing this topic were published by Smith (1994, 1997a). Optimisation of rectangular offset strip-fin (ROSF) surfaces involves varying plate spacing b, cell pitch c, and strip-length x in a logical manner. The Manglik and Bergles correlations for flow-friction and heat transfer of ROSF surfaces permits such optimisation. The design procedure which follows applies to a two-stream contraflow exchanger assuming perfect gases.