HEAT TRANSFER AND PRESSURE DROP CHARACTERISTICS OF CROSS FLOW OF AIR OVER A CIRCULAR TUBE IN ISOLATION AND/OR IN A TUBE BANK

摘要

Circular tube banks are probably the most common heat transfer surfaces, particularly in shell-and-tube heat exchangers. The fluid flow is ideally normal to the tubes. The most usual tube arrays are staggered and inline, although other arrangements are possible. The flow converges in the inter-tube spaces inside a bank and forms a highly turbulent flow over the inner tubes. The recirculation region in the rear of an inner tube is smaller than in a single tube. The situation is governed by the relative pitches and the bank geometry. The more compact a bank is, the larger is the difference from the single-tube situation. Some differences depend on the number of longitudinal rows because of the inlet-outlet effects [1].