Cooling of a finned cylinder by a jet flow of air

A submerged slot jet of air is used as cooling system for an externally finned cylinder ensemble, heated by electric current. The cylinder ensemble is made with a stainless steel finned tube and a Teflon® bar as core. Five thermocouples, pressed inside the steel tube by the Teflon bar, measure the wall temperature in order to determine local and mean convective heat transfer coefficients. The local Nusselt number has its maximum on the impinging point and its minimum on the opposite position. The variation of the local and mean Nusselt number with the distance from the slot exit is investigated. An empirical expression is proposed to correlate the experimental data. The cooling with a jet flow of a finned cylinder realizes a higher heat transfer as compared to that of a smooth cylinder