Heat Transfer to a Ducted, Semiconfined Impinging Synthetic Air Jet

Heat transfer to confined impinging synthetic air jets is investigated experimentally. The influence of ducting on the cooling performance of synthetic air jets is of particular interest. Heat transfer to the jets is reported for a wide range of experimental parameters including nozzle to impingement surface spacings (0.5 to 5 jet diameters), Reynolds numbers (2000, 3000 and 4000) and non-dimensional Stroke lengths, L₀/D (10 15 and 20 respectively). A range of ducting outlet sizes were also investigated (1, 1.2, 1.4 jet diameters). It has been found that ducting can have the effect of reducing the turbulent mixing of the flow but overall enhances the rate of heat transfer to the jet at low H/D < 2. The largest ducting outlet of 1.4 jet diameters has also been shown to outperform the others across the whole range of variables tested.