Heat transfer and hydrodynamics of an array of round impinging jets with one-sided exhaust of the spent air

Abstract

The paper presents the results of an experimental investigation of local heat transfer at the surface blown by an array of round impinging jets with the spent air exhaust on one side. The experiments were carried out in the following range of parameters: f ̄ = 0.006–0.18 ; h d = 1–10 ; d = 1–5 mm; Re d = 1.1 × 10 3−17 × 10 3. Applicability of the collector relationships to calculate air distribution over the length of perforation, the jet flow and stalling flow velocity ratio and the coefficients of the total hydraulic resistance of the jet arrays, is considered. The channel technique is suggested to correlate the data on heat transfer in an array of impinging jets with one-sided exhaust of air. The validity and sufficient universality of this technique has been also confirmed by recalculation of the reported data. With power losses for air pumping through the system taken into account, the relationship has been established between the optimum open surface of perforation f ̄ opt and the relative spacing h L . Empirical relationships are suggested for calculation of heat transfer in an array of impinging jets with flow exhaust on one side.