Jet impingement heat transfer from lobed nozzles

The paper presents an experimental investigation of heat transfer obtained with impinging gas jets. Lobed nozzles are tested. The study parameters are the lobe geometry, the jet Reynolds number, Re, and the normalised standoff distance, z/D. The quantitative infrared thermography associated with the thermofoil technique is applied. At high Reynolds number (Re ≥ 15,000)) and small normalised standoff (z/D ≤ 1), the three-lobe nozzle affords performance better than the other nozzles. As the normalised standoff distance increases and exceeds z/D = 7, the 4-lobe yields better performance.