Infrared Thermography Study of Heat Transfer in an Array of Round Jets

The paper describes a study of convective heat transfer in a multiple-jet systems composed of round nozzles. The application concerned is the fast cooling of moving strip. The experimental approach involves the application of infrared thermography associated with the steady-state heated foil technique. The study aims to determine the effect on the average heat transfer coefficient of the jet Reynolds number in the range 40000 to 85000, the normalised nozzle to strip standoff distance Z/D from 2 to 10 and the normalised nozzle spacing W/D from 2 to 5. The geometrical nozzle arrangements tested include staggered and non-staggered configuration. The experimental findings are compared with an existing correlation; deviations, which are observed at small Z/D-values may reach 30%