Local heat transfer distribution between smooth flat surface and impinging incompressible air jet from a chevron nozzle

Influence of chevron nozzle on local heat transfer distribution over a flat plate impinged by incompressible jets is studied for Reynolds numbers of 28,000, 35,000 and 40,000. Ten different chevron nozzle configurations are studied with a pipe diameter of 10.8 mm. Thin metal foil technique is used with IR camera to measure the wall temperature at nozzle to plate distances (z/d) from 1 to 10. An increase in the local Nusselt number by 26-38% compared to that with circular pipe is measured. It is observed that N10 nozzle (with number of chevron tips n = 8 and chevron tip angle θ = 10°) provides best heat transfer performance. A correlation for the average heat transfer is proposed in present study. A multiplication factor is also introduced to predict local Nusselt number for N10 nozzle.