Laser diagnostics of transverse turbulent jets

Experiments were conducted in a low-speed wind tunnel to understand the influence of nozzle geometry on the flow characteristics of incompressible air jets injected normal to a free stream. Jets issuing from circular and noncircular nozzles, with exit Reynolds number in the range of 4500 to 9200 and velocity ratios from 3.8 to 7.7, are investigated. Measurements, in the zone of established flow, are carried out by laser light sheet flow visualization coupled with image processing and laser Doppler anemometry techniques. Results show that with increasing aspect-ratio of the nozzles the jet penetration increases and carries stronger bound vortex-pairs compared with the circular case. The deflected circular and square jets exhibit similar flow characteristics.