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Experimental investigation of opposed jets discharging normally into a cross-stream

Published online by Cambridge University Press:  20 April 2006

K. N. Atkinson ,
Z. A. Khan  and
J. H. Whitelaw
K. N. Atkinson
Affiliation:
Imperial College of Science and Technology, Department of Mechanical Engineering, Fluids Section, London SW7 2BX
Z. A. Khan
Affiliation:
Imperial College of Science and Technology, Department of Mechanical Engineering, Fluids Section, London SW7 2BX
J. H. Whitelaw
Affiliation:
Imperial College of Science and Technology, Department of Mechanical Engineering, Fluids Section, London SW7 2BX
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Abstract

Detailed measurements are reported of mean-flow and turbulence characteristics of opposed jets discharging normally into a cross-flowing stream. They were obtained with pitch-to-diameter ratios of two and four, and for the limiting case of single opposed jets and for a separation of four jet diameters. Results are presented at downstream distances from two diameters from the plane of the jet centres.

The results for the symmetrically arranged jets show that the jets retain their identity for a velocity ratio of unity and pitch-to-diameter ratios of four and infinity. With a velocity ratio of 1·8, the single opposed jets bifurcate about a vertical plane to form two symmetric cores of mixed jet fluid. With the pitch-to-diameter ratio of two, the individual jets retain their identity and, in contrast with the results for a pitch-to-diameter ratio of four, where each jet divides to form two cores, only one core is formed for each jet. In general, the turbulence characteristics are determined by the mean flow, which is controlled largely by pressure forces.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 115 , February 1982 , pp. 493 - 504
Copyright
© 1982 Cambridge University Press

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