A numerical and experimental investigation of the interactions between a non-uniform planar array of incompressible free jets

2004 ◽  
Vol 44 (4) ◽  
pp. 431-446 ◽  
Author(s):  
C. H. Isaac Manohar ◽  
T. Sundararajan ◽  
V. Ramjee ◽  
S. Sasi Kumar
Author(s):  
Ella M. Morris ◽  
Seyed S. Aleyasin ◽  
Neelakash Biswas ◽  
Mark F. Tachie

Abstract An experimental investigation of nozzle orientation effects on turbulent characteristics of elliptic triple free jets was carried out for three nozzle configurations. The first configuration had all three nozzles oriented along the minor plane (3_Minor), the next had two nozzles oriented along the minor plane and one along the major plane (2_Minor_1_Major) and the last configuration had one nozzle oriented along the minor plane and two along the major plane (1_Minor_2_Major). The experiments were conducted using modified contoured nozzles with a sharp linear contraction for a nozzle-to-nozzle distance of 4.1, a nozzle equivalent diameter of 9 mm and a Reynolds number of 10,000. The effects of nozzle orientation on the mean velocity, turbulence intensity and Reynolds shear stress were discussed. The velocity decay, jet spread, merging point, combined point and potential core length were used to characterize the effects of nozzle orientation on the mixing performance. The results show that the 3_Minor configuration had shorter potential core length and closer merging point location which are indicative of a faster mixing in the converging region. Two-point correlation, skewness and flatness factors were used to provide insight into the effects of nozzle orientation on turbulence structure and higher order turbulence statistics.


1992 ◽  
Vol 114 (2) ◽  
pp. 469-475
Author(s):  
J. Lepicovsky

An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprising finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence’s prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.


Author(s):  
J. Lepicovsky

An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprizing finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence’s prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.


2014 ◽  
Author(s):  
Shane Close ◽  
Victoria Adkins ◽  
Kandice Perry ◽  
Katheryn Eckles ◽  
Jill Brown ◽  
...  

2004 ◽  
Author(s):  
Mustapha Mouloua ◽  
Janan Smither ◽  
Robert C. Kennedy ◽  
Robert S. Kenned ◽  
Dan Compton ◽  
...  

2013 ◽  
Author(s):  
Sarah Edwards ◽  
Lindsey Brinker ◽  
Kathryn A. Bradshaw ◽  
Jennifer A. Munch ◽  
Rachel E. Brenner

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