Three-Dimensional Turbulent Wall Jets

2009 ◽  
Author(s):  
M. Agelinchaab ◽  
M. F. Tachie
Keyword(s):  
Reynolds Number ◽  
Turbulence Intensity ◽  
Large Scale ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Wall Jets ◽  
Turbulent Statistics ◽  
Turbulent Wall Jets ◽  
The Mean ◽  
Turbulent Wall

Particle image velocimetry (PIV) measurements were carried out on generic three-dimensional turbulent wall jets. The wall jets were created from a long circular pipe at Reynolds number based on the jet exit velocity (Uj) and inside diameter of pipe (d) of Rej = Ujd/v = 7680 to 19500. The profiles of the mean velocities, turbulence intensities and Reynolds shear stresses in the streamwise/wall-normal and streamwise/lateral planes are presented. Consistent with previous results, the profiles of the mean velocities and turbulent statistics are independent of Reynolds number. The mean velocity attained self-similarity before the turbulence quantities. The decay rate and spread rates obtained in the present study fall in between the values reported in previous studies. The contours of the two-point velocity correlations in the inner region of the 3D wall jet are qualitatively similar to those reported in boundary layer studies. The results from proper orthogonal analysis revealed that large scale structures are largely responsible for the distribution of the streamwise turbulence intensity and Reynolds shear stresses than the distribution of the wall-normal turbulence intensity.

Characteristics of 3D Turbulent Wall Jets and Offset Jets With Small Offset Ratios

2009 ◽  
Author(s):  
M. Agelinchaab ◽  
M. F. Tachie
Keyword(s):  
Three Dimensional ◽  
Symmetry Plane ◽  
Shear Stresses ◽  
Wall Jets ◽  
Particle Image Velocimetry Technique ◽  
Image Velocimetry ◽  
Turbulent Wall Jets ◽  
The Mean ◽  
Turbulent Wall ◽  
Proper Orthogonal

This paper reports an experimental study of turbulent three-dimensional generic wall jets and offset jets. The jets were created from a long circular pipe. A particle image velocimetry technique was used to conduct velocity measurements in the symmetry plane of the jet. From these measurements, the salient features of the flows are reported in terms of the mean velocities, turbulence intensities and Reynolds shear stresses. The energy spectra and profiles of reconstructed turbulence intensities and Reynolds shear stresses from low order proper orthogonal decomposition modes are also reported.

Mean and Turbulence Characteristics of a Class of Three-Dimensional Wall Jets—Part 2: Turbulence Characteristics

1991 ◽  
Vol 113 (4) ◽  
pp. 629-634 ◽  
Author(s):  
G. Padmanabham ◽  
B. H. Lakshmana Gowda
Keyword(s):  
Three Dimensional ◽  
Flow Characteristics ◽  
Shear Stresses ◽  
Normal Stresses ◽  
Mean Flow ◽  
Wall Jets ◽  
Turbulence Characteristics ◽  
Turbulent Wall Jets ◽  
The Mean ◽  
Turbulent Wall

The mean flow characteristics of three-dimensional, incompressible, isothermal turbulent wall jets generated from orifices having the shapes of various segments of a circle are presented in Part 1 of this paper. In this part, the turbulence characteristics are presented. Turbulence quantities measured include normal stresses and Reynolds shear stresses in the characteristic-decay and in the radial-decay regions of the wall jets investigated. These results are compared with those available for two-dimensional and three-dimensional wall jets. The presence of counter-gradient regions and the feature of “energy reveral” are discussed.

scholarly journals Erratum for “Three-Dimensional Turbulent Wall Jets”

1974 ◽  
Vol 100 (12) ◽  
pp. 1849-1849
Author(s):  
Nallamuthu Rajaratnam ◽  
Bidya Sagar Pani
Keyword(s):  
Three Dimensional ◽  
Wall Jets ◽  
Turbulent Wall Jets ◽  
Turbulent Wall

Flow Characteristics of Three-Dimensional Curved Wall Jets on a Cylinder

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Mirae Kim ◽  
Hyun Dong Kim ◽  
Eunseop Yeom ◽  
Kyung Chun Kim
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Turbulence Intensity ◽  
Flow Separation ◽  
Reynolds Shear Stress ◽  
Three Dimensional ◽  
Cylinder Surface ◽  
Cylinder Wall ◽  
Wall Jet ◽  
Wall Jets

Three-dimensional (3D) curved wall jets are a significant topic in various applications related to local heat and mass transfer. This study investigates the effects of the impinging angle and Reynolds number with a fixed distance from the nozzle to the surface of a cylinder. The particle image velocimetry (PIV) method was used to measure the mean streamwise velocity profiles, which were normalized by the maximum velocity along the centerline of the impinging jet onto the cylinder. After the impingement of the circular jet, a 3D curved wall jet develops on the cylinder surface due to the Coanda effect. At a given Reynolds number, the initial momentum of the wall jet increases, and flow separation occurs further downstream than in normal impingement as the impinging angle increases. At a given impinging angle, flow separation is delayed with increasing Reynolds number. A self-preserving wall jet profile was not attained in the 3D curved wall jet. The turbulence intensity and the Reynolds shear stress were obtained to analyze the turbulence characteristics. The radial turbulence intensity showed similar tendencies to a two-dimensional (2D) curved wall jet, but the streamwise turbulence intensity was dissimilar. The Reynolds shear stress decreases downstream of the cylinder wall due to the decreased velocity and centrifugal force.

Three-Dimensional Turbulent Wall Jets

1974 ◽  
Vol 100 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Nallamuthu Rajaratnam ◽  
Bidya Sagar Pani
Keyword(s):  
Three Dimensional ◽  
Wall Jets ◽  
Turbulent Wall Jets ◽  
Turbulent Wall
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