Calculation of Turbulent Wall Jets With an Algebraic Reynolds Stress Model

1980 ◽  
Vol 102 (3) ◽  
pp. 350-356 ◽  
Author(s):  
M. Ljuboja ◽  
W. Rodi
Keyword(s):  
Reynolds Stress ◽  
Reynolds Stress Model ◽  
Transport Equations ◽  
Turbulent Shear ◽  
Wall Jet ◽  
Wall Jets ◽  
Mean Velocity ◽  
Empirical Constant ◽  
Turbulent Wall Jets ◽  
Turbulent Wall

A modified version of the k-ε turbulence model is developed which predicts well the main features of turbulent wall jets. The model relates the turbulent shear stress to the mean velocity gradient, the turbulent kinetic energy k, and the dissipation rate ε by way of the Kolmogorov-Prandtl eddy viscosity relation and determines k and ε from transport equations. The empirical constant in the Kolmogorov-Prandtl relation is replaced by a function which is derived by reducing a model form of the Reynolds stress transport equations to algebraic expressions, retaining the wall damping correction to the pressure-strain model used in these equations. The modified k-ε model is applied to a wall jet in stagnant surroundings as well as to a wall jet in a moving stream, and the predictions are compared with experimental data. The agreement is good with respect to most features of these flows.

Prediction of Horizontal and Vertical Turbulent Buoyant Wall Jets

1981 ◽  
Vol 103 (2) ◽  
pp. 343-349 ◽  
Author(s):  
M. Ljuboja ◽  
W. Rodi
Keyword(s):  
Heat Flux ◽  
Vertical Wall ◽  
Transport Equations ◽  
Turbulent Shear ◽  
Wall Jets ◽  
Flux Transport ◽  
Mean Velocity ◽  
Empirical Constant ◽  
Turbulent Shear Stress ◽  
Semi Empirical

A buoyancy-extended version of the k – ε turbulence model is described which predicts well the main features of turbulent buoyant wall jets. The model relates the turbulent shear stress and heat flux to the mean velocity and temperature gradients respectively and to the turbulent kinetic energy k and the dissipation rate ε by way of the Kolmogorov-Prandtl eddy viscosity/diffusivity relation and determines k and ε from semi-empirical transport equations. The empirical constant cμ in the Komogorov-Prandtl expression and the usually constant turbulent Prandtl number σt are replaced by functions which are derived by reducing model forms of the Reynolds-stress and heat-flux transport equations to algebraic expressions, retaining the buoyancy terms and the wall-damping correction to the pressure-strain/scrambling model in these equations. The extended k – ε model is applied to buoyant wall jets along a horizontal wall and to α plume developing along a vertical wall. The predictions are compared with experimental data whenever possible and are found to be in good agreement with the data.

Heat Transfer to Plane Turbulent Wall Jets

1963 ◽  
Vol 85 (3) ◽  
pp. 209-213 ◽  
Author(s):  
G. E. Myers ◽  
J. J. Schauer ◽  
R. H. Eustis
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Temperature Distribution ◽  
Wall Jet ◽  
Analytical Prediction ◽  
Two Dimensional ◽  
Heat Transfer Characteristics ◽  
Wall Jets ◽  
Turbulent Wall Jets ◽  
Turbulent Wall

The heat-transfer characteristics of two-dimensional, incompressible, turbulent wall jets are discussed. An analytical prediction is made for the local Stanton number and data are presented for a step wall temperature distribution. The method for extending these data to arbitrary heating conditions is shown. Temperature surveys in the wall jet boundary layer are also presented.

A Reynolds stress model of turbulence and its application to thin shear flows

1972 ◽  
Vol 52 (4) ◽  
pp. 609-638 ◽  
Author(s):  
K. Hanjalić ◽  
B. E. Launder
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Reynolds Stress ◽  
Reynolds Stress Model ◽  
Energy Dissipation Rate ◽  
Solution Procedure ◽  
Transport Equations ◽  
Turbulent Shear ◽  
Turbulence Energy ◽  
Boundary Layer Flows

The paper provides a model of turbulence which effects closure through approximated transport equations for the Reynolds stress tensor$\overline{u_iu_j}$and for the turbulence energy-dissipation rate ε. In its most general form the model thus entails the solution of seven transport equations for turbulence quantities but contains only six constants to be determined by experiment. It is demonstrated that the proposed approximation to the pressure-rate-of-strain correlations leads to satisfactory predictions of the component stress levels in plane homogeneous turbulence, including the non-equality of the lateral and transverse normal-stress components.For boundary-layer flows a simpler version of the model is derived wherein transport equations are solved only for the shear stress$-\overline{u_1u_2}$the turbulence energy κ and ε. This model has been incorporated in the numerical solution procedure of Patankar & Spalding (1970) and applied to the prediction of a number of boundary-layer flows including examples of flow remote from walls, those developing along one wall and those confined within ducts. Three of the flows are strongly asymmetric with respect to the surface of zero shear stress and here the turbulent shear stress does not vanish where the mean rate of strain goes to zero. In most cases the predicted profiles and other quantities accord with the data within the probable accuracy of the measurements.

scholarly journals Scaling mean velocity in two-dimensional turbulent wall jets

2020 ◽  
Vol 891 ◽  
Author(s):  
Abhishek Gupta ◽  
Harish Choudhary ◽  
A. K. Singh ◽  
Thara Prabhakaran ◽  
Shivsai Ajit Dixit
Keyword(s):  
Two Dimensional ◽  
Wall Jets ◽  
Mean Velocity ◽  
Turbulent Wall Jets ◽  
Image Position ◽  
Turbulent Wall

Experimental Investigation of Curvature Effects on Turbulent Wall Jets

1969 ◽  
Vol 73 (707) ◽  
pp. 977-981 ◽  
Author(s):  
K. Sridhar ◽  
P. K. C. Tu
Keyword(s):  
Plane Surface ◽  
Wall Jet ◽  
Wall Jets ◽  
Curvature Effects ◽  
The Past ◽  
Turbulent Wall Jets ◽  
Turbulent Jet Flow ◽  
The Mean ◽  
Turbulent Wall ◽  
Complementary Study

The phenomenon of a jet emerging tangentially to a wall and flowing along the surface of the wall has long been known as a wall jet. Plane and curved wall jets have been investigated by many researchers in the past. In spite of many investigations in this field, a reasonably complete understanding of the curvature effects on the turbulent wall jet has not been achieved. This investigation, therefore, was intended to serve as a complementary study of curvature effects. Experiments were performed with a two-dimensional turbulent jet flow over a plane surface and over circular convex and concave surfaces of various radii in still air. The study was limited to the mean properties of the flow and was not concerned with the momentum loss on the surface.

Mean and Turbulence Characteristics of a Class of Three-Dimensional Wall Jets—Part 1: Mean Flow Characteristics

1991 ◽  
Vol 113 (4) ◽  
pp. 620-628 ◽  
Author(s):  
G. Padmanabham ◽  
B. H. Lakshmana Gowda
Keyword(s):  
Three Dimensional ◽  
Flow Characteristics ◽  
Experimental Investigations ◽  
Wall Jet ◽  
Mean Flow ◽  
Wall Jets ◽  
Mean Velocity ◽  
Turbulence Characteristics ◽  
Turbulent Wall ◽  
And Behavior

This paper reports experimental investigations on mean and turbulence characteristics of three-dimensional, incompressible, isothermal turbulent wall jets generated from orifices having the shapes of various segments of a circle. In Part 1, the mean flow characteristics are presented. The turbulence characteristics are presented in Part 2. The influence of the geometry on the characteristic decay region of the wall jet is brought out and the differences with other shapes are discussed. Mean velocity profiles both in the longitudinal and lateral planes are measured and compared with some of the theoretical profiles. Wall jet expansion rates and behavior of skin-friction are discussed. The influence of the geometry of the orifice on the various wall jet properties is presented and discussed. Particularly the differences between this class of geometry and rectangular geometries are critically discussed.

scholarly journals Curvature Effects on Two-dimensional Turbulent Wall Jets along Concave Surfaces

1983 ◽  
Vol 26 (222) ◽  
pp. 2074-2080 ◽  
Author(s):  
Ryoji KOBAYASHI ◽  
Nobuyuki FUJISAWA
Keyword(s):  
Two Dimensional ◽  
Wall Jets ◽  
Curvature Effects ◽  
Turbulent Wall Jets ◽  
Turbulent Wall
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