Laminar and Turbulent Boundary Layers on Moving, Nonisothermal Continuous Flat Surfaces

1982 ◽  
Vol 104 (4) ◽  
pp. 707-714 ◽  
Author(s):  
A. Moutsoglou ◽  
A. K. Bhattacharya
Keyword(s):  
Heat Transfer ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Moving Plate ◽  
Flat Surfaces ◽  
Eddy Diffusivities ◽  
Stress Surface ◽  
Continuous Plate ◽  
Surface Temperature Variation ◽  
Good Agreement

The heat-transfer characteristics of buoyancy-affected laminar and turbulent boundary layers on nonisothermal continuous flat surfaces that move steadily through a quiescent ambient fluid are studied analytically. Both cooling and heating of the continuous plate which is moving upward or downward in a horizontal, vertical, or inclined direction are considered. A mixing length model for the eddy diffusivities of momentum and heat based on an extension of the Van Driest model is employed in the turbulent boundary layers. Numerical results, such as wall shear stress, surface heat-transfer rate, and surface temperature variation, are presented for various Reynolds and Grashof numbers for fluids with a Prandtl number of 0.7, for both laminar and turbulent boundary layers. A good agreement is found between the analytical and experimental results for friction factor in turbulent boundary layer over an isothermal, continuous moving plate.

Effects of Embedded Vortices on Film-Cooled Turbulent Boundary Layers

1989 ◽  
Vol 111 (1) ◽  
pp. 71-77 ◽  
Author(s):  
P. M. Ligrani ◽  
A. Ortiz ◽  
S. L. Joseph ◽  
D. L. Evans
Keyword(s):  
Heat Transfer ◽  
Boundary Layers ◽  
Film Cooling ◽  
Free Stream ◽  
Flow Behavior ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Turbulent Boundary Layers ◽  
Stream Velocity ◽  
Longitudinal Vortices

Heat transfer effects of longitudinal vortices embedded within film-cooled turbulent boundary layers on a flat plate were examined for free-stream velocities of 10 m/s and 15 m/s. A single row of film-cooling holes was employed with blowing ratios ranging from 0.47 to 0.98. Moderate-strength vortices were used with circulating-to-free stream velocity ratios of −0.95 to −1.10 cm. Spatially resolved heat transfer measurements from a constant heat flux surface show that film coolant is greatly disturbed and that local Stanton numbers are altered significantly by embedded longitudinal vortices. Near the downwash side of the vortex, heat transfer is augmented, vortex effects dominate flow behavior, and the protection from film cooling is minimized. Near the upwash side of the vortex, coolant is pushed to the side of the vortex, locally increasing the protection provided by film cooling. In addition, local heat transfer distributions change significantly as the spanwise location of the vortex is changed relative to film-cooling hole locations.

Temperature-Invariant Scaling for Compressible Turbulent Boundary Layers with Wall Heat Transfer

2017 ◽  
Vol 39 (11) ◽  
pp. 923-932 ◽  
Author(s):  
Mostafa Safdari Shadloo ◽  
Abdellah Hadjadj ◽  
Fazle Hussain
Keyword(s):  
Heat Transfer ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Wall Heat Transfer

A Mixing-Length Model for the Prediction of Convex Curvature Effects on Turbulent Boundary Layers

1984 ◽  
Vol 106 (1) ◽  
pp. 142-148 ◽  
Author(s):  
E. W. Adams ◽  
J. P. Johnston
Keyword(s):  
Heat Transfer ◽  
Layer Thickness ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Radius Of Curvature ◽  
Data Sets ◽  
Mixing Length ◽  
Flat Wall ◽  
Curvature Effects ◽  
Layer Thickness Ratio

A mixing-length model is developed for the prediction of turbulent boundary layers with convex streamwise curvature. For large layer thickness ratio, δ/R > 0.05, the model scales mixing length on the wall radius of curvature, R. For small δ/R, ordinary flat wall modeling is used for the mixing-length profile with curvature corrections, following the recommendations of Eide and Johnston [7]. Effects of streamwise change of curvature are considered; a strong lag from equilibrium is required when R increases downstream. Fifteen separate data sets were compared, including both hydrodynamic and heat transfer results. In this paper, six of these computations are presented and compared to experiment.

Recent Developments in Calculation Methods for Turbulent Boundary Layers With Pressure Gradients and Heat Transfer

1966 ◽  
Vol 33 (2) ◽  
pp. 429-437 ◽  
Author(s):  
J. C. Rotta
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Temperature Distribution ◽  
Velocity Profile ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Pressure Gradients ◽  
Calculation Methods ◽  
Recent Developments ◽  
Incompressible Boundary

A review is given of the recent development in turbulent boundary layers. At first, for the case of incompressible flow, the variation of the shape of velocity profile with the pressure gradient is discussed; also the temperature distribution and heat transfer in incompressible boundary layers are treated. Finally, problems of the turbulent boundary layer in compressible flow are considered.

Equilibrium-Turbulent Boundary Layer Prediction for a Proposed Prandtl Mixing Length Distribution

1968 ◽  
Vol 10 (5) ◽  
pp. 426-433 ◽  
Author(s):  
F. C. Lockwood
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layers ◽  
Length Distribution ◽  
Momentum Equation ◽  
Turbulent Boundary Layers ◽  
Mixing Length ◽  
Good Agreement

The momentum equation is solved numerically for a suggested ramp variation of the Prandtl mixing length across an equilibrium-turbulent boundary layer. The predictions of several important boundary-layer functions are compared with the equilibrium experimental data. Comparisons are also made with some recent universal recommendations for turbulent boundary layers since the equilibrium experimental data are limited. Good agreement is found between the predictions, the experimental data, and the recommendations.

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