Analytical Study of Laminar Boundary Layers with Non-Uniform Main Stream Velocity and Wall Temperature

1985 ◽  
Vol 10 (4) ◽  
Author(s):  
P. Singh ◽  
S.A. Raj
Keyword(s):  
Boundary Layers ◽  
Wall Temperature ◽  
Analytical Study ◽  
Stream Velocity ◽  
Main Stream ◽  
Laminar Boundary Layers

A Reference Temperature Method for Compressible Laminar Boundary Layers

1973 ◽  
Vol 2 (4) ◽  
pp. 201-204
Author(s):  
R. Camarero
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Reference Temperature ◽  
Integral Approach ◽  
Pressure Gradients ◽  
Two Dimensional ◽  
Laminar Boundary Layers ◽  
Temperature Method ◽  
Compressibility Effects

A calculation procedure for the solution of two-dimensional and axi-symmetric laminar boundary layers in compressible flow has been developed. The method is an extension of the integral approach of Tani to include compressibility effects by means of a reference temperature. Arbitrary pressure gradients and wall temperature can be specified. Comparisons with experiments obtained for supersonic flows over a flat plate indicate that the method yields adequate results. The method is then applied to the solution of the boundary layer on a Basemann inlet.

Correlated incompressible and compressible boundary layers

1949 ◽  
Vol 200 (1060) ◽  
pp. 84-100 ◽  
Keyword(s):  
Boundary Layer ◽  
Exact Solution ◽  
Boundary Layers ◽  
Absolute Temperature ◽  
Stream Velocity ◽  
Main Stream ◽  
Boundary Layer Equations ◽  
Compressible Boundary Layers ◽  
Incompressible Boundary ◽  
Similar Solutions

The boundary-layer equations for a compressible fluid are transformed into those for an incompressible fluid, assuming that the boundary is thermally insulating, that the viscosity is proportional to the absolute temperature, and that the Prandtl number is unity. Various results in the theory of incompressible boundary layers are then taken over into the compressible theory. In particular, the existence of ‘similar’ solutions is proved, and Howarth’s method for retarded flows is applied to determine the point of separation for a uniformly retarded main stream velocity. A comparison with an exact solution is used to show that this method gives a closer approximation than does Pohlhausen’s.

Analytical Study of Laminar Boundary Layers near Blunted Bodies

2020 ◽  
Vol 12 (1) ◽  
pp. 60-69
Author(s):  
V. N. Bulgakov ◽  
V. P. Kotenev ◽  
Iu. S. Ozhgibisova
Keyword(s):  
Boundary Layers ◽  
Analytical Study ◽  
Laminar Boundary Layers

Three-dimensional laminar boundary layers in crosswise pressure gradients

1974 ◽  
Vol 66 (4) ◽  
pp. 641-655 ◽  
Author(s):  
J. H. Horlock ◽  
A. K. Lewkowicz ◽  
J. Wordsworth
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Boundary Layers ◽  
Free Stream ◽  
Three Dimensional ◽  
Cross Flow ◽  
Free Stream Velocity ◽  
Stream Velocity ◽  
Laminar Boundary Layers ◽  
The Cross

Two attempts were made to develop a three-dimensional laminar boundary layer in the flow over a flat plate in a curved duct, establishing a negligible streamwise pressure gradient and, at the same time, an appreciable crosswise pressure gradient.A first series of measurements was undertaken keeping the free-stream velocity at about 30 ft/s; the boundary layer was expected to be laminar, but appears to have been transitional. As was to be expected, the cross-flow in the boundary layer decreased gradually as the flow became progressively more turbulent.In a second experiment, at a lower free-stream velocity of approximately 10 ft/s, the boundary layer was laminar. Its streamwise profile resembled closely the Blasius form, but the cross-flow near the edge of the boundary layer appears to have exceeded that predicted theoretically. However, there was a substantial experimental scatter in the measurements of the yaw angle, which in laminar boundary layers is difficult to obtain accurately.

Thermal Radiation in Laminar Boundary Layers on Continuous Moving Surfaces

1974 ◽  
Vol 96 (1) ◽  
pp. 32-36 ◽  
Author(s):  
C. A. Rhodes ◽  
C. C. Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
Boundary Layers ◽  
Analytical Study ◽  
Radiation Flux ◽  
Radiation Heat Transfer ◽  
Normal Velocity ◽  
Radiation Heat ◽  
Flat Plates ◽  
Laminar Boundary Layers

Thermal radiation heat transfer is studied in boundary layers on continuous moving surfaces. An analytical study is performed for two-dimensional laminar flow of an absorbing and emitting fluid. Solutions were obtained for limiting conditions of optically thin and thick boundary layers. Comparisons indicate that the radiation flux in these boundary layers is less than that for flow over semi-infinite flat plates for optically thin flows. The radiation contribution becomes more nearly equal as optical thickness increases. The normal velocity induced in the free stream by the wall motion significantly affects the radiation heat transfer.

An Aspect of Heat Transfer in Accelerating Turbulent Boundary Layers

1969 ◽  
Vol 91 (2) ◽  
pp. 229-234 ◽  
Author(s):  
B. E. Launder ◽  
F. C. Lockwood
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Thermal Boundary Layer ◽  
Free Stream ◽  
Turbulent Boundary Layers ◽  
Stanton Number ◽  
Stream Velocity ◽  
Velocity Boundary Layer ◽  
Positive Exponent

Theoretical consideration indicates that, in an accelerated turbulent flow, the thermal boundary layer may penetrate significantly beyond the edge of the velocity boundary layer. This effect may contribute in part to the marked decrease in Stanton number which has been reported in accelerated turbulent boundary layers. This paper presents theoretical solutions to turbulent velocity and thermal boundary layers in flow between converging planes where the wall temperature varies as the free-stream velocity raised to a positive exponent. The solutions clearly illustrate that, as the wall-temperature variation is made less rapid, the thermal boundary layer penetrates progressively further beyond the velocity boundary layer, causing the Stanton number to decrease.

Velocity Profiles in the Skewed Boundary Layers on Some Rotating Bodies in Axial Flow

1970 ◽  
Vol 37 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Y. Furuya ◽  
I. Nakamura
Keyword(s):  
Boundary Layers ◽  
Axial Flow ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
The Body ◽  
Stream Velocity ◽  
Main Stream ◽  
Rotating Speed ◽  
Incompressible Boundary ◽  
Rotating Bodies

Velocity distributions in incompressible boundary layers on the various rotating bodies in axial flow were investigated experimentally. The rotating bodies consisted of a cylinder with nose section of three forms. Tests were run with two Reynolds numbers and the ratio of peripheral velocity of the body to main-stream velocity was in the range 0–4. The centrifugal force of the rotation considerably affected the meridian velocity profiles. Momentum thicknesses calculated from a theory with assumption of the quasi-two-dimensional velocity profile agreed well with the experiments except in the case of high rotating speed. The local shearing stress in the rotating direction is discussed.

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