Adiabatic Wall Effectiveness of a Turbulent Boundary Layer With Slot Injection

1976 ◽  
Vol 98 (2) ◽  
pp. 240-244 ◽  
Author(s):  
R. E. Mayle ◽  
F. C. Kopper
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Free Stream ◽  
Theoretical Work ◽  
Layer Growth ◽  
Stream Velocity ◽  
Adiabatic Wall ◽  
Velocity Flow ◽  
Hydrodynamic Boundary Layer ◽  
Boundary Layer Growth

An analysis is presented which extends the theoretical work of Weighardt and determines the adiabatic wall effectiveness of a turbulent boundary layer in a constant free-stream velocity flow heated or cooled by the discharge of a secondary fluid through a slot. A comparison of the analysis with the experimental results of Wieghardt is made and it is found that the streamwise decay in adiabatic wall effectiveness, except in the immediate region of the slot, may be explained by considering the thermal boundary layer growth within the hydrodynamic boundary layer.

Influence of Free-Stream Turbulence on Turbulent Boundary Layer Heat Transfer and Mean Profile Development, Part I—Experimental Data

1983 ◽  
Vol 105 (1) ◽  
pp. 33-40 ◽  
Author(s):  
M. F. Blair
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Flow ◽  
Free Stream ◽  
Full Range ◽  
Stream Velocity ◽  
Free Stream Turbulence ◽  
Turbulent Boundary Layer Flow ◽  
Layer Flow

An experimental research program was conducted to determine the influence of free-stream turbulence on zero pressure gradient, fully turbulent boundary layer flow. Connective heat transfer coefficients and boundary layer mean velocity and temperature profile data were obtained for a constant free-stream velocity of 30 m/s and free-stream turbulence intensities ranging from approximately 1/4 to 7 percent. Free-stream multicomponent turbulence intensity, longitudinal integral scale, and spectral distributions were obtained for the full range of turbulence levels. The test results with 1/4 percent free-stream turbulence indicate that these data were in excellent agreement with classic two-dimensional, low free-stream turbulence, turbulent boundary layer correlations. For fully turbulent boundary layer flow, both the skin friction and heat transfer were found to be substantially increased (up to ∼ 20 percent) for the higher levels of free-stream turbulence. Detailed results of the experimental study are presented in the present paper (Part I). A comprehensive analysis is provided in a companion paper (Part II).

Turbulent boundary-layer growth over a longitudinally curved surface

AIAA Journal ◽  
1975 ◽  
Vol 13 (11) ◽  
pp. 1448-1453 ◽  
Author(s):  
R. N. Meroney ◽  
P. Bradshaw
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Layer Growth ◽  
Curved Surface ◽  
Boundary Layer Growth

Velocity and Temperature Profiles in Turbulent Boundary Layers With Tangential Injection

1962 ◽  
Vol 84 (1) ◽  
pp. 45-54 ◽  
Author(s):  
R. A. Seban ◽  
L. H. Back
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Thermal Behavior ◽  
Boundary Layers ◽  
Film Cooling ◽  
Mass Velocity ◽  
Free Stream ◽  
Turbulent Boundary Layers ◽  
Temperature Profiles ◽  
Adiabatic Wall

Velocity and temperature profiles are presented for the turbulent boundary layer downstream of a tangential injection slot for the further clarification of the film-cooling problem. The profiles refer primarily to an injection mass velocity of 0.36 times that of the free stream; these and other auxiliary results demonstrate a complex hydrodynamic and relatively simple thermal behavior in which the temperature profiles appear to be similar in all cases. By using this correspondence together with the approximation of a fully developed hydrodynamic layer in most of the downstream region, it is possible to rationalize the adiabatic wall temperatures that have been presented previously.

scholarly journals The rough favourable pressure gradient turbulent boundary layer

2009 ◽  
Vol 641 ◽  
pp. 129-155 ◽  
Author(s):  
RAÚL BAYOÁN CAL ◽  
BRIAN BRZEK ◽  
T. GUNNAR JOHANSSON ◽  
LUCIANO CASTILLO
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Pressure Gradient ◽  
Rough Surface ◽  
Reynolds Stress ◽  
Friction Velocity ◽  
Free Stream ◽  
Stream Velocity ◽  
The Mean ◽  
Stress Profiles

Laser Doppler anemometry measurements of the mean velocity and Reynolds stresses are carried out for a rough-surface favourable pressure gradient turbulent boundary layer. The experimental data is compared with smooth favourable pressure gradient and rough zero-pressure gradient data. The velocity and Reynolds stress profiles are normalized using various scalings such as the friction velocity and free stream velocity. In the velocity profiles, the effects of roughness are removed when using the friction velocity. The effects of pressure gradient are not absorbed. When using the free stream velocity, the scaling is more effective absorbing the pressure gradient effects. However, the effects of roughness are almost removed, while the effects of pressure gradient are still observed on the outer flow, when the mean deficit velocity profiles are normalized by the U∞ δ∗/δ scaling. Furthermore, when scaled with U2∞, the 〈u2〉 component of the Reynolds stress augments due to the rough surface despite the imposed favourable pressure gradient; when using the friction velocity scaling u∗2, it is dampened. It becomes ‘flatter’ in the inner region mainly due to the rough surface, which destroys the coherent structures of the flow and promotes isotropy. Similarly, the pressure gradient imposed on the flow decreases the magnitude of the Reynolds stress profiles especially on the 〈v2〉 and -〈uv〉 components for the u∗2 or U∞2 scaling. These effects are reflected in the boundary layer parameter δ∗/δ, which increase due to roughness, but decrease due to the favourable pressure gradient. Additionally, the pressure parameter Λ found not to be in equilibrium, describes the development of the turbulent boundary layer, with no influence of the roughness linked to this parameter. These measurements are the first with an extensive number of downstream locations (11). This makes it possible to compute the required x-dependence for the production term and the wall shear stress from the full integrated boundary layer equation. The finding indicates that the skin friction coefficient depends on the favourable pressure gradient condition and surface roughness.

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