Direct measurement of skin friction on a porous flat plate with massinjection

1967 ◽  
Author(s):  
H. DERSHIN ◽  
W. GALLAHER ◽  
C. LEONARD
Keyword(s):  
Flat Plate ◽  
Skin Friction ◽  
Direct Measurement ◽  
Porous Flat Plate

Direct measurement of skin friction on a porous flat plate with massinjection.

AIAA Journal ◽  
1967 ◽  
Vol 5 (11) ◽  
pp. 1934-1939 ◽  
Author(s):  
HARVEY DERSHIN ◽  
CHARLES A. LEONARD ◽  
WILLIAM H. GALLAHER
Keyword(s):  
Flat Plate ◽  
Skin Friction ◽  
Direct Measurement ◽  
Porous Flat Plate

Turbulent Boundary Layers With Unsteady Injection-Suction

1980 ◽  
Vol 102 (3) ◽  
pp. 364-371 ◽  
Author(s):  
D. T. Tsahalis
Keyword(s):  
Flat Plate ◽  
Skin Friction ◽  
Eddy Viscosity ◽  
Steady Flows ◽  
Outer Flow ◽  
Boundary Layer Equations ◽  
Eddy Viscosity Model ◽  
Viscosity Models ◽  
Porous Flat Plate ◽  
Theoretical Results

The time dependent turbulent boundary-layer equations with a two-layer eddy viscosity model are integrated numerically over a porous flat plate for a steady outer flow and a sinusoidally distributed injection-suction that varies harmonically with time. The dependence of the unsteady wall shear on the frequency and strength of injection-suction is investigated. The present results indicate that the time-averaged skin friction is always larger than the skin friction observed over a nonporous flat plate. Comparison with previous theoretical results indicates that the time-averaged skin friction is always smaller than the skin friction observed over a porous flat plate with steady, simultaneous injection-suction of the same strength. The extension of eddy viscosity models, developed for steady flows, to unsteady flows is discussed.

Orthogonal Flow Impinging on a Wall with Suction or Blowing

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Najeeb Alam Khan ◽  
Asmat Ara ◽  
Syed Anwer Ali ◽  
Muhammad Jamil
Keyword(s):  
Incompressible Fluid ◽  
Perturbation Method ◽  
Flat Plate ◽  
Skin Friction ◽  
Homotopy Perturbation Method ◽  
Numerical Solutions ◽  
Viscous Incompressible Fluid ◽  
Approximate Solutions ◽  
Homotopy Perturbation ◽  
Porous Flat Plate

The goal of this work is the approximate solutions of a viscous incompressible fluid impinging orthogonally on a porous flat plate. The equation governing the flow of an incompressible fluid is investigated using the homotopy perturbation method (HPM) with the aid of Padé-approximants. The approximate solutions can be successfully applied to provide the value of the skin-friction. The reliability and efficiency of the approximate solutions were verified using numerical solutions in the literature.

Direct total skin-friction measurement of a flat plate in zero-pressure-gradient boundary layers

2009 ◽  
Vol 41 (2) ◽  
pp. 021406 ◽  
Author(s):  
Kiyoto Mori ◽  
Hiroki Imanishi ◽  
Yoshiyuki Tsuji ◽  
Tomohiro Hattori ◽  
Masaharu Matsubara ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Flat Plate ◽  
Skin Friction ◽  
Boundary Layers ◽  
Friction Measurement

Skin friction and surface temperature of an insulated flat plate fixed in a fluctuating stream

1971 ◽  
Vol 46 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Hiroshi Ishigaki
Keyword(s):  
Boundary Layer ◽  
Surface Temperature ◽  
Flat Plate ◽  
Skin Friction ◽  
High Frequency ◽  
Energy Equation ◽  
Oscillation Amplitude ◽  
Flow Oscillation ◽  
Velocity Amplitude ◽  
The Mean

The time-mean skin friction of the laminar boundary layer on a flat plate which is fixed at zero incidence in a fluctuating stream is investigated analytically. Flow oscillation amplitude outside the boundary layer is assumed constant along the surface. First, the small velocity-amplitude case is treated, and approximate formulae are obtained in the extreme cases when the frequency is low and high. Next, the finite velocity-amplitude case is treated under the condition of high frequency, and it is found that the formula obtained for the small-amplitude and high-frequency case is also valid. These results show that the increase of the mean skin friction reduces with frequency and is ultimately inversely proportional to the square of frequency.The corresponding energy equation is also studied simultaneously under the condition of zero heat transfer between the fluid and the surface. It is confirmed that the time-mean surface temperature increases with frequency and tends to be proportional to the square root of frequency. Moreover, it is shown that the timemean recovery factor can be several times as large as that without flow oscillation.

Application of Air Microblowing Through a Porous Wall for Skin Friction Reduction on a Flat Plate

2010 ◽  
Vol 5 (3) ◽  
pp. 38-46
Author(s):  
Vladimir I. Kornilov ◽  
Andrey V. Boiko
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Skin Friction ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Porous Wall ◽  
Friction Reduction ◽  
Local Skin ◽  
Skin Friction Reduction

The effect of air microblowing through a porous wall on the properties of a turbulent boundary layer formed on a flat plate in an incompressible flow is studied experimentally. The Reynolds number based on the momentum thickness of the boundary layer in front of the porous insert is 3 900. The mass flow rate of the blowing air per unit area was varied within Q = 0−0.0488 кg/s/m2 . A consistent decrease in local skin friction, reaching up to 45−47 %, is observed to occur at the maximal blowing air mass flow rate studied.

A high performance porous flat-plate solar collector

Energy ◽  
1979 ◽  
Vol 4 (4) ◽  
pp. 685-694 ◽  
Author(s):  
F.L. Lansing ◽  
V. Clarke ◽  
R. Reynolds
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
High Performance ◽  
Porous Flat Plate ◽  
Flat Plate Solar Collector
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