RAREFIED VISCOUS FLOW NEAR A SHARP LEADING EDGE

AIAA Journal ◽  
1963 ◽  
Vol 1 (4) ◽  
pp. 956-958 ◽  
Author(s):  
EDGAR BENDOR
Keyword(s):  
Viscous Flow ◽  
Leading Edge ◽  
Sharp Leading Edge

Hypersonic viscous flow near a sharp leading edge

AIAA Journal ◽  
1964 ◽  
Vol 2 (9) ◽  
pp. 1660-1661 ◽  
Author(s):  
RICHARD W. GARVINE
Keyword(s):  
Viscous Flow ◽  
Leading Edge ◽  
Sharp Leading Edge

Numerical Computation of Hypersonic Viscous Flow over a Sharp Leading Edge

AIAA Journal ◽  
1974 ◽  
Vol 12 (2) ◽  
pp. 129-130 ◽  
Author(s):  
J. C. TANNEHILL ◽  
R. A. MOHLING ◽  
J. V. RAKICH
Keyword(s):  
Viscous Flow ◽  
Numerical Computation ◽  
Leading Edge ◽  
Sharp Leading Edge

Application Of Elastic Layers To Register Pressure Field On The Model Surface In Supersonic Flow

2016 ◽  
Vol 11 (1) ◽  
pp. 23-33
Author(s):  
Maxim Golubev ◽  
Andrey Shmakov
Keyword(s):  
Surface Waves ◽  
High Frequency ◽  
High Speed ◽  
Pressure Pulsation ◽  
Pressure Field ◽  
Leading Edge ◽  
Supersonic Wind Tunnel ◽  
Register Pressure ◽  
Elastic Layers ◽  
Sharp Leading Edge

The work presents the results of application of panoramic interferential technique which is based on elastic layers (sensors) usage to obtain pressure distribution on the flat plate having sharp leading edge. Experiments were done in supersonic wind tunnel at Mach number M = 4. Sensitivity and response time are shown to be enough to register pressure pulsation against standing and traveling sensor surface waves. Applying high-frequency image acquiring is demonstrated to make possible to distinguish at visualization images high-speed disturbances propagating in the boundary layer from low-speed surface waves

scholarly journals Numerical Simulation of 3D Viscous Flow in a Linear Compressor Cascade With Tip Clearance

1994 ◽  
Author(s):  
Shun Kang ◽  
Charles Hirsch
Keyword(s):  
Viscous Flow ◽  
Flow Structure ◽  
Leading Edge ◽  
Secondary Flows ◽  
Tip Clearance ◽  
Flow Coefficient ◽  
Compressor Cascade ◽  
Tip Leakage Flow ◽  
Linear Compressor ◽  
Linear Compressor Cascade

A Navier-Stokes solver is applied to investigate the 3D viscous flow in a low speed linear compressor cascade with tip clearance at design and off-design conditions with two different meshes. The algebraic turbulence model of Baldwin-Lomax is used for closure. Relative motion between the blades and wall is simulated for one flow coefficient. Comparisons with experimental data, including flow structure, static and total pressures, velocity profiles, secondary flows and vorticity, are presented for the stationary wall case. It is shown that the code predicts well the flow structure observed in experiments and shows the details of the tip leakage flow and the leading edge horseshoe vortex.

Flow in the initial segment of a tube with a sharp leading edge

1989 ◽  
Vol 56 (2) ◽  
pp. 140-143 ◽  
Author(s):  
V. M. Legkii ◽  
V. A. Rogachev
Keyword(s):  
Initial Segment ◽  
Leading Edge ◽  
Sharp Leading Edge

Investigation of the separation bubble formed behind the sharp leading edge of a flat plate at incidence

2000 ◽  
Vol 214 (3) ◽  
pp. 157-176 ◽  
Author(s):  
M J Crompton ◽  
R V Barrett
Keyword(s):  
Reynolds Number ◽  
Flat Plate ◽  
Laser Doppler Anemometry ◽  
Reverse Flow ◽  
Separation Bubble ◽  
Flow Direction ◽  
Leading Edge ◽  
Laser Doppler ◽  
Static Pressure Distribution ◽  
Sharp Leading Edge

Detailed measurements of the separation bubble formed behind the sharp leading edge of a flat plate at low speeds and incidence are reported. The Reynolds number based on chord length ranged from 0.1 × 105 to 5.5 × 105. Extensive use of laser Doppler anemometry allowed detailed velocity measurements throughout the bubble. The particular advantages of laser Doppler anemometry in this application were its ability to define flow direction without ambiguity and its non-intrusiveness. It allowed the mean reattachment point to be accurately determined. The static pressure distribution along the plate was also measured. The length of the separation bubble was primarily determined by the plate incidence, although small variations occurred with Reynolds number because of its influence on the rate of entrainment and growth of the shear layer. Above about 105, the Reynolds number effect was no longer evident. The reverse flow boundary layer in the bubble exhibited signs of periodic stabilization before separating close to the leading edge, forming a small secondary bubble rotating in the opposite sense to the main bubble.

Actively flapping tandem flexible flags in a viscous flow

2015 ◽  
Vol 780 ◽  
pp. 120-142 ◽  
Author(s):  
Emad Uddin ◽  
Wei-Xi Huang ◽  
Hyung Jin Sung
Keyword(s):  
Viscous Flow ◽  
Immersed Boundary Method ◽  
Leading Edge ◽  
Underlying Mechanism ◽  
The Body ◽  
Immersed Boundary ◽  
Flexible Body ◽  
Flexible Bodies ◽  
Body Shapes ◽  
Heave Motion

The active flapping motions of fish and cetaceans generate both propulsive and manoeuvring forces. The tail fin motions of the majority of fish can essentially be viewed as a combined pitch-and-heave motion. Downstream bodies are strongly influenced by the vortices shed from an upstream body. To investigate the interactions between flexible bodies and vortices, the present study examined tandem flexible flags in a viscous flow by using an improved version of the immersed boundary method. The upstream flag underwent passive flapping in a uniform flow while the downstream flag flapped according to a prescribed pitching and heaving motion of the leading edge. The influences of the active flapping motion on the system dynamics were examined in detail, including the frequency, the phase angle, the bending coefficient and the amplitudes of the pitching and heaving motion. The variation of the drag coefficient of the downstream flag was explored together with the instantaneous vorticity contours and the body shapes. Both the slalom mode and the interception mode were identified according to the vortex–flexible body interactions, corresponding to the low- and high-drag situations, respectively. The underlying mechanism was discussed and compared with previous studies.

Optimized Performance of Condensers with Outside Condensing Surfaces

1981 ◽  
Vol 103 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Y. Mori ◽  
K. Hijikata ◽  
S. Hirasawa ◽  
W. Nakayama
Keyword(s):  
Leading Edge ◽  
Vertical Tube ◽  
Controlling Factors ◽  
Numerical Calculations ◽  
Surface Geometry ◽  
Guiding Principle ◽  
Wide Groove ◽  
Analytical Result ◽  
Sharp Leading Edge ◽  
Fin Shape

The purpose of this paper is to find an optimum surface geometry of vertical condenser tubes where condensation takes place on the outer surfaces. The guiding principle on optimum condensation performance is to make the thickness of condensate liquid on the surfaces as thin as possible. A vertical tube with longitudinally parallel tiny fins is preferable because condensate is made thinner over the widest possible region. According to an analysis, there are four controlling factors for the optimum fin; sharp leading edge, gradually changing curvature of fin surface from tip to the root, wide groove between fins to collect condensate and horizontal discs attached to the tube to remove condensate. The analytical result is checked by experiments using R-113. The optimum fin shape, fin pitch and spacing of discs are found by numerical calculations for R-113 and water.

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