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

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

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.

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.

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

Performance of Two-Equation Turbulence Models for Flat Plate Flows With Leading Edge Bubbles

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
S. Collie ◽  
M. Gerritsen ◽  
P. Jackson
Keyword(s):  
Flat Plate ◽  
Turbine Blades ◽  
Turbulence Models ◽  
Leading Edge ◽  
Test Case ◽  
Sst Model ◽  
Two Dimensional Flow ◽  
Experimental Values ◽  
University Of Bristol ◽  
Sharp Leading Edge

This paper investigates the performance of the popular k-ω and SST turbulence models for the two-dimensional flow past the flat plate at shallow angles of incidence. Particular interest is paid to the leading edge bubble that forms as the flow separates from the sharp leading edge. This type of leading edge bubble is most commonly found in flows past thin airfoils, such as turbine blades, membrane wings, and yacht sails. Validation is carried out through a comparison to wind tunnel results compiled by Crompton (2001, “The Thin Aerofoil Leading Edge Bubble,” Ph.D. thesis, University of Bristol). This flow problem presents a new and demanding test case for turbulence models. The models were found to capture the leading edge bubble well with the Shear-Stress Transport (SST) model predicting the reattachment length within 7% of the experimental values. Downstream of reattachment both models predicted a slower boundary layer recovery than the experimental results. Overall, despite their simplicity, these two-equation models do a surprisingly good job for this demanding test case.

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