Direct Numerical Simulation of Receptivity to Roughness in a Swept-Wing Boundary Layer at High Reynolds Numbers

An experimental and analytical study has been performed on the effect of Reynolds number and free-stream turbulence on boundary layer transition location on the suction surface of a controlled diffusion airfoil (CDA). The experiments were conducted in a rectilinear cascade facility at Reynolds numbers between 0.7 and 3.0×106 and turbulence intensities from about 0.7 to 4%. An oil streak technique and liquid crystal coatings were used to visualize the boundary layer state. For small turbulence levels and all Reynolds numbers tested the accelerated front portion of the blade is laminar and transition occurs within a laminar separation bubble shortly after the maximum velocity near 35–40% of chord. For high turbulence levels (Tu > 3%) and high Reynolds numbers transition propagates upstream into the accelerated front portion of the CDA blade. For those conditions, the sensitivity to surface roughness increases considerably and at Tu = 4% bypass transition is observed near 7–10% of chord. Experimental results are compared to theoretical predictions using the transition model which is implemented in the MISES code of Youngren and Drela. Overall the results indicate that early bypass transition at high turbulence levels must alter the profile velocity distribution for compressor blades that are designed and optimized for high Reynolds numbers.

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Local isotropy of the velocity and vorticity fields in a boundary layer at high Reynolds numbers

Physics of Fluids ◽

10.1063/1.3005842 ◽

2008 ◽

Vol 20 (10) ◽

pp. 101506 ◽

Cited By ~ 2

Author(s):

James M. Wallace ◽

Lawrence Ong

Keyword(s):

Boundary Layer ◽

Reynolds Numbers ◽

Local Isotropy ◽

High Reynolds Numbers ◽

High Reynolds

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Numerical Simulation Around Airfoil with High Resolution in High Reynolds Numbers

45th AIAA Aerospace Sciences Meeting and Exhibit ◽

10.2514/6.2007-720 ◽

2007 ◽

Cited By ~ 1

Author(s):

Takuji Kurotaki ◽

Takahiro Sumi ◽

Takashi Atobe ◽

Jun Hiyama

Keyword(s):

Numerical Simulation ◽

High Resolution ◽

Reynolds Numbers ◽

High Reynolds Numbers ◽

High Reynolds

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Temperature Control of Blow-Down, Supersonic Tunnels

Journal of the Royal Aeronautical Society ◽

10.1017/s0368393100132444 ◽

1956 ◽

Vol 60 (541) ◽

pp. 67-70

Author(s):

T. A. Thomson

Keyword(s):

Heat Transfer ◽

Boundary Layer ◽

Reynolds Number ◽

Mach Number ◽

Reynolds Numbers ◽

Stagnation Temperature ◽

Blow Down ◽

High Reynolds Numbers ◽

Experimental Errors ◽

High Reynolds

The blow-down type of intermittent, supersonic tunnel is attractive because of its simplicity and because relatively high Reynolds numbers can be obtained for a given size of test section. An adverse characteristic, however, is the fall of stagnation temperature during runs, which can affect experiments in several ways. The Reynolds number varies and the absolute velocity is not constant, even if the Mach number and pressure are; heat-transfer cannot be studied under controlled conditions and the experimental errors arising from the effect of heat-transfer on the boundary layer vary in time. These effects can become significant in quantitative experiments if the tunnel is large and the variation of temperature very rapid; the expense required to eliminate them might then be justified.

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Experiments on the Flow Around a Sphere at High Reynolds Numbers

Journal of Applied Mechanics ◽

10.1115/1.3564723 ◽

1969 ◽

Vol 36 (3) ◽

pp. 598-607 ◽

Cited By ~ 42

Author(s):

T. Maxworthy

Keyword(s):

Boundary Layer ◽

Turbulent Boundary Layer ◽

Pressure Distribution ◽

Reynolds Numbers ◽

Boundary Layer Separation ◽

Recirculation Region ◽

Layer Separation ◽

High Reynolds Numbers ◽

High Reynolds

Flow around a sphere for Reynolds numbers between 2 × 105 and 6 × 104 has been observed by measuring the pressure distribution around a circle of longitude under a variety of conditions. These include the effects of laminar and turbulent boundary layer separation, tunnel blockage, various boundary layer trip arrangements and inserting an object to disrupt the unsteady, recirculation region behind the sphere.

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