LDV measurements of turbulent baroclinic boundary layers

Conference · Thu Jul 01 04:00:00 EDT 1993

OSTI ID:10192039

Neuwald, P; Reichenbach, H ^[1]; Kuhl, A L ^[2]

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1. Fraunhofer-Institut fuer Kurzzeitdynamik - Ernst-Mach-Institut (EMI), Freiburg im Breisgau (Germany)
2. Lawrence Livermore National Lab., El Segundo, CA (United States)

Described here are shock tube experiments of nonsteady, turbulent boundary layers with large density variations. A dense-gas layer was created by injecting Freon through the porous floor of the shock tube. As the shock front propagated along the layer, vorticity was created at the air-Freon interface by an inviscid, baroclinic mechanism. Shadow-schlieren photography was used to visualize the turbulent mixing in this baroclinic boundary layer. Laser-Doppler-Velocimetry (LDV) was used to measure the streamwise velocity histories at 14 heights. After transition, the boundary layer profiles may be approximated by a power-law function u {approximately} u{sup {alpha}} where {alpha} {approx_equal} 3/8. This value lies between the clean flat plate value ({alpha} = 1/7) and the dusty boundary layer value ({alpha} {approx_equal} 0.7), and is controlled by the gas density near the wall.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); Defense Nuclear Agency, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10192039
• Report Number(s): UCRL-JC--113306; CONF-930788--7; ON: DE94002025; CNN: Grant DNA IACRO 92-824; Grant DNA 001-91-C-0039
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450100
BOUNDARY LAYERS
CHEMICAL EXPLOSIONS AND EXPLOSIVES
DETONATIONS
HEAT TRANSFER AND FLUID FLOW
MIXING
SHOCK TUBES
SHOCK WAVES
TURBULENT FLOW
VELOCIMETERS
WAVE PROPAGATION