Large scale structures of high Reynolds number turbulent boundary layers

22 mins 55 secs, 79.63 MB, Windows Media Video 44100 Hz, 474.41 kbits/sec

Share this media item:

Embed this media item:

<iframe width="_width_" height="_height_" src="https://sms.cam.ac.uk/media/18147/embed" frameborder="0" scrolling="no" allowfullscreen></iframe>

Choose size:

About this item

Available Formats

About this item

Large scale structures of high Reynolds number turbulent boundary layers's image

Description:	Tutkun, M (Norwegian Defense Research Establishment) Thursday 11 September 2008, 14:20-14:40

Created:

2008-10-08 14:46

Collection:

The Nature of High Reynolds Number Turbulence

Publisher:

Isaac Newton Institute

Tutkun, M

Language:

eng (English)

Keywords:

Transition; Turbulence;

Credits:

Author:	Tutkun, M
Producer:	Steve Greenham


Abstract:	Time-resolved measurements from the European Wallturb consortium experiment conducted using the large Laboratoire de Mecanique de Lille (LML) wind tunnel at Lille, France are reported. Data were taken at Re_theta = 9,800 and 19,100. Data were obtained using a rake of 143 single hot-wires which were spaced logarithmically across the flow in the spanwise and vertical directions over a distance approximately equal to the boundary layer thickness of 0.3 m. The wires were calibrated in situ using data from the simultaneous PIV experiment in a plane just upstream of the wire. Other PIV planes were also recorded in synch with the hot-wire data acquisition. This paper reports the cross-correlations and spectra generated among the wires themselves and those generated the upstream PIV plane immediately upstream of the rake. The existence of very long elongated structures are also shown by the space-time correlations obtained using the hot-wire rake data. Proper orthogonal decomposition (POD) applied on the same how-wire rake data are found to be very efficient in term of energy such that only a few spanwise wavenumber modes are necessary to capture 90% of the energy, and the details POD results like eigenspectra and eigenfunctions are discussed in the paper. A seminar from the Wall Bounded Shear Flows: Transition and Turbulence conference in association with the Newton Institute programme: The Nature of High Reynolds Number Turbulence www.newton.ac.uk/programmes/HRT/seminars/

Abstract:

Time-resolved measurements from the European Wallturb consortium experiment conducted using the large Laboratoire de Mecanique de Lille (LML) wind tunnel at Lille, France are reported. Data were taken at Re_theta = 9,800 and 19,100. Data were obtained using a rake of 143 single hot-wires which were spaced logarithmically across the flow in the spanwise and vertical directions over a distance approximately equal to the boundary layer thickness of 0.3 m. The wires were calibrated in situ using data from the simultaneous PIV experiment in a plane just upstream of the wire. Other PIV planes were also recorded in synch with the hot-wire data acquisition. This paper reports the cross-correlations and spectra generated among the wires themselves and those generated the upstream PIV plane immediately upstream of the rake. The existence of very long elongated structures are also shown by the space-time correlations obtained using the hot-wire rake data. Proper orthogonal decomposition (POD) applied on the same how-wire rake data are found to be very efficient in term of energy such that only a few spanwise wavenumber modes are necessary to capture 90% of the energy, and the details POD results like eigenspectra and eigenfunctions are discussed in the paper.

A seminar from the Wall Bounded Shear Flows: Transition and Turbulence conference in association with the Newton Institute programme: The Nature of High Reynolds Number Turbulence www.newton.ac.uk/programmes/HRT/seminars/

Available Formats

Format	Quality	Bitrate	Size
MPEG-4 Video	480x360	1.83 Mbits/sec	313.61 MB	View	Download
WebM	450x360	686.81 kbits/sec	114.02 MB	View	Download
Flash Video	480x360	801.58 kbits/sec	134.54 MB	View	Download
iPod Video	480x360	502.16 kbits/sec	84.29 MB	View	Download
QuickTime	384x288	842.04 kbits/sec	141.33 MB	View	Download
MP3	44100 Hz	125.02 kbits/sec	20.62 MB	Listen	Download
Windows Media Video *		474.41 kbits/sec	79.63 MB	View	Download
Auto	(Allows browser to choose a format it supports)