CFD Online Logo CFD Online URL
Home > Forums > General Forums > Main CFD Forum

Strouhal No

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   September 19, 2002, 10:58
Default Strouhal No
Posts: n/a
I need to know where should be the location of probe for calculating the vortex shedding frequency and what parameter should be considered for calculating the time-period of vortex shedding
  Reply With Quote

Old   September 19, 2002, 11:55
Default Re: Strouhal No
Posts: n/a
1. Depends on your probe, the locations should be different. For Hot-wire, it should be located in the low turbulence region.

2. About 30 times (of the body size) downstream, you can get shedding frequency from the measured data.

3. Estimate the approximate shedding frequency of you model and decide the sampling frequency.
  Reply With Quote

Old   September 20, 2002, 03:22
Default Re: Strouhal No
Jan Rusås
Posts: n/a
If LDA is used for the measuring is there requirement to where it should be measured. I need to find the shedding frequency in a tube bank, and I want to measure between the tubes. The distance between the tubes is 1 diameter. Jan
  Reply With Quote

Old   September 20, 2002, 10:14
Default Re: Strouhal No
Posts: n/a
1. LDA is prohibitive to measure velocity very close to the cylinder.

2. Depends on the Reynolds number, the flow could be three dimensional. Since the distance bet. cylinders are 1-D, the wake might be almost two dimensional. That means you don't need to measure the properties of streamwise coherent structures.

3. Due to the interference, it might be possible that the shedding frequency changes depending on the measuring positions.

4. At some positions, double or tripple frequency is dominant in the power spectral density function.

  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Strouhal Numbers and Meshes soggy316 FLUENT 0 February 17, 2010 06:15
Strouhal Number alansari FLUENT 2 February 8, 2010 15:36
Questions regarding strouhal number Ben Main CFD Forum 7 January 15, 2007 20:32
Turbulent Cylinder Strouhal Number Chetan Kadakia FLUENT 3 October 10, 2002 03:31
Strouhal number J. Held Main CFD Forum 0 March 26, 1999 05:10

All times are GMT -4. The time now is 23:44.