Vortex Detection Methods 3d Flow

beyonder · August 4, 2013, 09:22

Hi everyone,

i have a 3d wind field, in other words a 3d matrix 300*100*200 (using matlab)
i have been making nice videos with curl/isosurface commands ...
lately it has come to my attention that it is possible to use other vortex detection methods such as;
delta criterion,q criterion , lambda 2, curl (most common) at the moment among these I am using the curl of velocity (vorticity) and the q criterion
but i have no idea how you would implement delta criterion or lambda 2#
i know this is a very specific question
but maybe someone could help ?
thanks in advance
there is also a related article but i dont get it http://jeb.biologists.org/content/211/8/1221.long

SB123 · December 7, 2014, 11:45

i'm looking for the same thing, i'd love to visualize the shed vorticies on my simulation

scott_rumage · December 8, 2014, 11:45

An article titled “Some Computation Required: Vortex Visualization Revisited” by Scott Imlay of Tecplot may be helpful to your work. Here is a link: http://download.tecplot.com/docs/Some_Computation_Required_Vortex_Visualization_Rev isited.pdf

Some of the capabilities you are seeking are now included with Tecplot 360 EX. You can try the demo version of this application at this link: http://www.tecplot.com/my/free-trial-software/

Regards,
Scott R.

jackchilvers · December 18, 2014, 07:33

I recently completed my MSc thesis focusing on vortex propogation downstream of a wingtip in ground effect. To visualise the intensity of the filament I elected to use the normalised axial velocity (u/U_inf) and crossflow velocity (sqrt[v^2 + w^2]/U_inf), both of which worked nicely for me. I hope this helps!

Field85 · January 22, 2015, 13:39

Hi Jack,

Could you tell me if you used a separate post processing software to help with your visualizations?

I am currently finishing a final year project for Mech degree on simulation the wake of a wind turbine to analyze the vortical flows. I have created the sim in STAR CCM+ but it does not seem great for the post processing imagery.

I have tried using AMIRA and Avizo Wind, but input file acceptance is a big issue. Which is a shame as they are both fantastic for post processing.

Any input appreciated

Declan.

August 4, 2013, 09:22	Vortex Detection Methods 3d Flow	#1
beyonder New Member emre Join Date: Mar 2012 Posts: 8 Rep Power: 14	Hi everyone, i have a 3d wind field, in other words a 3d matrix 300100200 (using matlab) i have been making nice videos with curl/isosurface commands ... lately it has come to my attention that it is possible to use other vortex detection methods such as; delta criterion,q criterion , lambda 2, curl (most common) at the moment among these I am using the curl of velocity (vorticity) and the q criterion but i have no idea how you would implement delta criterion or lambda 2# i know this is a very specific question but maybe someone could help ? thanks in advance there is also a related article but i dont get it http://jeb.biologists.org/content/211/8/1221.long shreyasr likes this.

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December 7, 2014, 11:45		#2
SB123 Member Join Date: Mar 2013 Posts: 42 Rep Power: 13	i'm looking for the same thing, i'd love to visualize the shed vorticies on my simulation

December 8, 2014, 11:45		#3
scott_rumage Senior Member Scott Rumage Join Date: May 2009 Location: Seattle, WA Posts: 152 Rep Power: 17	An article titled “Some Computation Required: Vortex Visualization Revisited” by Scott Imlay of Tecplot may be helpful to your work. Here is a link: http://download.tecplot.com/docs/Some_Computation_Required_Vortex_Visualization_Rev isited.pdf Some of the capabilities you are seeking are now included with Tecplot 360 EX. You can try the demo version of this application at this link: http://www.tecplot.com/my/free-trial-software/ Regards, Scott R.

December 18, 2014, 07:33		#4
jackchilvers New Member Jack Chilvers Join Date: Dec 2013 Location: St Neots, Cambridgeshire Posts: 12 Rep Power: 13	I recently completed my MSc thesis focusing on vortex propogation downstream of a wingtip in ground effect. To visualise the intensity of the filament I elected to use the normalised axial velocity (u/U_inf) and crossflow velocity (sqrt[v^2 + w^2]/U_inf), both of which worked nicely for me. I hope this helps!

January 22, 2015, 13:39		#5
Field85 Member Join Date: May 2014 Posts: 31 Rep Power: 12	Hi Jack, Could you tell me if you used a separate post processing software to help with your visualizations? I am currently finishing a final year project for Mech degree on simulation the wake of a wind turbine to analyze the vortical flows. I have created the sim in STAR CCM+ but it does not seem great for the post processing imagery. I have tried using AMIRA and Avizo Wind, but input file acceptance is a big issue. Which is a shame as they are both fantastic for post processing. Any input appreciated Declan.