# How to get a plot of fluctuating velocity component{u'(t)} in a turbulent flow

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 November 19, 2012, 02:50 How to get a plot of fluctuating velocity component{u'(t)} in a turbulent flow #1 New Member   Taryk Join Date: Nov 2012 Posts: 9 Rep Power: 4 How can we plot fluctuating component of velocity {u'(t)} in a turbulent flow in a channel with respect to time at a point. Regards TQIM

 November 19, 2012, 11:34 #2 Member   Reza Join Date: Mar 2009 Location: Appleton, WI Posts: 99 Rep Power: 8 You can create a probe under derived parts and monitor the velocity, or define a field function equal to the velocity minus the average velocity, and then monitor that, but you need to have a value for the average velocity, and that means you should have run the simulation for a long enough time that you have a statistically converged value for the mean velocity. Are you using LES, DES, or DNS?

January 25, 2014, 03:52
#3
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Aqua
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Hi, Can I ask a similar question please: I am using LES to perform simulation around a cylinder. To compare the results from LES to a time averaged simulation result (like RANS), I would like to plot a scalar of the mean pressure from the LES transient results.

So, I will need to define a filed function, which means, the time average pressure of each point for a certain time.

Aqua

Quote:
 Originally Posted by triple_r You can create a probe under derived parts and monitor the velocity, or define a field function equal to the velocity minus the average velocity, and then monitor that, but you need to have a value for the average velocity, and that means you should have run the simulation for a long enough time that you have a statistically converged value for the mean velocity. Are you using LES, DES, or DNS?

October 16, 2014, 12:30
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Quote:
 Originally Posted by aqua Hi, Can I ask a similar question please: I am using LES to perform simulation around a cylinder. To compare the results from LES to a time averaged simulation result (like RANS), I would like to plot a scalar of the mean pressure from the LES transient results. So, I will need to define a filed function, which means, the time average pressure of each point for a certain time. How to define that field function? Please help and thank you! Aqua
i agree with aqua, i'd liek to do this too?

 October 18, 2014, 12:10 #5 Member   Chaotic Water Join Date: Jul 2012 Posts: 51 Rep Power: 5 I guess Monitors -> -> Field Mean/Variance Monitor might help - depends on value you are trying to estimate; where Field Function argument of Monitor should be Report in specfifc volume of interest.

November 10, 2014, 11:34
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Rain
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Quote:
 Originally Posted by cwl I guess Monitors -> -> Field Mean/Variance Monitor might help - depends on value you are trying to estimate; where Field Function argument of Monitor should be Report in specfifc volume of interest.

November 10, 2014, 18:51
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Quote:
 Originally Posted by gravis See also Article Number 3668 in the Steve Portal.

AHHH thanks!!!

 November 11, 2014, 11:22 #8 Member   Join Date: Mar 2013 Posts: 42 Rep Power: 4 so this does a field function, or average parameter. how would one go about plotting a average velocity contour map, ie create scalar scene velocity across flow regime along plane C/S. and it varies with each time step... (duh), but then take all of those and create average over entire simulation

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