[TQIM]

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

[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?

[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

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?

[SB123]

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?

[cwl]

I guess Monitors -> <Right-Click> -> 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.

[gravis]

Originally Posted by cwl

I guess Monitors -> <Right-Click> -> 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.

See also Article Number 3668 in the Steve Portal.

[SB123]

Originally Posted by gravis

See also Article Number 3668 in the Steve Portal.

AHHH thanks!!!

[SB123]

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