Harmonic Analysis Results

[bigmigfan]

For the harmonic model that I have, I need the solutions as amplitude and phase. Even though I select amplitued and phase in "Analysis Options". The contour plot displays the real and imaginary solutions. my models consists of a 2D cylinder surrounded with air. The pressure loads are applied at a certain distance from the radius of the cylinder in the fluid domain. I am looking for the pressure distribution at 3KHz of frequency in amplitude and phase.

 

[Drej]

Assume you've tried:

/solu
HROUT,ON

?

How do you know that the results are in real and imaginary?


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[Drej]

Just realised that I may have confused you, but hope you obviously picked up that:

/solu
HROUT,OFF

would give you the required results in amplitude and phase as a solution command. This is the default but remember to re-solve to get these in the current results file.


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[bigmigfan]

hi Drej,
I did try HROUT,OFF but the pressure contour plot still displays real and imaginary solution. Even when you solve the current LS, the status window ensures that the solution will be amplitude and phase, if you have chosen that.

 

[Drej]

There's no reason why it should do that, although if you're using the ANSYS GUI to do the harmonic analysis, there are some known difficulties for this type of analysis using the GUI. The problem is is that you don't always know the exact status/content/etc. of your ANSYS db file. Hence I recommend you use APDL and ANSYS commands within a text file to do this type of analysis, if you're not already. If you are, then post the macro so I can have a closer look.


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[bigmigfan]

Finally, I figured out how to get contour plots in amplitudes for a given phase angle.
In the POST1, there is a command (HRCPLX) which lets you see the pressure distribution in amplitude for a specified phase angle (phase angle=>360, see the help under this command in ANSYS guide).

Drej as you suggested, the command HROUT,OFF only lists the output in .out files not in .rst.

 

[bigmigfan]

Well we can also list the solution in Time-History Processor to obtain the amplitude and phase via PRCPLX command.

Just for the sake of knowledge, is it possible to view the solutions for all the nodes rather than just the particular node in Time-History Processor? How can we expand the results (i.e. obtained amplitude and phase) back into POST1 ?

 

[Drej]

> is it possible to view the solutions for all the nodes rather than just the particular node in Time-History Processor?

/post26 allows you to PLOT the behaviour of 1 node over a spectrum of frequencies, while /post1 allows you to VIEW the behaviour (contours of UX, SEQV, etc.) at one particular frequency.

> How can we expand the results (i.e. obtained amplitude and phase) back into POST1 ?


It's the other way round. I assume that because you're expanding the results you're carrying out a mode-superposition (for example) extraction. In this case you expand the results to the jobname.RFRQ and use this results file in /post26. The jobname.RST is used in /post1.


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