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Absolute Value of Temperature at Discrete Time Periods
Posted 22 feb 2016, 20:40 GMT-5 Materials Version 5.0 4 Replies
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I am performing an eigenfrequency analysis and I want to find the absolute value of temperature (T) at each given phase of the oscillation. When I use the expression abs(T) COMSOL creates a profile that is constant at each phase of the oscillation. It seems that abs(T) is the time integral of the absolute value of T(t). Is this correct?
How do I get abs at each discrete time (i.e. abs(T(t)) )?
How do I get abs at each discrete time (i.e. abs(T(t)) )?
4 Replies Last Post 26 feb 2016, 14:54 GMT-5
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Posted:
8 years ago
Hi,
I think you have to give a hint about which type of physical problem you are solving, since in most cases temperature as such is not part of the eigenfrequency problem. Is it thermoacoustics?
Chances that someone will answer your question are also much better if you upload a small example showing what you are trying to do.
Regards,
Henrik
I think you have to give a hint about which type of physical problem you are solving, since in most cases temperature as such is not part of the eigenfrequency problem. Is it thermoacoustics?
Chances that someone will answer your question are also much better if you upload a small example showing what you are trying to do.
Regards,
Henrik
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Posted:
8 years ago
Henrick,
I take the gradient of T in the Z direction using the command TZ. I want to be able to get the absolute value of this at each phase of oscillation but when I use the command abs(TZ) it seems to give me the integral of |TZ(t)| over one period of oscillation. Compare 'Player 2' vs 'Player 3'. The values in 'Player 3' are constant during oscillation but I want the absolute value of the values from 'Player 2' at each phase.
How can I get TZ(t) at each time t?
I attached two images and the .mph model.
Thanks in advance.
I take the gradient of T in the Z direction using the command TZ. I want to be able to get the absolute value of this at each phase of oscillation but when I use the command abs(TZ) it seems to give me the integral of |TZ(t)| over one period of oscillation. Compare 'Player 2' vs 'Player 3'. The values in 'Player 3' are constant during oscillation but I want the absolute value of the values from 'Player 2' at each phase.
How can I get TZ(t) at each time t?
I attached two images and the .mph model.
Thanks in advance.
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Posted:
8 years ago
Hi,
TZ is complex valued. What you see when you plot TZ is actually real(TZ) which is the actual value at the current phase angle in the cycle. When you create abs(TZ) you get the amplitude of the complex value, which is independent of the phase angle.
What I think you want to plot is abs(real(TZ)). This will give you the absolute value of the results at each phase angle.
Not that for the ordinary slice plot, you can enter the phase angle at which you examine the results in the settings for the data set.
Regards,
Henrik
TZ is complex valued. What you see when you plot TZ is actually real(TZ) which is the actual value at the current phase angle in the cycle. When you create abs(TZ) you get the amplitude of the complex value, which is independent of the phase angle.
What I think you want to plot is abs(real(TZ)). This will give you the absolute value of the results at each phase angle.
Not that for the ordinary slice plot, you can enter the phase angle at which you examine the results in the settings for the data set.
Regards,
Henrik
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Posted:
8 years ago
Very helpful.
Now I'm trying to integrate (at each point) the value of abs(real(TZ)) over one oscillation of resonator. I have tried timeavg, timeint and these give me errors. How do I get the sum/integral of the expression abs(real(TZ)) over the desired timespan?
Now I'm trying to integrate (at each point) the value of abs(real(TZ)) over one oscillation of resonator. I have tried timeavg, timeint and these give me errors. How do I get the sum/integral of the expression abs(real(TZ)) over the desired timespan?