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Coupled Monopole domain source in pressure acoustics.

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Hi there,

I am using acoustics module in COMSOL 5.3a to simulate some thermoacoustic instabilities. So, to solve this problem, I'm using pressure acoustics Physics based on the inhomogeneous helmholtz equation.

A simple n-tau model was applied to Monopole domain source to combine the perturbation of velocity in the upstream of the heat release zone with the perturbation in pressure in the heat release zone.

As a result, we analyze Eigenfrequency, which is a form of complex numbers. In thermoacoustics analysis, the imaginary part of eigenfrequency is greatly affected by changes in the Monopole domain source. In my field, Real part of Eigenfrequency mean frequency, and the Imaginary part mean growth rate.

However, The analysis results by applying the Monopole domain source showed a large error compared to the resonant frequency obtained from the acoustic analysis (if there is no heat emission). We also found that there was no significant impact on the imaginary part (over 300 Hz, the imaginary part was close to zero).

I think it's a problem that applies to the Monopole domain source.

I tried to solve this problem in many ways, but I couldn't find the answer. To help you understand what problems I am facing, I have summarized the process of my study like an attached example.

If anyone knows the problem, Any advice and comment on my questions will be really helpful for my study.

Thank you.

Sumin Hong

0 Replies Last Post 2020年3月6日 GMT+8 下午4:30
COMSOL Moderator

Hello Sumin Hong

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