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Harris

CGWAVE: output time series / spectrum

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Hi all,

Does anyone know whether CGWAVE can output the wave spectrum at a an output point?

or, alternatively,

is it possible to modify the time step and length of the output time series?

I want to use a white noise spectrum as input, say in the band from 20Hz to 200Hz, in order to determine the resonance frequencies of a harbour.

If the first component of input spectrum is the T=20sec component, the time interval of the output time series is 1sec and the duration 20sec.

If the longest duration component (T=200sec) is first, the time interval is 10sec and the duration 200sec.

It appears that the time series outplot plot corresponds to the first component of the input spectrum.

Fot this example, to be effective, the output time series should be at least 200sec long and the time interval 1/400sec.

In both cases the provided time series is not sufficient to determine the wave spectrum at an output point.

Thanks,

Harris

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Hello,

I would also like to know whether CGWAVE can output the wave spectrum at a an output point?

Does anyone know this?

It seems from an old version of the CGWAVE manual that this used to possible. It would be a very useful feature...

Thanks and best regards,

Juliane

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CGWAVE is not a transient model. The output that it generates includes phase resolving information so the wave can be displayed as it moves across the domain, but there is no "time step".

SMS breaks the wave down into 20 snapshots through the wave period by defualt. You can use the "trans" program to read the solution file and sample at a different frequency.

Each wave component is considered independently by CGWAVE, so the "cgo" file includes output at each node for each wave component. When SMS reads this by default it composes the wave into a single visualization term. However, you can split the output file into separate files for each component to view individually. We are considering an option in SMS to allow you to read the solution as a single composed wave, or a series of solution for each input. Let me know if that would be a priority for you.

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Hello, how does one obtain the "trans" program?

We are still very interested in obtaining the wave spectrum in a certain point...

Best regards

Juliane

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