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Prescribe boundary at a location where you expect 2-layer flow?
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Prescribe boundary at a location where you expect 2-layer flow? 11 years 7 months ago #8140

  • ewang
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I have set up a model where I prescribed water levels at 1) entrance of the strait and 2) middle of the strait. The project site is between the two boundaries. Two layer flow is known to occur due to the bathymetry. The model generated quite a bit of re-circulation at the 2nd boundary (middle of the strait). I have tried various turbulence models, parameters and nothing helped to improve the result. I am suspecting that neither the classic or Thompson's method is able to deal with the condition where you have two-layer flow and that I will need to model the whole strait instead. Does anyone have the similar experience? Thanks.

Edwin
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Prescribe boundary at a location where you expect 2-layer flow? 11 years 7 months ago #8175

  • pham
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Hello Edwin,

Is the extent of your domain big or not? What are the dimensions?
Did you finally try to model the whole strait and if yes, do you still have the same results?
If you only have 2 liquid boundaries (and the others that are solid) and prescribe only the elevations, the problem may be not well posed. You should try to prescribe a velocity information on one liquid boundary (or at least one part).

Regards,

Chi-Tuan
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Prescribe boundary at a location where you expect 2-layer flow? 11 years 7 months ago #8199

  • ewang
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Hi,

What I found was that when I prescribed 'observed' water level data on the north and south ends of the model, I obtained poor current circulation patterns. When I prescribed 'predicted' water level data based on tidal constituents, the results are much better.

I have also tried extending the mesh to cover the entire strait and I did get better pattern results using either observed or predicted water levels.

Does anyone know if "spherical coordinates" is implemented in TELEMAC3D? The key word "spherical coordinates" is not recognized. My model is over 175 km long. I am wondering if that has impact on the results.

Also, is FOURIER ANALYSIS available for TELEMAC3D or is it only in TELEMAC2D for now? Thanks.

Edwin
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Prescribe boundary at a location where you expect 2-layer flow? 11 years 7 months ago #8202

  • jmhervouet
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Hello,

Spherical coordinates will be taken into account in the next version of Telemac-3D (it is doubtful it has an effect in your domain). Fourier analysis is not available in 3D, you are the first one to ask, I note that in my (long) todo list.

Regards,

JMH
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