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-   -   WAVES with VOF (http://www.cfd-online.com/Forums/fluent/28081-waves-vof.html)

Panayotis Prinos December 7, 2000 07:13

WAVES with VOF
 
Dear Colleagues We try to solve the problem of wave propagation on constant water depth using the VOF method of FLUENT 5.4 but we have not succeeded yet. We give as inlet conditions the U and V velocities as a function of time and a kind of wave is constructed near the inlet which "dies" out further downstream in contrast with the exact solution which gives unaltered waves of certain wave length in the whole domain.

I have the following questions (a) Can anyone verify that this kind of problems (propagation of upstream disturbances) can be solved with such a code ? (b) Has anyone worked with this or similar type of problem ? (c) Are there any publications with the application of FLUENT to these kind of problems.

Thank you for your response

mike December 17, 2000 18:58

Re: WAVES with VOF
 
I have been developing a similar model to investigate efficiencies of shore based wave energy devices using Fluent with the VOF model. I have been getting quite good results using a similar technique -ie using a UDF to define inlet U & V velocities. I have been using parameters with 0.5m-1m amplitude waves in 6-8m water depth. I define the height of the velocity inlet to be greater than (water depth + wave amplitude) & set the velocities above the varying water surface to be zero within the UDF. The domains I am using are only 2 or 3 wavelengths though

This has worked quite well for stokes 2nd order wave theories but it took a while to determine mesh sizing (as small as practical near surface)., modelling technique (ie geometric reconstruction)etc.. to get the modelling working.

It also takes a while for a wave of correct height to develop at the inlet starting from a flat surface due to conservation of energy

please specify any specific problems - i may be able to assist


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