Shallow Water Effect on MOSES

Hi Yuni Ari,

Thank you for your question.

There are several ways to include the shallow water effects.  The first and necessary step is to set the water depth with "&env ename -depth".  You can set the default for the analysis with the command "&parameter -depth".  You also have to compute the hydrodynamic database with 3d diffraction.

The above is normally sufficient.

If you are interested in wave interaction you should model an obstacle.

If you have a sloped bottom you should model an obstacle. 

I do not know how much MOSES experience you have.  Maybe the above instructions are sufficient.  Let me know if you have further questions.

Georgina Maldonado

Thanks Georgina,

I am interested in floating structure interactions, such as pipelaying installation using stinger in shallow water. The real condition usually faced  by engineer is the structures moved along with the waves in vertical direction downwards, which increased downtime of the operations and thus lowered overall workability due to squat phenomenon.

The majority of diffraction software is applying deepwater approach and can't acomodate the shallow water effect. Cause the velocity potential and derivatives is rather different between them, for example :

velocity potential of deepwater 

velocity potential of shallow water 

Can you tell me the steps of  modeling floating structure simulation in shalow water at MOSES?

Thanks,

Wibowo

Hi Wibowo,

Please see the following directory for the sample file "ob".  This shows the steps to model the obstacle option I mentioned in my earlier email.  The sample can be found at the following directory in the standard MOSES installation.

C:\Program Files\Bentley\Engineering\MOSES CONNECT Edition V11\hdesk\runs\tests\freq

The first option that I mention is the use of the "&env ename -depth" command.  The step is to type the command in the command file.

I hope this helps.

Georgina Maldonado

Georgina,

Thank you, I'll try it.

Wibowo

Georgina,

Thank you, I'll try it.

Wibowo