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Limit of Porous Plate's Closs

Eduardo G-Gorbeña, modified 6 Years ago.

Limit of Porous Plate's Closs

Youngling Posts: 5 Join Date: 8/8/14 Recent Posts
Hi all,

I want to model the effect of a tidal current turbine on hydrodynamics. I'm doing it modelling the tidal turbine as a porous plate. Assessing the simulation results, I notice that once you pass a threshold you can increase the value of Closs that it won´t generate an additional head loss (i.e. results for Closs = 100 are the same as for Closs = 1000). Even though I use a large Closs the flow through the cell is not complety block.

Does anyone know how I can change this limit?

Regards,

Eduardo
porous plate .ppl
Phil Shepperd, modified 6 Years ago.

RE: Limit of Porous Plate's Closs

Youngling Posts: 10 Join Date: 5/31/11 Recent Posts
Hi Eduardo. While not specifically answering your question ....... I managed to calibrate Closs against some downstream flow speeds provided by my client, with the Closs values ending up <1, not 100 and i agree that the flow reduction diminishes as Closs increases. All worked fine when flow was perpendicular to the plate, but when i tried putting the flow at ~45 degrees to the plate, the wake recovery was way to quick, even with plates in both the M and N directions. In the end this was got round by putting plates in the cells either side of the cell in question, with Closs = 0.00001. Not sure what was gong on, but it worked well.
Eduardo G-Gorbeña, modified 6 Years ago.

RE: Limit of Porous Plate's Closs

Youngling Posts: 5 Join Date: 8/8/14 Recent Posts
Hi Phil,

Thank you for sharing your experience using poous plates, It is good to know how you solved the issue regarding oblique flows.

Regards,

Eduardo
luna terra, modified 1 Year ago.

RE: Limit of Porous Plate's Closs

Youngling Posts: 2 Join Date: 10/18/22 Recent Posts
The tips shared are really effective for me personally. Thank you! 
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