open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello, I am new to Artemis and having some difficulties trying to simulate wave reflection. I have used the example ile_para for reference and modified the version of borh used there, which sets the wave phase as far as I understand. I am able to simulate wave heights within my domain however there is no reflection from the solid boundaries. I thought I was looping through the boundary nodes and setting the reflection with

IF(JB.GE.562.AND.JB.LE.4481)THEN
RP%R(I)=1.D0

I have attached my borh file also. Could anyone offer some advice as to where I am going wrong?

Thanks

Oliver

Hello,

I don't understand why the line
C LIHBOR%I(I)=KLOG
is commented.
LIHBOR%I(I)=KLOG means that you have a wall.

You shouldn't comment it. Can you try to remove that?

Regards,

Christophe

Hello, yes sorry that should not be commented out, I was experimenting by saying LIHBOR%I(I)=2 to see if KLOG wasn't being implemented properly but forgot to change the fortran script completely before I uploaded it on here. I am printing out the assigned solid boundary values, which look correct, but I don't have any reflection

JB= 4477
I= 4477
LIHBOR= 2
RP= 1.0000000000000000
JB= 4478
I= 4478
LIHBOR= 2
RP= 1.0000000000000000
JB= 4479
I= 4479
LIHBOR= 2
RP= 1.0000000000000000
JB= 4480
I= 4480
LIHBOR= 2
RP= 1.0000000000000000
JB= 4481
I= 4481

Hi,

Which version of the code are you using?
In the current version, I have less points than you on the boundary.

You lso changed the wave direction from 90 to 220, did you make a try with 90 ?

What do you mean exactly by "I have no reflection"? Do you make the difference between incident wave field and reflected waves ?

Regards,

Christophe

Sorry, I should have mentioned that I have modified the ile_para test case to suit my case and mesh. I have been comparing the wave height results from the ile_para test case with my case. It is a similar set up, but I have multiple islands in my mesh. I have tried many different direcions(0,90,180) however I get the result where wave heights don't seem to be affected by the islands in the same way as in the ile_para test case. What do you mean by difference in incident wave field and reflected waves? I am outputting wave incidence in the result file and it does appear to show influence by the islands.

Regards

Oliver

Hello,

I am trying to simulate waves using Artemis around small hard structures, approximately 0.6m in diameter. I am simulating waves with a minimum period of 1s, maximum of 6s and peak of 4s. I am modifying the borh subroutine to specify wave height and direction at boundary nodes and also the reflective parameter at the hard structure nodes. Unfortunately I do not seem to get much response from wave heights using my hard structure with a diameter of 0.6m. I have made other test cases using a slightly larger square structure and a much larger rectangle, shown in the attached file. I get a significant response in the wave heights from the large rectangular structure (top panel) but nothing from my circular structure (bottom panel). I'm fairly new to artemis, so I'm trying to figure this out as I go, could someone offer some advice to me for this problem? Is there a minimum size of solid boundary which artemis will compute reflection, refraction and diffraction for?

Thanks

Oliver

Hello Oliver,

I never tried to do that in ARTEMIS but from a physical point of view, your 0.6m structure shouldn't pertub a lot the wave field. As your peak period is 4s, your typical wave length is about 25m. So your structure is really small compared to it...

Anyway, you can try to refine your mesh to be sure there nothing wrong with it. If you have experimental result on this specific case, you could try to look at the perturbations you should have and check your mesh is refined enough to capture them)

Regards

Christophe

Hello Christophe

Yes I expect the structure not to have a large impact on waves with a higher wave period. I am specifying a range of wave periods from 1 to 6s, however I take it the wave height in the artemis result file is an average of the whole spectrum. My mesh has a resolution of 2m at the boundary and 0.2m around the structure, which I thought would be sufficient. I have refined the mesh further to 0.1m around the structure but I now have a negative determinant, which I am trying to solve. Whilst I understand that the small structure should have the greatest influence on low period waves, I was expecting to see a greater influence on wave heights, especially when multiple small structures are included. I will continue to investigate.

Regards

Oliver