lheea / nemoh Goto Github PK

Hello! I've been working on a project which requires the use of NEMOH. Since I am completely new to it, I thought of running the vertical cylinder example given in the NEMOH folder. On trying to run the Matlab code Nemoh.m, I receive the following error:
------ Starting NEMOH -----------
At line 138 of file preProcessor/Main.f90 (unit = 10, file = './Nemoh.cal')
Fortran runtime error: Bad integer for item 1 in list input

Error termination. Backtrace:
#0 0x10208b757
#1 0x10208c3db
#2 0x10208cd73
#3 0x10214d907
#4 0x10215016b
#5 0x102150c2f
#6 0x10206fb4b
#7 0x10207252f
------ Solving BVPs -------------

-> Initialisation At line 73 of file Solver/Core/Bodyconditions.f90 (unit = 10, file = './Normalvelocities.dat')
Fortran runtime error: End of file

Error termination. Backtrace:
#0 0x1050cb757
#1 0x1050cc3db
#2 0x1050ccd73
#3 0x105195f83
#4 0x1051900d7
#5 0x105190c2f
#6 0x104e3693f
#7 0x104e4a947
#8 0x104e4c22f
------ Postprocessing results ---

-> Initialisation .At line 113 of file Common/Results.f90 (unit = 10, file = './results/index.dat')
Fortran runtime error: End of file

Error termination. Backtrace:
#0 0x102f5b757
#1 0x102f5c3db
#2 0x102f5cd73
#3 0x103025f83
#4 0x1030200d7
#5 0x103020c2f
#6 0x102f45433
#7 0x102f497f3
#8 0x102f49b9f

I don't know if it is relevant, but I am running the code on macOS Big Sur and have used the makefile as per the instructions. Looking forward to hearing your thoughts and advices!

Cheers,
Rohit

Hi all,
I downloaded Nemoh from the LHEEA website.
I am trying to run it from a Linux OS.
First I tried to use the makefile but there is an issue in the mesh.f90 file :
" **>> USE MIdentification

Fatal Error : can't open module file 'midentification.mod' for reading at (1) : no such file or directory**"

Do you have any idea how I can fix this ?

thanks !

Dear all,
I use nemoh to calculate the Hydrodynamic coefficients between bodies. But when i check the results in BEMRosetta after the nemoh was done, i found that the second body's excitation force and diffraction scattering force are zero. But the first body's Hydrodynamic coefficients are normal. Here is my .cal and the results.

Any suggestion?

Thanks.

Regards

Hello there, so I am trying to use Nemoh to find my coefficients for a sphere for use in WEC-sim. I used BEMROSETTA to convert my STL files into NEMOH.dat file for input into NEMOH and then planned to use the coefficients obtained from NEMOH in WEC-Sim for analysis of my device.

However, when I run Nemoh through MATLAB, I get the same error. full error below

Error using fgets
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in fgetl (line 32)
[tline,lt] = fgets(fid);

Error in Nemoh (line 104)
ligne=fgetl(fid);

Error in nemoh_run (line 9)
[A,B,Fe]=Nemoh(w,dir,depth);

Is there any guide on using an already mesh and running nemoh.

Hi, I tried implementing the code, but I keep getting the mentioned error. It could have something to do with the file path being created to store all the results. I am quite new to MATLAB, so I was wondering if anyone could help me out.

The complete error looks like this:

Error using fscanf
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in ax_mesh>AxiMesh (line 105)
ligne=fscanf(fid,'%s',2);

Error in ax_mesh (line 25)
[Mass, Inertia, KHyd, XB,YB,ZB] = AxiMesh(r,z,n)

Hi I am getting a new error. It seems that certain values are coming to be smaller than 1 in the x y z variables. Could anyine please guide me through this

Hello all,
I would appreciate if someone can help me with the below issue. In order to run Bemio, It needs hydrostatic.dat and kh.dat file from NEMOH.
I tried to run the WEC-Sim BEMIO code (bemio.m) for Nemoh. It has four files in mesh folder (WEC-Sim-examples-BEMIO-NEMOH-RM3-Mesh) called hydrostatic_0.dat, hydrostatic_1.dat, KH_0.dat and KH_1.dat so it is running fine. But when I am trying to run NEMOH for my object then it is not creating above four files and due to that I am unable to run the code on my geometry. Is there any change needed in Nemoh.cal or Mesh.cal file to generate these files or somewhere else. I am sorry but I am just a beginner and finding difficulty in running NEMOH due to less documentation available.

Below are the files NEMOH code is generating in Mesh and folder.

Below are the files NEMOH code is generating in Result folder.

And bemio.m code is giving me below error:

Can somebody guide me how can I create hydrostatic.dat and kh.dat file from NEMOH?
Thanks in advance

Dear developers,

is it possible to use triangles combined with quadrilaterals in a mesh?

kind regards

Roberto

Hello, I want to compare added mass and damping results for different number of panels. does anyone has a Matlab prepared script to plot only added mass and damping from nemoh or bemio result.

Dear all

Hi, I want to use Nemoh to calculate the freesurrface elevation. And i get 7 files about free surface of each problem under one

frequency.

And, I want to know how to calculate the real free surface elevation. By summing them all?

Can anyone tell me. And thank you all guys!

G

Hi all,
I would like to investigate a flexible plate floating on water surface. I saw the introduction that the Nemoh has the ability to deal with hydroelasticity problem. But I can not find any further information. Can you share an example about it?
Many thanks in advance.

Hello all,

I have investigated the results of NEMOH (and HAMS) compared to WAMIT by OC3 Hywind Spar and OC4 DeepCWind semisubmersible. My overall results are quite good; however, I obtain irrelevant results in the pitch axis for both of the cases. I could not be able to access the NEMOH forum or find any guide.

I have attached the comparison, and here is my study:
https://www.researchgate.net/publication/356129613_Comparison_and_Evaluation_of_Open-Source_Panel_Method_Codes_against_Commercial_Codes

I am in search of a guide
Thanks in advance,

OC3 Hywind:

OC4 DeepCWind:

Hello, I would like to plot the wave elevation solved by nemoh. Can someone explain how to go about this.

Dear all,

Does anyone know how to acquire diffraction and excitation IRFs from Nemoh and how to convert diffraction and excitation forces to time domain? Nemoh provides DiffractionForce, ExcitationForce, and FKForce in frequency domain. I am wondering how to convert them to time domain. From the literature, the excitation force in time domain can be obtained using (for regular wave):

F_ex(t) = R{ H/2 * F_ex(w) * exp(iwt) },

where H is the wave height, w is the wave frequency, R is to extract the real part, i is the imaginary unit, F_ex(w) and F_ex(t) are excitation forces in frequency and time domains, respectively.

However, I do not know how to convert the diffraction force to time domain. I am aware of that excitation force is the sum of diffraction force and FK force. So, does that mean I can obtain their time domain counterparts through the following linear decomposition?

F_ex(w) = F_d(w) + F_fk(w),
F_d(t) = R{ H/2 * F_d(w) * exp(iwt) },
F_fk(t) = R{ H/2 * F_fk(w) * exp(iwt) },

I am not sure. All these forces have their phase angles according to the result files generated by Nemoh, how to involve them in the conversion?

Besides, I am also thinking of acquiring the IRFs of diffraction and excitation forces. Nemoh only gives the IRF of radiation force directly. How to obtain the other two? I intend to use them in a time-domain analysis. Knowing the IRF, the diffraction and excitation forces in time domain can also be obtained using:

F(t) = - integral { K(t-tau) * eta(t) } dt

where K(t) is the IRFs, eta(t) is the free-surface elevation.

Any suggestion?

Thanks.

Regards,
Zander