Search found 25 matches

by martijn
12 Apr 2010, 18:10
Forum: ElmerSolver
Topic: NS solver: sign of the pressure.
Replies: 4
Views: 1799

Re: NS solver: sign of the pressure.

I have been able to work arround this problem by specifying the size of the pressure commonents instead of defining an external pressure. So it works, the I still would like to know the cause.
by martijn
06 Apr 2010, 13:47
Forum: ElmerSolver
Topic: NS solver: sign of the pressure.
Replies: 4
Views: 1799

Re: NS solver: sign of the pressure.

Hi Peter and all the others, The signs of the pressure gradient and velocity are consistent. I just don't understand why the pressure is negative while I defined it positive in the SIF file: Header CHECK KEYWORDS Warn Mesh DB "." "." Include Path "" Results Directory "" End Simulation Max Output Lev...
by martijn
02 Apr 2010, 13:45
Forum: ElmerSolver
Topic: NS solver: sign of the pressure.
Replies: 4
Views: 1799

NS solver: sign of the pressure.

Hi, I made a simulation of the air flow in a cylindrical gap. High pressure (500000Pa) in the centre (@0.1mm), low pressure (100000) at the edge (@3.5mm). The simulations results are shown below. The results show that the signs of the pressure and consequently the flow direction are reversed. Air is...
by martijn
02 Apr 2010, 13:36
Forum: ElmerSolver
Topic: problem NS equation in cylindrical coordinates
Replies: 5
Views: 2981

Re: problem NS equation in cylindrical coordinates

Thanks, this solved the problem. In my opinion the names of the geometries are unclear. I would therefore like to suggest the names: cylindrical (with azimuth component) and cylindrical (without azimuth component). Where are the geometries and the order of the coordinates described in the documentat...
by martijn
30 Mar 2010, 17:32
Forum: ElmerSolver
Topic: problem NS equation in cylindrical coordinates
Replies: 5
Views: 2981

Re: problem with cylindrical coordinates

When I decrease the average inlet velocity from 1 m/s to 0.1 m/s, the results agree with my expectations. See below.
What causes Elmer to create the azimuthal velocity component at higher flow speeds? How to suppress this? I would like to increase the velocity to much higher values than 1.
good.png
good.png (36.01 KiB) Viewed 2611 times
by martijn
30 Mar 2010, 17:19
Forum: ElmerSolver
Topic: problem NS equation in cylindrical coordinates
Replies: 5
Views: 2981

problem NS equation in cylindrical coordinates

I am trying to model an azimuth independ flow, os V(r,z) = (vr(r,z), vz(r,z)) The mesh I generated represents a crossection of an ring between r=r0 and r1 and z=0..h There are rigid walls at r=r0 and z=0. In the corner between those wall, at r,z=r0,h, an air jet with a anverage velocity of 1m/s ente...
by martijn
05 Jan 2010, 18:21
Forum: ElmerSolver
Topic: convert ep -> vtk
Replies: 1
Views: 1740

convert ep -> vtk

Hi, After running a simulation that took a few hours, the vtk file created by the ResultOutput solver appears to be corrupt. (see attachment), though the ep files are fine. Is there a way to convert the ep file to a vtk without running the simulation again? The problem appears to be in only one part...
by martijn
11 Dec 2009, 18:38
Forum: Installation & compilation
Topic: Compiling Elmer with MPI
Replies: 23
Views: 14685

Re: Compiling Elmer with MPI

Hi I have problems with the compilation of Elmer in combination with mpi. I call configure with: --enable-mpi --with-mpi-dir=/usr/lib/openmpi I am running Ubuntu 9.10 with the openmpi 1.3 package shipped with the distro. Compilation of the fem module with mpi fails. The config.log says: /usr/local/f...
by martijn
11 Dec 2009, 00:58
Forum: ElmerSolver
Topic: Elastic solver: displacement not in vtk file
Replies: 4
Views: 2546

Re: Elastic solver: displacement not in vtk file

Thanks, option b worked for me, after I made sure that the solvers were mentioned in the correct order in the equation section.
by martijn
10 Dec 2009, 19:32
Forum: ElmerSolver
Topic: Elastic solver: displacement not in vtk file
Replies: 4
Views: 2546

Re: Elastic solver: displacement not in vtk file

The relevant part of the SIF file is shown below. The full file has been attached.

Martijn