Search found 7 matches

by hola
11 Aug 2013, 17:17
Forum: ElmerSolver
Topic: k-epsilon parameter setting in Elmer
Replies: 0
Views: 951

k-epsilon parameter setting in Elmer

Helo, I'm uncertain about how to set k-epsilon parameters in Elmer. Short overview: Turbulent kinetic energy: ([0.16*Re^(-1/8)]^2 ) * 1.5 dissipation: [k^1.5/(characteristic length)] * (model constant=0.09) reference source: http://www.cfd-online.com/Wiki/Turbulence_free-stream_boundary_conditions s...
by hola
21 Jun 2013, 11:23
Forum: ElmerSolver
Topic: Actuator Disk Pressure Boundary Condition?
Replies: 4
Views: 2286

Re: Actuator Disk Pressure Boundary Condition?

Hi, here are the first images, crude mesh only. I had problems with finer resolution (really), and I still have to find a workaround for the "leak" visible in the hemisphere version, so these are just previews. I know that the momentum theory prescribes the neccessary dI/dt for the given reaction fo...
by hola
18 Jun 2013, 15:56
Forum: ElmerSolver
Topic: Actuator Disk Pressure Boundary Condition?
Replies: 4
Views: 2286

Re: Actuator Disk Pressure Boundary Condition?

Hi, many thanks for your help, I'll try them out. Actually, I've already found the External Pressure and Pressure <1|2|3> options. I tried them, and they worked, albeit not perfectly. I had a problem with discretization, just as you'd predicted. The meshing gave the best result when the resolution w...
by hola
13 Jun 2013, 14:35
Forum: ElmerSolver
Topic: Actuator Disk Pressure Boundary Condition?
Replies: 4
Views: 2286

Re: Actuator Disk Pressure Boundary Condition?

In the meanwhile, I thought of specifying the pressure jump condition on a permeable surface by MATC. Is it possible? Maybe in a tangential coordinate system, an expression takes the pressure a small distance away in normal direction, and adds the pressure jump to it, then sets this new pressure as ...
by hola
11 Jun 2013, 15:34
Forum: External tools
Topic: Gmsh planar surface building crash
Replies: 3
Views: 2364

Re: Gmsh planar surface building crash

Right now I can't send you files, but it's just 3 points, and 3 lines between them.
I use the 2.7.1 version. Thank you for the link, I'll ask this there.

Bye
by hola
11 Jun 2013, 15:24
Forum: External tools
Topic: Gmsh planar surface building crash
Replies: 3
Views: 2364

Gmsh planar surface building crash

Hi, I'm new in Gmsh and in Elmer. I'm trying to build simple geometries in Gmsh, and when I arrive at defining a planar surface by its boundaries, Gmsh crashes. (Viewport prompt: "Select hole boundaries (if none, press 'e')"). Right after I press 'e', it crashes. In this case, the boundaries are lin...
by hola
11 Jun 2013, 14:33
Forum: ElmerSolver
Topic: Actuator Disk Pressure Boundary Condition?
Replies: 4
Views: 2286

Actuator Disk Pressure Boundary Condition?

I'd like to model a fan with an infinitely thin disk with a prescribed pressure jump (http://en.wikipedia.org/wiki/Actuator_disk). How can I set a pressure difference
boundary condition in Elmer?