| sturgeon |
June 27, 2018 19:40 |
Issues replicating a mesh
Hi all
I'm trying to replicate the results of this paper: https://www.sciencedirect.com/scienc...60132316300208
From the results section, discussing the second of the two meshes created, they state:
Quote:
The first mesh is 0.1 m above the underlying surface to fulfill the requirement of y*. The grid size in the vertical direction increases with a ratio of 1.05 until the grid is 50 m, and the grid remains 50 m from there to the top of the domain. The x-grid in and near the city region (−0.6 ≤ x/D ≤ 0.6) is set to 100 m to obtain detailed characteristics compared to the mesoscale model, and it is uniform. The x-grid far away from the city area (x/D> 1.4) is not as crucial, so the x-grid there is set to 500 m. Between these two regions, the x-grid increases from the city area to the direction outside the city with a ratio of 1.05, until the grid reaches 500 m.
|
I believe I have replciated the mesh faithfully using blockMesh:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: plus |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
convertToMeters 1000;
vertices
(
(0 0 0)//0
(6 0 0)//1
(14 0 0)//2
(55 0 0)//3
(0 0 0.98)//4
(6 0 0.98)//5
(14 0 0.98)//6
(55 0 0.98)//7
(0 0 2.98)//8
(6 0 2.98)//9
(14 0 2.98)//10
(55 0 2.98)//11
(0 1 0)//12
(6 1 0)//13
(14 1 0)//14
(55 1 0)//15
(0 1 0.98 )//16
(6 1 0.98 )//17
(14 1 0.98)//18
(55 1 0.98 )//19
(0 1 2.98)//20
(6 1 2.98)//21
(14 1 2.98)//22
(55 1 2.98)//23
);
blocks
(
hex (0 1 13 12 4 5 17 16) (60 1 127) simpleGrading (1 1 500)
hex (1 2 14 13 5 6 18 17) (29 1 127) simpleGrading (5 1 500)
hex (2 3 15 14 6 7 19 18) (82 1 127) simpleGrading (1 1 500)
hex (4 5 17 16 8 9 21 20) (60 1 40) simpleGrading (1 1 1)
hex (5 6 18 17 9 10 22 21) (29 1 40) simpleGrading (5 1 1)
hex (6 7 19 18 10 11 23 22) (82 1 40) simpleGrading (1 1 1)
);
edges
(
);
boundary
(
floor
{
type wall;
faces
(
(0 1 13 12)
(1 2 14 13)
(2 3 15 14)
);
}
ceiling
{
type patch;
faces
(
(8 9 21 20)
(9 10 22 21)
(10 11 23 22)
);
}
fixedWallsX1
{
type patch;
faces
(
(0 12 16 4)
(4 16 20 8)
);
}
fixedWallsX2
{
type patch;
faces
(
(3 15 19 7)
(7 19 23 11)
);
}
);
mergePatchPairs
(
);
// ************************************************************************* //
However, my results are fairly poor. When I set the bottom boundary as homogeneous heat transfer, the results across the left where the domain is more refined is vastly different to the other areas, and when I use checkMesh, I fail two mesh checks. Max aspect ratio is 5829, with number of cells 3486, and there are 8311 underdetermined cells.
The work I am trying to replicate was done in Fluent - is there some reason that OpenFOAM can't work with a mesh like this, or is this mesh in fact fine? |
