CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[snappyHexMesh] Suggestions for meshing (snappyHexMesh)

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 15, 2024, 22:39
Question Suggestions for meshing (snappyHexMesh)
  #1
Senior Member
 
Kumaresh
Join Date: Oct 2016
Posts: 349
Rep Power: 11
Kummi is on a distinguished road
Send a message via Yahoo to Kummi
Hello everyone,

I am currently working with my gas turbine combustor model. I need some suggestions for meshing the current model. I am hereby going to explain, what I have tried until now.
1) To do an internal mesh using snappyHexMesh, I created a box around my actual geometry. (Fig. 1. Computational domain inside the box)
2) Then, based on fixing appropriate coordinates in locationInMesh, I could able to create an internal mesh (Fig. 2. Internal mesh in the combustor). The mesh is not fine in center of combustor regime with still little distortion in domain shape.
3) One of my friends recommend me to use STAR CCM+ for good mesh with quick adaptability that saves time (Fig. 3. Mesh in STAR CCM+). However, I prefer using snappyHexMesh or any other open-source tools in order to understand the art of meshing. I would like to learn things perfectly, even though it can take a while at times.


I would like to know the following:
1) May I ask if the above steps I am following step-by-step are correct? I need to play with as many parameters that are present in snappyHexMeshDict file to get my expected mesh.
2) Can someone suggest me snappyHexMesh learning tutorials ?
3) Or should I need to adopt other opensource tools like GMSH (or) Salome ?
Thank you
Kindly correct me and give some valuable suggestions.
Attached Images
File Type: jpg Fig. 1. Computational domain inside the box.JPG (82.1 KB, 22 views)
File Type: jpg Fig. 2. Internal mesh in the combustor.jpg (83.2 KB, 20 views)
File Type: jpg Fig. 3. Mesh in STAR CCM+.jpg (143.5 KB, 19 views)
Kummi is offline   Reply With Quote

Old   April 22, 2024, 21:22
Default
  #2
Senior Member
 
Kumaresh
Join Date: Oct 2016
Posts: 349
Rep Power: 11
Kummi is on a distinguished road
Send a message via Yahoo to Kummi
I played with snappyHexMesh parameters and got a reasonable mesh.

Quote:
castellatedMesh true;
snap true;
addLayers false; // no need to add layers in the present problem
Quote:
geometry
{
Combustor_15thApril.stl
{
type closedTriSurfaceMesh; //closedTriSurfaceMesh;
name Combustor;
}
cylinder_cone_and_swirler
{
type searchableCylinder;
point1 (0 0 50);
point2 (0 0 85);
radius 12.85;
}
cylinder_fuel_injection
{
type searchableCylinder;
point1 (0 0 65); //(-1.5 -1.5 65)
point2 (0 0 90); //(1.5 1.5 90);
radius 2; //1.5; 1.375; //0.5; //0.89
}
box_combustor
{
type searchableBox;
min (-25 -25 85); //(-20 -35 85); //(-35 -35 85);//(-15 0 90);
max (25 25 120); //(20 35 110); //(35 35 120); //(15 0 110);
}
};
Quote:
castellatedMeshControls
{
castellatedMesh true;
snap true;
addLayers false;
refinementSurfaces // Global refinement
{
Combustor
{
level (1 1); //this is necessary to patch the internal (flow) patch
}
}
refinementRegions // LOCAL refinement
{
cylinder_cone_and_swirler
{
mode inside;
levels ((2 2)); //((2 2));
}

cylinder_fuel_injection
{
mode inside;
levels ((2 2));
}

box_combustor
{
mode inside; //2 million
levels ((2 2));
}
}
locationInMesh (1e-5 1e-5 200);
allowFreeStandingZoneFaces false;
features ( ); // EDGE refinement
resolveFeatureAngle 30;
}
Quote:
snapControls
{
nSmoothPatch 1; //5 - Aspect ratio increased to 10 // 3 was kept default (AS - 7.8, Skew = 3.17) // 1 --> (AS - 5.72, Skew = 2.89)
tolerance 2.0;
nSolveIter 30; //50 - no changes, 30 is better
nRelaxIter 20 //10; //5; // recommended
//nRelaxIter 10; 20; - improved
nFeatureSnapIter 10; // recommended
//nFeatureSnapIter 20; 50; 100; //improved
implicitFeatureSnap false;
explicitFeatureSnap true;
multiRegionFeatureSnap true;
}

Hope this helps someone.

Thank you
Attached Images
File Type: jpg Final_fullModel.jpg (90.1 KB, 7 views)
File Type: jpg Cross_section.jpg (89.7 KB, 8 views)
Kummi is offline   Reply With Quote

Reply

Tags
gasturbinecombustor, snappyhexmesh

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
PROBLEM USING rhoCentralFoam AND snappyHexMesh davidvzq OpenFOAM Running, Solving & CFD 0 May 27, 2021 00:01
[snappyHexMesh] snappyHexMesh running lguillem OpenFOAM Meshing & Mesh Conversion 7 June 13, 2014 11:28
[snappyHexMesh] Error in SnappyHexMesh gooya_kabir OpenFOAM Meshing & Mesh Conversion 2 October 23, 2013 04:41
[snappyHexMesh] SnappyHexMesh samiam1000 OpenFOAM Meshing & Mesh Conversion 0 October 5, 2009 10:32
[snappyHexMesh] Problem with snappyHexMesh samiam1000 OpenFOAM Meshing & Mesh Conversion 0 October 3, 2009 05:08


All times are GMT -4. The time now is 06:57.