© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Volume Decomposition Examples

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Decomposition  Suggestions of how to decompose single volumes into multiple mesh-able volumes are shown in these examples.  The following meshing tools are used: Map Submap Tet-primitive Cooper  Volume decomposition is not needed for the Stairstep or TGrid tet/hybrid meshing schemes.

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center First Example (1)  A spherical void inside a brick Construction Create a sphere, a brick and a cylinder using volume primitives. The cylinder diameter should be smaller than the sphere and its length extending outside the brick Subtract the sphere from the brick Decomposition Split the brick using the cylinder Create edges going diagonally over the top and bottom face of the brick and use the edges to create a diagonal face Split the brick-like volume using this face s Last two steps are not necessary but create higher quality mesh.

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center First Example (2) A spherical void inside a brick Three of the four Cooper-able volumes source faces

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Second Example (1) A handle Construction: s Create a torus and a brick using volume primitives s Split the torus using the brick Face as a tool s Delete the left part of the torus Decomposition: s Make a Bidirectional split of the remaining volumes

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Second Example (2) A handle Alternative Construction/Decomposition: s Create a torus and a brick using volume primitives s Perform a bi-directional split using the two volumes s Delete the part of the torus that is outside the back of the brick s Unite back the block and the pipe section inside the block again

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Second Example (3) A handle The two volumes meshed by the Cooper - tool source faces source face

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Third Example (1) A box with rounded corners Construction s Create a brick using volume primitives s Use the blend option to round off one corner and three edges using the same radius (Setback option) Decomposition: s Create a second brick of the same size as the radius of the blend and move it such that its corner coincides with the center point of the blended corner. s Split off the the rounded corner s Sweep out the three triangular faces created by the split to the opposite ends of the brick s Split off the three prismatic volumes from the main volume

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Third Example (2) A box with rounded corners The volume can be meshed using the submap (1), the tet-primitive (not shown) and the Cooper (3) schemes. source faces source face

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Fourth Example (1) Pipe-pipe intersection (different radii) Construction: s Create the pipes using volume primitives s Create a stretched brick with a rectangular cross-section, where the side length should be between the two pipe diameters. Decomposition s Split the main pipe using the brick s Unite the brick cut-out with the small cylinder

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Fourth Example (2) Pipe-pipe intersection (different radii) The three volumes meshed using the Cooper tool source faces

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Fifth Example (1) A sphere in three volumes Construction s Create a sphere using volume primitives Decomposition: s Create a cylinder and split the sphere using the cylinder s Create a brick and move it such that one side of the brick is along the center of the cylinder s Split the annular remainder of the sphere into two volumes s All three volumes are basic Cooper-able volumes

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Fifth Example (2) A sphere The final mesh for two of the volumes source faces

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Fifth Example (3) A sphere in eight volumes Alternative Construction/decomposition s Create a sphere and a brick using volume primitives s Intersect the two volumes to create a sphere octant s Make a second copy by the use of Copy/Reflect and the z-plane s Make six octants more using Copy/Rotate and 90 degree angle, twice s Connect all faces using Real Connect The same geometry could also have been created by splitting a sphere in all three major planes This decomposition will create a better mesh quality

© Fluent Inc. 10/24/ Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002 Fluent User Services Center Fifth Example (4) A sphere The final mesh for seven out of the eight octants, all meshed using Tet Primitive