Fluent Mesh file Format Simple description

Fluent mesh file is the default grid file of the fluent software, which mainly includes the geometric information of the mesh, divided into dimensions, nodes, faces, cells, zones and so on. The data of the Fluent mesh file is organized according to the structure of the Lisp statement, which is surrounded by parentheses and the beginning of the statement is generally an integer representing the type. such as the beginning of the file:

(0 "GAMBIT to Fluent File")

This is a comment statement in which the annotation type designator is 0 in the mesh file.

0. Notes on Nodes,faces,cells

From the bottom to the top level of the composition of the order of view, nodes formed faces,faces surround cells, and for the convenience of traversal faces and Cells,fluent introduced the face thread and cell thread, Thread can be viewed as a linked list structure of a link face or cell pointer

Nodes, faces, and cells

Cell thread

1. Dimensions (Grid dimension)

Label: 2

Format:

(2 ND)

where n is the dimension of the grid, which can be 2 or 3

Instance:

(0 "Dimension:") (2 2)

2. Nodes (node data)

Label: 10

Format:

(Zone-id first-index Last-index type ND) (x1 y1 z1 x2 y2 z2 ...))

* If zone-id=0, First-index will be 1,last-index equals the number of nodes, type is set to 1, ND is the grid dimension, followed by no coordinate data. This is equivalent to the overall description of the nodes

* If Zone-id is greater than 0, the nodes in the struct is part of the zone area of the numbered Zone-id. At this point First-index and Last-index are the node numbers for the zone area, and type is set to 1,nd as an optional parameter, representing the grid dimension. Node data does not display Z-coordinates when nd=2

Instance:

(1 1 C 1 2) (  & nbsp 0.0000000000e+000    0.0000000000e+000    2.0000000000e+000    0.0000000000e+000    6.6666666667e-001    0.0000000000e+000    1.3333333333e+000    0.0000000000e+000    2.0000000000e+000    1.0000000000e+000    0.0000000000e+000    1.0000000000e+000    1.3333333333e+000    1.0000000000e+000    6.6666666667e-001    1.0000000000e+000    2.0000000000e+000    5.0000000000e-001    0.0000000000e+000    5.0000000000e-001    6.6666666667e-001    5.0000000000e-001    1.3333333333e+000    5.0000000000e-001 ))

3. Faces (polygons and their threads)

Label: 13

Format:

(Zone-id first-index last-index bc-type face-type)

*zone-id=0, the statement describes the number of polygons (Last-index–first-index + 1) and does not write Bc-type

*zone-id is greater than 0 o'clock, the polygon thread number, Firt-index and Last-index are the boundary values of the polygon labels in the thread, respectively

*bc-type:

Bc-type	Decirption
2	Interior
3	Wall
4	Pressure-inlet,inlet-vent,intake-fan
5	Pressure-outlet,exhaust-fan,outlet-vent
7	Symmetry
8	Periodic-shadow
9	Pressure-far-field
10	Velocity-inlet
12	Periodic
14	Fan,porous-jump,radiator
20	Mass-flow-inlet
24	Interface
31	Parent (Hanging node)
36	Outflow
37	Axis

*face-type

TD valign= "Top" width= "> ";

< Em>face-type	description	Nodes/face
0	mixed
2	linear	2
3	triangular	3
4	quadrilateral	4
	polygonal	nn

Other data, each line represents a face:

N0 N1 n2 C0 C1

n represents the node number, N2 is not displayed for a 2-dimensional grid; The c* represents the adjacent cell number of the face, C0 is determined by the right-hand rule, C1 on the other side of the face, C0 or C1 at the border at 0.

* When the mesh is a mixed type, that is, face-type=0, the statement for each line description polygon should start with the number of nodes:

X n0 n1 ... nf C0 C1

X indicates the number of nodes on the polygon, and NF represents the last node.

4. Cells

Label: 12

Format:

(Zone-id first-index last-index type Element-type)

*zone-id=0, the statement is used to describe the number of cells, and if last-index=0 indicates that there is no cell in the file. Type=0,element-type not displayed

*zone-id is greater than 0 o'clock, which represents the cell thread,

Type = 4 for hex
Type = 2 for tet
Type = 5 for pyramid

Instance:

(0 "Faces:") (13 (0 1 11 0)) (13 (3 1 3 3 0) ( 2 5 7) 5 0 2 7 8) 3 0 2 8 6) 1 0 )) (13 (4 4 6 3 0) ( 2 1 3) 2 0 2 3 4) 4 0 2 4 2) 6 0 ))

5. Zones

Label: 45

Format:

((ID type name) ())

ID is area number

Type is types

Name is the zone name

Instance:

(0 "Zones:") (2 fluid fluid) ()) (3 wall up) ()) (Wall (4) ()) (5 pressure-outlet Outlet) ()) (6 Velocity-inlet Inlet) ()) (8 interior Default-interior) ())

6. Appendix-Completed MSH File

(0 "GAMBIT to Fluent File") (0 "Dimension:") (2 2) (1 1 C 1 2) (    0.0000000000e+000   ;  0.0000000000e+000    2.0000000000e+000    0.0000000000e+000    6.6666666667e-001    0.0000000000e+000    1.3333333333e+000    0.0000000000e+000    2.0000000000e+000    1.0000000000e+000    0.0000000000e+000    1.0000000000e+000    1.3333333333e+000    1.0000000000e+000    6.6666666667e-001    1.0000000000e+000    2.0000000000e+000    5.0000000000e-001    0.0000000000e+000    5.0000000000e-001    6.6666666667e-001    5.0000000000e-001    1.3333333333e+000    5.0000000000e-001 ) (0 "Faces:") (13 (0 1 11 0)) (13 (3 1 3 3 0) ( 2 5 7) 5 0 2 7 8) 3 0 2 8 6) 1 0 )) (13 (4 4 6 3 0) ( 2 1 3) 2 0 2 3 4) 4 0 2 4 2) 6 0 )) (13 (5 7 8 5 0) ( 2 2 9) 6 0 2 9 5) 5 0 )) (6 9 A 0) ( 2 6 a 1 0 2 a 1 2 0 )) (8 B 11 2 0) ( 2 A B 1 2 2 B 8 1 3 2 3 B 2 4 2 b c 3 4 2 C 7 3 5 2 4 C 4 6 2 C 9 5 6 )) (0 "Cells:") (12 (0 1 6 0)) (12 (2 1 6 1 3)) (0 "Zones:") (2 fluid fluid) ()) (3 wall up) ()) (Wall (4) ()) (5 pressure-outlet Outlet) ()) (6 Velocity-inlet Inlet) ()) (8 interior Default-interior) ())

Fluent Mesh file Format Simple description