Modifying the Grid in Fluent
Purpo : This document describes veral commonly ud operations that can be performed to modify the grid after it has been read into FLUENT . Face and cell zone bad operations are described along with their us and limitations.
送苹果Introduction
All grid and zone bad operations are usually performed in GAMBIT . However, it is sometimes convenient to manipulate the grid in FLUENT itlf. Some common situations are: • Scaling, rotating or translating the grid
• Separating a single boundary zone into multiple zones for specifying different boundary conditions • Removing one or more unwanted cell zones from the mesh
Grid Operations
FLUENT assumes that the grid is generated in SI units. Grid modifying operations that can be performed are:
Operation Description Usage/Application
Scale
• Each node location is multiplied by supplied
scaling factor.
•
It is possible to provide different scale factors for each axis.
• When grid is not created in SI units. • To change physical size of the domain.
• Non-uniform scaling will change aspect ratio of the cells.
Translate • Each node is translated by offt values prescribed along coordinate axes.
• Nodes are displaced in existing unit of length.
Rotate
• Each node is rotated by prescribed angle about the axis specified.
• Current unit of angle is ud for rotation. • Rotation origin can be different from the coordinate system origin.
• In axi-symmetric tup, when axis of rotation does not coincide with x-axis.
继续跳舞• For rotating zone problem, if grid has axis of rotation that does not pass through origin. • To relocate the domain for simplification of post processing operations.
Note: The domain extents will be updated to display the new range after each grid operation.治疗尿路感染的药
Zone Operations
• Merging Zones
A large number of zones with identical boundary conditions may exist in a mesh file. For efficient ca tup and post-processing, the zones can be combined to form a single zone. Cell zones should be merged before merging the face zones. Be aware that the merging process may not be fully reversible.
• Separating Zones
This operation is ud to split a boundary or continuum zone into multiple zones. The zone type and boundary conditions are prerved for all newly created zones.
Face Zone options: Various face zone options are shown in the table below.
Separation Type Before Operation After Operation
Angle: This option requires an angle as an
input. If the angle between adjacent face
normals is greater than or equal to the
specified angle, the faces will be parated
to form different zones.
Face: This option parates a single
boundary zone into a number of distinct
mesh elemental faces. For example, a
boundary with 10 elemental faces will be
split into 10 different zones. This option is
not commonly ud, as it results in a large
学业规划number of zones.
Mark: Cells can be grouped to form
registers using the adapt feature. Further,
face zones can be parated using the
marked registers.虎耳草的功效
Region: The mesh may contain
disconnected entities in a single boundary
zone. Region bad paration creates a new
boundary zone for each disconnected face.
Face zones that are continuously connected
are placed in a single zone.
Cell Zone options:Operations for parating cell zones are very similar to that of face zones. Only Mark and Region options are available for parating cell zones.
• Other Zone Operations
Deactivating:A particular cell zone can
be ignored during the simulation by its
deactivation. This operation will parate
all common interior face zones forming
施工进度计划表范本
wall and/or wall-shadow boundary types.
No equations are solved in deactivated cell
zones. However, the previous solution
data is prerved.
Activating:Any deactivated cell zone can be reactivated using this operation. If there were no previously deactivated zones, then no zone will be available for activation. It is possible to restore the previous solution data on the reactivated zone. It is important to t the correct boundary conditions for wall/wall-shadows zones after reactivation.
Deleting:It is possible to delete any cell zone. This operation is uful if a particular part of the domain is irrelevant for the prent simulation. Deletion is usually a two step process. The first step is to parate the irrelevant portion from the existing cell zone. The next step is to delete the parated zone.
Note: It is not possible to retrieve the deleted zone.
• Fusing Face Zones
绿萝用什么土
If there are two disconnected cell zones, their interction will have duplicate nodes and faces. The fusing face zone operation can be ud to connect the two cell zones. The grid node locations may not be identical at the boundaries where the two zones meet. If there is a slight difference in the node locations of the two zones, then the tolerance can be incread. Note that very large tolerance values may result in
a distorted mesh.
Notes and Tips
• It is recommended that you save a new ca file after performing any zone bad paration. The data file also needs to be saved as the results are automatically assigned to appropriate zones.perform
• Zone paration cannot be performed on mesh zones that contain hanging nodes. Hence, the operations are to be performed prior to using hanging node bad adaption.
• It is possible to check the outcome of a paration method by using the Report option without actually performing the paration.
• The step-by-step procedure for all the grid and zone bad operations is available at: Modifying the
Grid
Product Version:Fluent 6.2 and onwards
Authors:Jayesh Mutyal and Ashish Kulkarni
