gambit lect 01

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Introductory GAMBIT Notes GAMBIT v2.0 Jan 2002

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Introduction to GAMBIT

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Agenda Day 18:00 Introduction + Demo

9:15 Tutorial 1: Creating and Meshing Basic Geometry

9:45 Creating Geometry in Gambit

10:45 Tutorial 2: Geometry Creation Exercises

12:00 Lunch

1:00 Edge/Face Meshing and Mesh Quality

2:00 Tutorial 3: Edge and Face Meshing Exercises

2:45 Volume Meshing and the Sizing Function

3:45 Tutorial 4: Volume Meshing and Sizing Function Exercises

4:30 Volume Decomposition Examples

5:00 Break for the Day

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Agenda Day 28:00 Tutorial 5: Volume

Decomposition Exercises

8:45 Mesh Control through Boundary Layers and Face Vertex Types

9:30 Tutorial 6: Vertex Types

10:30 CAD/CAE Import and Geometry Cleanup + Demo

11:30 Tutorial 7 or 8: Geometry Import Exercise

12:00 Lunch

1:00 Tutorial 7 or 8: Continued

1:30 Tutorial 9: Hex meshing the Flow Probe

3:00 Work on your own Project

1:00 Tutorial 7 or 8: Continued

1:30 G/Turbo + Demo

3:00 Work on your own Project

5:00 Break for the Day

or

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What is GAMBIT?

u A single, integrated preprocessor for CFD analysis:l Geometry construction and import

n Using ACIS solid modeling capabilitiesn Using STEP, Parasolid, IGES, etc. import

s Cleanup and modification of imported data

l Mesh generation for all Fluent solvers (including FIDAP and POLYFLOW)n Structured and Unstructured hexahedral, tetrahedral, pyramid, and prisms.

l Mesh quality examinationl Boundary zone assignment

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Operationu General sequence of operations

l Initial setupn Solver selection, Mesh size, Defaults, etc.

l Geometry Creation (ACIS, STEP, Parasolid, IGES or Mesh import)n Create full geometryn Decompose into mesh-able sections

l Meshingn Local meshing: Edge and Boundary layersn Global meshing: Face and/or Volume

l Mesh examinationl Zone assignment

n Continuum and Boundary attachmentl Mesh export

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Files (1)

u GAMBIT directory and filesl When GAMBIT starts up, it creates a directory called GAMBIT.#

n # = the process numbern It also creates a “lock” file, ident.lok, in the working directoryn ident.lok prevents any user from starting up another session using the

same identifier in the same directory. If the code crashes, this file needs tobe manually removed.

l Three files are created inside this directoryn ident.dbs =

n jou =

n trn =

the database. All information will be saved in thisfile. This file is NOT retrievable upon a crash

the journal file. This file is directly accessiblefrom the Run journal form

the transcript file. Output from GAMBIT

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Files (2)

u GAMBIT directory and filesl GAMBIT permanently saves these files to your working directory as

ident.dbs, ident.jou and ident.trn anytime you issue a “Save”option (equivalent to any standard word processor)n Upon Save, earlier versions of ident.dbs and ident.trn will be

overwritten, while new commands are appended to the file ident.joul Upon successful exit of GAMBIT:

n The directory GAMBIT.# is removedn The lock-file ident.lok is deleted

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Startup: DEMO

u Start gambit with“gambit filename”l NT Users must

start Gambit thisway from acommand prompt.

u Example: StartGambit in directory“projects”

u > gambit airfoil

Before save

After save

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Journal Files

u Journal File:l Executable list of Gambit commands

n Created automatically by Gambit from GUI and TUI.n Can be edited or created externally with text editor.

l Journals are small - easy to transfer, e-mail, store

u Uses:l Can be parameterized, comments can be addedl Easy recovery from a crash or power lossl edit existing commands to create new ones

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Running Journal Filesu Journal files can be processed in two ways:

l Batch mode (Run)n All commands processed without interruption.n “read pause” command will force interrupt with

resume option appearing.l Interactive mode (Edit/Run)

n Includes text editor for easy modificationss Mark lines in process field

to activate for processing.s Editable text field.s Right click text field

for more options.s Auto or Step through

activated process lines.

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Journal File: Parametric Modelingu Parameters (incl. arrays), control-blocks, do-loops, arithmetic functions,

etc., can be used in the Journal File for simplifying parametric studies.

Comment lines

Parameter namesbegin with $

Commands arenot case sensitive

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GUIMain Menu bar

Global Control

Operation toolpad

Command line Description window

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Operation Tool Pads

VertexEdgeFaceVolumeGroup

Boundary LayerEdgeFaceVolumeGroup

Boundary TypesBoundary EntityContinuum TypesContinuum Entity

Coordinate SystemsSizing FunctionG/TurboUser-Defined Tools

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File Menu (1)

u New, Open, Save, Save As and Exitl Standard form of database operations

u Print Graphicsl Prints graphics to printer or to filel PostScript, BMP, TIF, etc.

u Run Journal / Clean Journall Screen editor/command processor for journal filesl Command processing:

n Partial or global selection/de-selectionn Automatic or stepwise processing

l Ability to load the current journall File browserl Clean Journal removes unnecessary tags, undo’s, etc.

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File Menu (2)u View File

l View of the current output,ident.trn, thetranscript file

l Ability to view other files as well

u Importl ACIS, Parasolid -l IGES, STEPl ICEM Input, Vertex Datal CAD - Pro/E, Optegra Visualizer, I-DEAS FTLl Mesh - mesh and faceted geometry files.

u Exportl ACIS, Parasolidl IGES, STEPl Mesh - Export your mesh for your Solver.

n 2D option guarantees 2D mesh

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Edit Menu (1)

u Edit Titlel Title will be included on any printed graphics

u Edit Filel Ability to launch an editor within GAMBIT

u Edit Parametersl Ability to define, modify and list parameters

n parameters: $numeric = 10, n arrays: $array(3,4) = 5

l Parameters and arrays can also be directly defined inthe journal file using an editor (preferred option)

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Edit Menu (2)

u Edit Defaultsl Modify a large range of defaults that effect:

n User Environmentn Meshing Characteristicsn Geometry

l Ability to load, modify and save a new set of defaultsin $HOME/GAMBIT.ini which is loadedautomatically at startup.

u Undo/Redol Ten levels of undo/redo (default)l Reducing number of levels also reduces memory

requirements.

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Solver Menu

u The Solver selection will have an impact on thefollowing input forms:l Available meshing algorithmsl Available element typesl Continuum typesl Boundary typesl Export mesh file

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Graphical User Interfaceu Command:

l Input of (non-GUI) commands, e.g.,n reset: deletes all mesh and geometry in the current modeln reset mesh: deletes mesh, keeps geometry

u Descriptionl Gives a short description of all global function buttons and screen areas

u Transcriptl Output from GAMBIT is printed here as well as in ident.trnl Transcript window can be expanded using arrow button in top right corner

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Global Control (1)

Scale-to-Fit Pivot anchor forviewmanipulation

Four splitFour view

Light sourceSpecial LabelsAnnotate

Undo/Redo

Orient ModelJournal View

Modify (on/off) Label Visibility Rendering Show mesh Silhouette

Wire frameShadeHidden Line

Color coding Entity type Connectivity

Examine Mesh

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Global Control (2)u Scale-to-fit resizes the model to fit the screenu Orient Model - major axes , isometric and:

Reverse Previous

Journal view

u Select Pivot - around which the model rotates, zoomsBody centerMouse position

u Model display attributesl Turn on/off visibility, label, silhouette, mesh and hidden line on all or

selected geometrical entities

u Preset configuration of the graphics window4-view and 4-splitOptions to return to any single view

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Global Control (3)u The Window Attributes form

l Modify the following attributes (defaults given)n Render Wireframe on ; shaded and hidden offn Mesh Volume - offn Silhouette All onn Label All offn Visibility All on

l Two ways of picking entitiesn “All” - All entities are picked (Default)n “Pick” - Individual picking including

the use of pick lists

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Global (4)

u Render Model - Wireframe , Shaded , Hiddenu Modify Light/Label type

Change light source orientation and propertiesAdditional information on the entity labelInsert arrows and text for graphic presentations

u Color ModeColor by entityColor by connectivity

u Undo/Redo

u Examine Meshl Display different element types by quality, plane cuts, etc.

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Forms (1)u Form - components

l List box - (picking)n active (yellow) - ready to pickn inactive (white) - click to activate

l Radio buttonsn mutually exclusive options

l Option buttonn Option menu

l Text boxn Click-to-focus

l Check boxn non-mutually exclusive options

l Command buttons

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Forms (2)

u Text box

l Field for input of data, expressions, parametersl The cursor is blinking if active

n To activate - left click in the text box (click-to-focus)l Forms with several text boxes

n The order of input is not importantn Use “tab” to go to the next text boxn Use left click (click-to-focus) to go to any text box

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Forms (3)

u List boxl Highlighted in yellow if active

n To activate - left click in the list boxl Tells you the name of the latest picked item

n The item is highlighted in red on the screenn All previously picked items are pink

l Individual pick lists for each list boxl Forms with several list boxes:

n Depending on the form, the order of picking may be importantn Use Shift right-click to go to the next list boxn Use left click (in the list box) to go to any list box

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Forms (4)u Pick Lists

l Open the Pick List by clicking on the arrow

l The “Available” list is sorted in the order of pickingl Pick List functionality:

n Pick or Un-pick, Selected or All entities by highlightin left column and by clicking on the arrows

n Highlighted “picked” entities will appear red on thescreen

s edge.32, edge.33n Non-highlighted “picked” entities will appear pink

s edge.26, edge.28

n Right-click in lists area provides additional optionsn Filter can be used to control which objects are picked.

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Mouse Operations (1)Left Middle Right

Drag x-y rotation Translation Zoom/ z-rotation

Shift +Click

Pick Next Accept/Next picker

DoubleClick

Previous View Save view to journal

Ctrl Drag zoom Stretch zoom Click points to grid

You can toggle between picking with or without “Shift”:Keep right mouse button down while doing a “left-click”The cursor now changes to another symbolNow, Pick/Next/Accept do not need a “Shift”The Rotation/Translation/Zoom now needs a “Shift”

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Mouse Operations (2)u The picking philosophy: Left - Middle - Right

l Shift-Left: initial pickn Alternative: click and hold, drag diagonally to pick several items at the same

time - “window picking”n The latest pick is highlighted in red, previously picked items are highlighted

in pinkl Shift-Middle: modify pick

n The middle pick will behave differently depending on the mouse location:s Same: Cycle to the next available object within picking tolerances New: Replace last pick with new pick at new locations Bad: A Shift-Middle pick on “nothing” is equivalent to

“Un-select last pick”

l Shift-Right: Apply or go to the next list box

gambit lect 01

Documents

directory gambit

u gambit directory

geometry n

successful exit of gambit

mesh import n

polyflow n

fluent solvers

working directory n