Stanford的fluent课件_Command files for parametric studies

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Example of Automatic Adaptation
Initial Grid: 100 elements
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Final Grid: 40,000 elements
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Example of Automatic Adaptation
Initial Grid: 100 elements
Automation
Grid Generation - GAMBIT CFD Solver - FLUENT
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Grid Generation Automation
GAMBIT saves a “journal” file with the commands issues during a session Journal file are ASCII editable files Commands are quasi-English and easy-to-use They are useful to trace-back sessions to find errors They can be made general by introducing User Defined Parameters
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Optimization Procedure
GAMBIT GAMBIT GAMBIT
PROCESS CONTROLLER
FLUENT FLUENT FLUENT
COST FUNCTION EVALUATION
END
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Optimization Procedure Example
Design and Trim Sails for a Modern Clippper Ship
ME469B/7/GI
By T. Doyle
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Optimization Procedure Example
Design and Trim Sails for a Modern Clipper Ship
With SCHEME you can perform standard operations:
(define my_new_url (+ my_url 0.1))
To interact with Fluent Journal files via parameters it is necessary to use SCHEME commands. Loops and conditional statements
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GAMBIT Journal file
It is possible to perform operations on input parameters
$SUM = $A + 0.5*$B
Several functions are available:
$SUM = SIN($A) $X = INTERSECTING(volume, “volume.5”, “volume.12”)
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FLUENT Example of Scheme file for Adaptation
;;; (custom-field-function/define ,….) … ! Define Adaptation Function ;;; ;;; set few parameters ;;; (define maxcells 200000) …. ! Set Control Parameters (define minref .1) ;;; (do ((j 0) ! Adaptation Loop (i 0 (+ i 1))) ((= i 5) j) (format "\n Iteration ~a step - STARTED " i) ;;; (cx-gui-do cx-activate-item …) … ! Display Adaptation function ;;; (cx-gui-do cx-activate-item "MenuBar*AdaptMenu*Iso-Value...") … ! Adapt ;;; (cx-gui-do cx-activate-item "MenuBar*SolveMenu*Iterate...") … ! Iterate ;;; (format "\n Iteration ~a step - FINISHED \n" i) ) ! End Adaptation Loop
(if (> 3 2) ‘yes ‘no)
See SCHEME reference manual on the Web-site for more information
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FLUENT Batch Execution
Batch NO GUI: Batch with GUI:
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FLUENT Journal Files
Fluent GUI is developed using a LISP dialect called SCHEME To interact with Fluent Journal files via parameters it is necessary to use SCHEME commands. For example to fix the under-relaxation in the momentum equation the command is:
Design and Trim Sails for a Modern Clipper Ship
Optimized Solution for Different Wind Directions
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GAMBIT Journal file
The command:
Volume create width 1 depth 1 height 1 offset 0 0 0 brick
Generates a cube of size 1 centered at 0 0 0 On the other hand the sequence
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GAMBIT Batch Execution
The grid generation process can be performed in batch (without GUI) by using the command
gambit –inp <journalfile.jou>
Batch and GUI execution are EXACTLY equivalent!
$W = 2.3 $D = 1.5 $H = 4 Volume create width $W depth $D height $H offset 0 0 0 brick
Generates a cuboid of User-Specified Size centered at 0 0 0
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Aerodynamic Force Definitions
One cost function is defined as Lift/Drag
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Optimization Procedure Example
Design and Trim Sails for a Modern Clipper Ship
ME469B/7/GI
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CFD Solver Automation
FLUENT can save a “journal” file To start saving File Write Start Journal To stop saving File Write Stop Journal Journal file are ASCII editable files Commands are somewhat “obscure” (keywords, etc.) They can be made general by introducing User Defined Parameters
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Available as adapt.scm from the Website
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Example of Automatic Adaptation
Driven Cavity Problem Start Initial Conditions - Uniform Grid Perform 5 Steps of Adaptation Using Hanging Nodes Adaptation Function is: Scaled Velocity Difference = (Velocity Gradient * Volume1/3)/Velocity
Also Loops and Conditional statements:
if cond ($A .eq. 5) volume create sphere radius ($A+3) endif
See Manuals on the Web-site for more information
ME469B/7/GI
Fl ow
Grid Generation
ME469rocedure Example
Design and Trim Sails for a Modern Clipper Ship