MEEG 681 / MEEG 481
Computer Solution of Engineering Problems
Computer Session 6


Outline and Objectives:
 


 Summary

     GAMBIT (Solver=FIDAP): --> ofepipe.jou, ofepipe.trn, 
                            --> ofepipe.FDNEUT, ofepipe.FIPREP
     Modify ofepipe.FIPREP
     FIDAP: FICONV, FIPREP, CREATE, RUN FISOLV, IDENT, FIPOST
            --> ofepipe.FIJOUR, ofepipe.FIOUT, ofepipe.ps etc.
     Save and modify ofepipe.FIJOUR if needed.


     GAMBIT (Solver=FLUENT 5/6): --> ofepipe.jou, ofepipe.trn,
                                 --> ofepipe.msh
     FLUENT: File-Read, Grid-Check, Define, Solve, FILE - WRITE -Case&Data
            --> ofepipe.cas, ofepipe.dat, etc.


 Where to look for help documentations?

ANSYS5.6 Manuals

Gambit 2.0 Manuals

FIDAP 8.6 Manuals

Fluent 6.1 Manuals
 


More about FLUENT

Here are some useful points about Fluent. This list will be extended as we learn more about FLUENT.

(A) Restarting FLUENT from previous database:
File-Read-Case (or Case & Data)

(B) Where to save your files?
You can save your files on Z: drive. This drive is accessible from both ECALC labs. You should back up your files via SSH File Transfer.

(C) Checking current settings:
Report - Summary - ....



More about FIDAP

The following illustrates some advanced features of FIDAP preprocessing and postprocessing that will let you be more productive in your FIDAP session.
 

(A) Restarting FIDAP session from previous database:
           fidap -id ofepipe -gui -old

 (make sure that there is no file named ``id.FDIDEN''. Otherwise you will get an error
message.  Always remove the file ``id.FDIDEN'' before you restart from database of a previous sesssion).


(B) Important files to save after a FIDAP session:
 

          The journal file:   id.FIJOUR  (This file contains a record of all the FIDAP commands
          executed during a previous session.)

           You should re-name the file:
           mv ofepipe.FIJOUR ofepipe.FDREAD

           You can simply edit the ofepipe.FDREAD file to modify system parameters
               (such as inlet velocity,   viscosity, etc.)
              

           You can also define a variable to be used later on. For example,
                 $VIN=0.5
                  BCNODE(ADD, UY, ENTI = "bottom1", CONS = $VIN, X, Y, Z)

              is identical to:

                  BCNODE(ADD, UY, ENTI = "bottom1", CONS = 0.5, X, Y, Z)
 

(C) Restarting FIDAP session from a modified FDREAD file:

            fidap -id ofepipe -gui -new

            click READFILE, input the READFILE name

            Click ACCEPT will implement all the commands in the FDREAD file
 

(D) Other files created in a FIDAP session:

FDBASE:    This is the FIDAP model database file. This is the database associated with the current problem identifier.

FDPOST: This is the results database file created by the FIDAP solver module FISOLV. This file must be made available for FIPOST to create any plots. By default, it is the FDPOST file associated with the current problem identifier.

FISTAT:   This is the FIDAP status file. All error messages are logged to this file as well as brief summary messages relating to problem setup, CPU times, memory requirements, etc.

 FIOUT :    This is the FIDAP print output file. Detailed information relating to the execution of the various commands is output to this file.

FIECHO: This is the FIDAP input echo file. This file contains an exact record of the commands input by the user.

id.ps:     This is the plot file created by FIPOST when POSTSCRIPT driver is used.


(E) On-line documentations:

You can find all on-line manuals by clicking Help,  and point the question mark on the command window you are working on.  A text window will appear which contains explanations and examples of the command and related options.

(F) Graphical View Options

You can use the View Manu to rotate, translate, and zoom in the graphics.  Or you can use  single letter commands combined with dragging the left mouse buttom to perform the same task:

``GX'' for rotation along x-axis

 ``GY'' for rotation along y-axis

``GZ'' for rotation along z-axis

``1'' for translation in x-direction

``2'' for translation in y-direction

``3'' for translation in z-direction

``T'' for translation in xy-plane

``P'' for zooming in or out

``C'' for zooming in selected region

``E'' for translating a selected point

``M'' for magnifying about a selected point  (press M, click a point in the graphics,
press a magnification number (1 through 9, 9 for maximum magnification)

``U'' for reducing about a selected point (press U, click a point in the graphics, then press a number (1 through 9)

``V'' to restore the previous view

``D'' to redraw the graphics

``F'' to fill the graphics to the entire window

``H'' to produce a hard copy


(G) Checking the database before running the solver:
 

For a big problem, do

FIPREP-Simulation-EXECUTION MODE=DATACHECK
RUN-FISOLV

to make sure you do not get any errors in the FDSTAT file.


(H) FIPOST Capabilities

FIPOST is a command-driven program which is directed to perform various task by entering commands. These commands fall into a number of different categories based on their function. Following is a partial list of important FIPOST commands grouped according to their function.

Plot Commands

Each of the Plot commands results in the display of a particular type of plot.

CONTOUR:  generalized contour plot command for contouring both solution fields and derived variables, including turbulent dissipation, turbulent kinetic energy, pressure, stream function, temperature and vorticity amongst many others

CONVERGENCE: plot convergence history of the simulation

EDGE: edge plot of model (optional display of initial and/or boundary conditions)

HISTORY:  time history plot of solution and derived variables

LINE:  plot of any solution or derived variable along any line in space

MESH: element mesh plot

PARTICLE: define particle injection points for PATH command

PATH: particle path and dye trace plot

SEARCH:  graphically query values of solution or derived values

STEP: time history plot of time increment in a transient analysis

VECTOR:  vector plot of a solution variable, including velocity, vorticity and stress

XYPLOT :  user defined x-y coordinate plot


Computation Commands
 
Computation commands result in the computation and printout, as well as optional plotting, of various quantities derived from the solution variables.

COEFFICIENT:  compute heat or mass transfer coefficient at any element boundary

FLOWRATE: compute flow rate across any element boundary

FLUX:  compute heat fluxes across any element boundary

MEAN: compute the mean of a solution quantity

PROPERTY:  compute nodal property values

STRSPRINT:  compute stresses at any element boundary

YPLUS: compute turbulent y+ values at any element wall boundary


Display Commands
 

Display commands manipulate the graphics image to be displayed on the plot.

DISPLAY :  select the view direction and angle for display of an image

GCPOINT:  define the graphics control point

GROUP:  restrict plotting to selected element groups

PLANE: specify a cutting plane and active display surface for 3-D plots

RESET: reset all viewport, window and display parameters to their default values

SETWINDOW: set windows to which subsequent commands apply

TRANSFORM: compute a new variable for plotting by applying a transformation to a specified solution or derived variable

VIEWPORT:  select the area of the graphics device to be used to display the plot

WINDOW: controls all operations relating to the creation and modification of graphics windows in FIDAP

ZOOM: select the portion of the model to be displayed on the screen (using dimensionless screen units)
 

Graphics Options Commands
 
Graphics Options commands enable or disable various optional features
available for the plot commands.

AXES:   enable or disable plotting of axes on plots

BOUNDARY:  select type of boundary to be drawn surrounding the model

COLOR :  enable or disable color plotting

GRID:  select background mesh plotting on contour plots

HEADING:  select type of titling information to be displayed

PATTERN:  specify options for use of color on vector and contour plots

SETCOLOR: set or modify color tables

SUPERIMPOSE:  enable or disable superimposing of plots

XYSET: set options for x-y coordinate plots


Utility Commands
Utility commands perform various miscellaneous functions.

DEVICE : select the device driver for graphics output

ECHO: control amount of information echoed to the screen

NEUTRAL: output solution data to a neutral file

OPTIONS: set various program options

PRINT : print out solution variables

SCALE: scale solution variables

TIMESTEP: select a time step from the results database file

TITLE:  enter new titling information for plots
 

(I) FDPOST examples:

A simple plot:

PLOT-Line-Degree of Freedom=shear-Line definition: Entity="right"-Accept
Adding a title:
TITLE-SET PLOT TITLE-shear rate along vertical wall-ACCEPT
Customize vertical axis label:
Utility-XYSET-Y axis minium=0-Y axis maximum=0.06-ACCEPT
Save data to a file:
Utility-Neutral-FILE FORMAT=FIPOST-Degree of Freedom=Shear-FILE name="shear.out"-ACCEPT
Changing Display Colors:
GRAPHICS-SETCOLOR-SETCOLOR OPTION=EDITOR, GENERAL COLOR=3, BACKGROUND=2 (white), ETC ........ (Make sure to open new window for the new color map to take effect (use Graphics-Window-Open)
Checking BC's:
EDGE-PLOTTED INFORMATION=BCNODE-NODAL D.O.F.=Velocity-ADD-Accept


Multiple display windows (display four plots simultaneously):   Example

WINDOW-WINDOW ACTION=4SPLIT

SETWINDOW-DELETE-ALL
(All window will be inactive.)

SETWINDOW-ADD-WINDOW=2
(only window 2 will be active.  See FIDAP command history window for such information.)

EDGE-PLOTTED INFORMATION=BCNODE-NODAL D.O.F.=Velocity-ADD-Accept

SETWINDOW-ADD-WINDOW=3
(only window 3 will be active. )

MESH-ACCEPT

SETWINDOW-ADD-WINDOW=4
(only window 4 will be active. )

VECTOR-PLOT TYPE=VELOCITY-ACCEPT

SETWINDOW-ADD-WINDOW=5
(only window 5 will be active. )

CONTOUR-DEGREE OF FREEDOM=Streamline-CONTOUR LEVELS: AUTOMATIC=40-ACCEPT


(J) Color Display Problem

You may experience graphic display problem if the colormap on your host does not match what FIDAP uses as default.  FIDAP uses 256 colormap.  Therefore, make sure that, on your PC, you check the DISPLAY-SETTINGS.  Change to 256 colors if necessary.  You will have to restart Exceed and FIDAP
after you change your host display settings.