User Primer for SINGS programs


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Note:
It is strongly suggested that you first set your mouse cursor
to auto-focus, meaning that you don't have to click on a window
in order to type into it.  On Athena, follow the pulldown menus:

Menu
  Settings
     Gnome Control Center
        Windows
           set cursor to auto-focus  (terms varies with Window Managers)

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Sample SINGS session is below.

Commands are shown capitalized, but are not case-sensitive.

Blank lines below are for clarity.  They are NOT Enters!

Indendation indicates menu level.

A command in quotes, e.g "+", means that the character
is typed when the cursor is in the plot window rather
than the text window.

Most commands want numerical arguments.
Prompts will be given for omitted arguments.
Default argument values are always given in brackets,
and can be accepted simply by hitting <Enter>.


Start SINGS.

  On Athena Linux boxes (NOT available on the Suns):
    % add 16_d0006     (suggestion: put this command in your .cshrc.mine file)
    % singsexec

  On your Linux system with downloaded executable and libraries (see linux_install.txt):
    % sings


For easiest typing and viewing, it is suggested that you move
the text window to the lower-left corner of the screen, and
then move the graphics window to the upper-left or upper-right 
corner of the screen.


SINGS commands, with comments added:

?        display command menu

A        go to add/edit flowfield submenu
  F           add freestream (no arguments will generate prompts...)
     1           specify V_inf = 1.0
    <Enter>      accept default freestream flow angle (0.0 in this case)
  S  2 -1 0   add source of strength Lambda = +2 ,  at x = -1 , y = 0
  S -2  1 0   add  sink  of strength Lambda = -2 ,  at x = +1 , y = 0
  <Enter>     exit add/edit submenu, go back to main menu

V        go to velocity sensor add/edit menu
  P  0   0.7    place sensor at x = 0.0 , y = 0.7
  P -1.2 0.4
  <Enter>     exit sensor add/edit submenu, go back to main menu


K        enter keystroke-modification submenu

     place cursor in graphics window, closest to singularity to be modified, 
     then issue keystroke commands (hold down for repeated action):

  "rightarrow"   move right
  "rightarrow"   move right
  "rightarrow"   move right  (can hold down)

  "leftarrow"    move left, etc

  "+"            make strength more positive
  "+"            make strength more positive

  "-"            make strength more negative

  "0"            set strength to 0.0
  "1"            set strength to 1.0

  "s"            change sign of strength

  ">"            rotate clockwise (this has no effect on sources or vortices)
  "<"            rotate counterclockwise

        place cursor outside of plot grid to target the freestream for commands

  "/"            select sensor editing
  "rightarrow"   move sensor right
  "+"            increase sensor scaling factor

  "space"        exit keystroke menu


T        enter contour (isoline) selection submenu
  P        toggle isopotential plotting ON
  P        toggle isopotential plotting OFF
  V        toggle isovel plotting ON   (isovels are equivalent to isobars, via Bernoulli)
  <Enter>  exit add/edit menu, go back to main menu

         the colors now indicate velocity magnitude in the flowfield.
         if the dividing streamline represents a solid oval body, then only
         the isovels outside the body are physically significant.

D        set isoline delta values
   10       set dPsi = 10
  <Enter>   leave dPhi unchanged (default value)
  <Enter>   leave dVel unchanged (default value)
  <Enter>   leave dCp  unchanged (default value)

         the large dPsi = 10 increment will result in only the Psi = 0 isoline plotted.
         for this case, Psi = 0 corresponds to the dividing streamline.

C           change isoline coloring
   V 0 2    set isoVel coloring from 0.0 to 2.0, to get more resolution closer to V=0.
   <Enter>

H        write current plot to plot.ps file

A        go to add/edit flowfield submenu
  -3          delete the sink (item 3)

   2          change the source
     <Enter>      keep current source strength
      0           change x location to 0.0
      0           change y location to 0.0

   D          add doublet
      6.28      strength of 2 pi
     <Enter>    at x = 0.0
     <Enter>    at y = 0.0
     <Enter>    with zero axis angle

   V          add vortex
      4         strength of 4
     <Enter>    at x = 0.0
     <Enter>    at y = 0.0

  -2          delete the source

   <Enter>

M           change contour (isoline) levels to skip huge velocities near doublet
   <Enter>     don't change min Psi  
   <Enter>     don't change max Psi  
   <Enter>     don't change min Phi
   <Enter>     don't change max Phi
    0          set min Vel = 0.0
    5          set max Vel = 5.0
   <Enter>     don't change min Cp
   <Enter>     don't change max Cp

H        append current plot to plot.ps file

Q        quit SINGS  (necessary to properly close plot.ps file)