X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: fd588,953ba2645a1b110,start
X-Google-Attributes: gidfd588,public
From: schoon@na.chalmers.se (Johannes Schoon)
Subject: [announcement] preliminary results from cheapflaw
Date: 1997/09/24
Message-ID: <60bbrh$l11$1@nyheter.chalmers.se>
X-Deja-AN: 275302510
Organization: Chalmers University of Technology
Reply-To: schoon@na.chalmers.se
Newsgroups: alt.ascii-art.animation


Hi again,

I'm working hard at CHEAPFLAW, possibly the silliest fluid flow
simulation program ever conceived. It is not quite ready for a public
release, but I thought you would be interested in what it's all about.

Input can look like this:

#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                   
#oooooooooooooooooooooooooo                                .  
#oooooooooooooooooooooooooo                              . . .
#oooooooooooooooooooooooooo                             . .  .
#oooooooooooooooooooooooooo                             . . . 
#oooooooooooooooooooooooooo                             ..    
#oooooooooooooooooooooooooo                          # #      
#oooooooooooooooooooooooooo                         ####      
#oooooooooooooooooooooooooo                        #####      
#oooooooooooooooooooooooooo                       ### ###     
#oooooooooooooooooooooooooo                        #####      
#oooooooooooooooooooooooooo                        ## ##      
############################################################  
                                                              

This is my version of the classical free-surface test-case "bursting
dam". The house is added for the dramatic effect. The idea is that the
"water", when released, will rush to the right, hit the house, and
make a big splash. When cheapflaw is set off with this input, it
starts to pump ascii-graphics snapshots to standard output. In real
time. 

As the code is right now, it will look like this after a while:
 
#                                               .                   o  
#                                                                   o  
#                                                                   o  
#                                          .                        o  
#                                                                      
#                                                                   oo 
#                                                          .         o 
#                                                                      
#                           o                                          
#        o                                             .   ..          
#         o  oooooooooooooo  oo                                        
#         oooooooooooooooooooo o                                       
#         oooooooooooooooooooo ooo                   # #   .           
#         oooooooooooooooo ooo ooo                  ####               
#         oooooooooooooooo ooo ooo                 #####               
#    o    oooooooooooooooo ooo ooo    .           ### ###             o
#       o oooooooooooooo ooooo ooo                 #####               
#   o o  oooooooooooooo  oooooooo                  ## ##             oo
############################################################        o  
     oo  ooooooooooooooooooooo ooo                                  o  
          o  oo        o ooo ooo                                    o  
         ooooooooooooooo o   o oo            .                      o  
                        o   o                                       o  
                                                                    o


Obviously, something is seriously wrong with my physics. Not only does
the fluid escape through the "ground" barrier, it fails to squeeze out
at the bottom. (BTW, I use a standard arcade game torus topology, so
the fluid at the far right has actually escaped through the wall at
the left.)

And it only gets worse. By time-step 27 it looks like this:


          o                      o                            o    
               oo   oo o ooo        o o    .                  o    
              o   o o  o   o ooo oooo o o                     o    
#                  o    oo oooooooo o o  o               .         
#                     oooooooooooooo .ooo o                        
#      o    ooo oooooooooooooooooooooo o oooo                      
#        ooooo   o o ooooooo    oo o  .   ooo                   o  
#           o    oo   oooooooo  o oooooo   ooo                  o  
#                  oo    ooooo o  oo o o  o  o                     
#               o       o  o oo      oo                 .          
#               oo   o   o oo     o  o                             
#                      o     o                            o        
#o             o                     o                  .          
#    o             .                        .         . .          
#  o                                                        o    o 
#    o               o        o                      # #           
# o               o                                 ####           
#  ooo o               oo                          #####  .        
# o   oo  o o    o            o     o   o         ### ###      oo o
#       oo o o     o o    ooo o     oo oo          #####      o   o
# o         oo oo   o  o o ooooo o o o o oo        ## ##      o    
############################################################  o    
                 oo   oooo       o    oo  o                   o    
                         o      oooo o                              


Most of the fluid has now penetrated the ground, and is now
falling down like some super-dense cloud. Everything more and more 
chaotic, and by time-step 50 there is no structure left at all:	   
								   
								   
  oo                              o      o         o    o  o  o o  
o.     .          o                         o.oooo  ooo      oo  o 
         o ooo            . o       o           o o   ooo     o    
#      oo  oo o  o o  o            o    o o    oo o o  oo    o   o 
#  oo  o   o   o o        o   o  o        o oo     o     o  oo o  o
#o o      o  o o     o ooo  o      o      oo  o   o   oo o  o      
#o      o  oo   o   o    o   o       o o    o      oo oo o         
#     o     ooo o  o oo oo         o   o     o   o o   o    o      
#         o  o  o   o o   ooooo    .  o   oo o   o        oo o o   
# o              o    o o  o o      o  .            o    o o       
# oo    o             ooo                   o  o o oo   o o  o     
#          o    ooo  ooo           o o o    o o      o   oo   oo   
#   o  o    o    oo        o   o  o oo         oo oo o  o o     o  
# o         o                      o o o         oo o  oo          
#                    o         .    o           o      o      o o  
#o  oo      o            o          o        o     oo# o o         
#      o           o    o     o   oo o oo o       o ####o          
#o   o      o                          .o  oo     o##### o   oo ooo
# o    o    o           o   o   o oo     .       o###.###   o      
#o   o o           o            oo    o   o     oo ###o#    o  o  o
#         o      o        o    o   o     o       oo## ##   o       
############################################################     o 
 ooo o   o  o    o     o    o   o     o oo             o           
   o       o  o   o       o      o    o   o  o   o  o   o          


I hope you enjoyed this, I'll be back when things look more
promising. Right now I have some problems making my free-flying solid
bodies keep their shape.


Yours

Johannes Schoeoen

"master of research under the event horizon"
(No matter how much work you throw in, nothing ever comes out.)
dept. of Naval Architecture and Ocean Engineering
Chalmers University of Technology, Gothenburg, Sweden

p.s. Whether I can keep the name CHEAPFLAW on my code depends on what
my friends at Flowtech International AB think about it. The name is
quite similar to SHIPFLOW, the code marketed by them.