1D Lagrangian Hydrocode V5.2

Polymorphic material types, strength, detonics, spall (Ariadne V6.1)

Operation

Here we assume that the system has been configured so that the programs can be run by typing their names, without a path. If you need to carry out a large set of calculations which are reasonably similar, then it is usually easier to set up a shell script or batch file to perform steps automatically, choosing some convention for file names. Example shell scripts are shown below.

The detailed set of steps is as follows:

  1. Use the problem generator to set up a discretised description of the problem. This will be normally be a separate file.

    It's advisable to store the generator input in a file as well. If this is called say gen.in, and if it contains comments (lines or ends of lines starting with #), then the generator would be run with a command like 

       expandec < gen.in | lag_gen1d.x > gen.out
  2. Remove comments from the input to the main program, and add the geometry data. If the input to main program has been configured to use the expandec program, the name of the generator output file can be referred to by a line like 
       ++gen.out
    at the appropriate place in the data.

    The input for the main program can then be set up with a command like 

       expandec < pc.dat | xpan > pc.in
    (assuming the basic data for the main program is stored in commented form in a file pc.dat).
  3. Run the main hydro predictor-corrector time integration: 
       lag_pc1d.x < pc.in > pc.out
    or just 
       lag_pc1d.x < pc.in
    if you want to watch the time step info scroll past. (Some terminal programs abort if too much text comes through too quickly, so if this happens then try saving it in pc.out and looking later.
  4. Look at the hydro output. The format is designed to be compatible with common graphics programs such as Gnuplot. It should also be suitable for reading into most spreadsheets, with minor editing. The example Gnuplot input files below can be used to generate Postscript graphs, with a command like 
       gnuplot stube.gp > stube.eps
    Apart from the commands which specify Postscript output, the other commands can be edited at the Gnuplot command line to generate on-line graphics if your terminal is set up to display them. Example: 
       gnuplot
   > set xlabel "position"
   > set ylabel "pressure"
   > set data style lines
   > plot "PLOT000" using 1:8 title "t = 0.1", \
           "PLOT001" using 1:8 title "t = 0.2", \
           "PLOT002" using 1:8 title "t = 0.3", \
           "PLOT003" using 1:8 title "t = 0.4"
    (See the Gnuplot manual for abbreviations, other options etc.)

Files

(In all cases, material or geometry data should be inlined where indicated, e.g. using expandec.)