ULIMICH version 1.0

Discussion in 'Software' started by Leo Lazauskas, Sep 2, 2012.

  1. Leo Lazauskas
    Joined: Jan 2002
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    Leo Lazauskas Senior Member

    ULIMICH v 1.0
    =============
    Ulimich calculates Michell's integral for a monohull.
    It runs under Windows and DOS on most modern PCs.
    The executable file is "ulimich.exe".

    The program reads a plain text file named "ulimich.in" and outputs the
    wave resistance to a file named "ulimich.out". There is no screen
    output, unless you have made a mess of the input file and some error
    messages appear.

    The program is very unforgiving: there is no error checking. Don't put
    spaces between lines!

    The first 7 parameters in the input file are:
    gravitational acceleration (m/sec/sec)
    water density (kg/m^3)
    Ship speed (m/sec)
    LWL (m)
    Draft (m)
    Number of stations: odd integer 5 <= nx <= 41.
    Number of waterlines: odd integer 5 <= nz <= 41.

    A table of offsets must be specified immediately after the first 7
    parameters. The format is the same as a Michlet offset table with one
    very important difference, namely, there must be a comma at the end of
    each line.

    To uninstall the program, just delete the subdirectory containing the
    executable.

    EXAMPLES
    ========
    To run the examples, you must rename the example file to "ulimich.in"
    and then run the executable.

    "wigley21x21.in"
    ----------------
    Model-sized Wigley hull with 21 stations and 21 waterlines, similar to
    the Wigley example in Michlet. This is the same as the "ulimich.in"
    file when you first unzip the file you downloaded.

    Results can be compared with those produced by Michlet, but remember
    to use a negative value of Ntheta to prevent Michlet including the
    boundary layer before calculating wave resistance. Also note that
    Michlet outputs Rw in kilo Newtons; Ulimich's Rw is in Newtons.

    At 3.0 m/sec, I get:
    Michlet: 27.5307 Newtons
    Ulimich: 27.5018 Newtons

    The small differences are due to accuracy of the integrations. Ulimich
    is faster, but very slightly less accurate.

    "m1x41x33.in"
    ----------------
    Single rowing shell, similar to the m1x.mlt example in Michlet.

    At 4.0 m/sec I get:
    Michlet: 3.20807 Newtons
    Ulimich: 3.20478 Newtons

    =================== END OF INSTRUCTIONS =================
     

    Attached Files:

    1 person likes this.
  2. baeckmo
    Joined: Jun 2009
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    baeckmo Hydrodynamics

    Ooh, beautiful, no nonsense, just data in and data out; I like that!

    Thank you Leo!!
     
  3. CWTeebs
    Joined: Apr 2011
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    CWTeebs AnomalyGenerator

    Thank you Leo.
     
  4. Leo Lazauskas
    Joined: Jan 2002
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    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

    I could make a Windows version, with little purple curlicues in the corners and
    a thematic colour scheme, but it would be 2 Mb instead of about 30kb :)
     
  5. quequen
    Joined: Jul 2009
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    quequen Senior Member

    Thanks Leo!
    Is it compatible with Delftship or Freeship michlet output files?
    edit: no, but could be with some text edition I guess...
     
  6. Leo Lazauskas
    Joined: Jan 2002
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    Leo Lazauskas Senior Member

    The offset table is exactly the same, except you must add commas at the end
    of each line. (Unfortunately, Fortran 77 is not very good at reading some
    formats.)
     
  7. Remmlinger
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    Remmlinger engineer

    Leo, do I need to feel flattered now?
    I have not yet managed it to link it to my FORTRAN program
    Uli
     
  8. Leo Lazauskas
    Joined: Jan 2002
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    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

    I needed a name quickly for this simple program which dozens of others have asked me to release over the last year. You gave us the results of your
    research, I got an idea for a name, and it's now off my list of things to do.
     
  9. Remmlinger
    Joined: Jan 2011
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    Location: Germany

    Remmlinger engineer

    My first step to immortality;)!
    Uli
     
  10. Leo Lazauskas
    Joined: Jan 2002
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    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

    Mind the last step!
     
  11. CWTeebs
    Joined: Apr 2011
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    Location: Maine

    CWTeebs AnomalyGenerator

    So just to check to see if I understand, the output in the *.out file is the steady wave making drag?
     

  12. Leo Lazauskas
    Joined: Jan 2002
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    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

    Yes it is. Rw is Newtons, not kilo Newtons as in Michlet.

    Wave resistance is just Michell's integral.

    I'll try to release a short program in the next few days that calculates wave
    resistance given a longitudinal wave cut or series of cuts.
    That won't be restricted to thin ships.
    In fact, it should work for beamy monohulls, ACV, SES, yawed ACV etc.
     
    Last edited: Sep 7, 2012
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