Free!Ship 2.6+ vs Prediction resistance by Holtrop-Mennen started method

Discussion in 'Software' started by Victor T, Feb 16, 2007.

  1. apex1

    apex1 Guest

    :D :D :D ja, Steve:D :D :D
     
  2. JohnnyC
    Joined: Mar 2007
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    Location: Tennessee, USA

    JohnnyC New Member

    Victor T.. Thanks for a great looking application.

    I have read/searched this site for a few years. Thanks to all who have added to my knowledge. This is by far the best site with the greatest collection of talented people who are (most times) freely willing to share "some" knowledge.

    To all who replied: Sorry, I couldn't open the software that wouldn't work to tell you version number. LOL... Never a dumb question, right? The links I was hitting from Victor's posts only lead me to one version. I forget which. I have downloaded 3.01 and have it up and running. Looks really nice as I'm trying to understand it and my potential uses.
     
  3. JohnnyC
    Joined: Mar 2007
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    JohnnyC New Member

    I am a mechanical engineer/manufacturing engineer of 30+ years and have been using AutoCAD Mechanical Desktop and AutoDESK Inventor for many years in the manufacturing industry. Solid modeling and developable surfacing has unmatched accuracy in AutoCAD in my opinion. I use variables in my parametrics and I link these to Excell spreadsheet formulas to automatically calculate "simple" coefficients and weight schedules. Other calculations such as center of bouyancy, Metacentric height and Center of Gravity are simple for me to obtain as well.

    I am looking at this Free!ship+ software to see what I can add to my understanding and evaluation of hull shapes. Like others with machining/manufacturing/welding skills, I will build my own aluminum boat/yacht. I'm 2 years (very part-time) into the design spiral of a trailerable boat for inland waterway, week-long getaways. I'm not sure I would even attempt it without this site. Long, narrow, efficient, dependable, safe, 75 h.p. diesel with a range around 500 miles or so are a few of my goals.
     
  4. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Hi JohnnyC, welcome aboard :)

    I think you'll find, as many of us have, that the Freeship software, in its various forms, is a very quick way to get the initial hull shape you want. Things like the curve of areas, the linesplan, all the important coefficients of form are all readily accessible. It is, however, not ideal for detailed structure and construction drawings, and is best used in conjunction with a bit of conventional CAD software.

    Several of us, myself included, have built or are working on projects similar to yours. Do feel free to start a thread on here to discuss your planned design; a lot of members are interested in boats like this and will be very helpful in informing your design goals and approaches.
     
  5. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    JohnnyC, I've sent you an email.
     
  6. csarmvs
    Joined: Jun 2009
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    csarmvs ing. naval

    finally was always in my face

    haha .. I just discover how move all my designs to freeship + .. through
    VRML files!! hahahaha .. sometimes I feel very dumb haha
    :p :D , well I hope this will be usefull to someone else
    regards
    cesar
     
  7. Victor T
    Joined: Feb 2007
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    Victor T Senior Member

    Test only Version 3.08+
    Date: September 30, 2009
    New features:
    * Added import interaction coefficients (Wt and t) in propeller tasks from resistance calcs
    * Added 4 types of ships in aerodynamics characteristics calculation
    * Added graphics output results by Savitsky method calculation
    * Added trim angle for planing ships in graphs
    * Changed output data results format in 8 tasks (for report's print)
    * Fixed bug in stability calcs
    * Added 5 new multilanguage messages
    * It's made more than 40 little changes and corrections for interface

    Regards
     
  8. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Hey Victor,
    September 30 was my birthday, thank you very much for a great gift! :)
    You did an excellent job, as always.
    Cheers!
     
  9. apex1

    apex1 Guest

    Hmm, may I cue for thanks? Mine was on 1. of Oct. so I still can see that as a gift too?

    Richard
     
  10. Victor T
    Joined: Feb 2007
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    Location: Ukraine

    Victor T Senior Member

    Hi!

    Release version Free!ship Plus 3.1+ with source code is available now.

    Regards
     
  11. masrapido
    Joined: May 2005
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    masrapido Junior forever

    Not one of them, but FS+ works just fine in Vista.
     
  12. masrapido
    Joined: May 2005
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    Location: Chile

    masrapido Junior forever

    Also, I've discovered that if I add the step to the hull, like the step on hydroplane's pontoons, the calculations go beserk. CoG, total weight, angle of entry, ust to name a few, they all go their own separate ways.

    The Layers info and the Calculations - Design Hydrostatics results will show different numbers for the same hull.
     
  13. capt vimes
    Joined: Apr 2009
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    capt vimes Senior Member

    victor
    there is a small bug or mistake in the hydrostatics calculation...
    the CP (prismatic coefficent) is calculated for the canoe body only but the software takes an added keel into account as well which is not correct...
    resulting in a too low CP and therefore restistance calculation (kaper) might not work anymore stating that the CP is out of range...

    if i am mistaken regarding the CP calculation please disregard this post but to my knowledge and information the keelarea should not be part of CP computation...
     
  14. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Whether or not to include a keel in the Cp calculation is a matter of some debate. Common practice is to exclude a deep fin, but to include an integrated or long keel. For shapes in between, it's very much dependent on what the designer is used to and how the boats he's comparing it to were measured.

    The distinction is generally at the designer's discretion, based on his experience with how previous boats performed. It is probably better to be able to make the distinction yourself (turn off the "use for hydrostatics" property on the layer containing the keel) than to try to come up with an algorithm by which the software will decide where the hull ends and the keel begins.
     
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  15. capt vimes
    Joined: Apr 2009
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    capt vimes Senior Member

    thank's matt

    i know that long or integrated keels should be considered when calculating the CP but not fin keels...
    every single graph or comparison i have at hand is for fin keels only and nowhere the keel is taken into account for the CP...

    to uncheck the "use for hydrostatics" is not a good option for my liking since you want to have it for CG and dynamic stability calcs...
    wouldn't it be better to include a checkbox "fin keel" or something similar and if checked the keel will just be neglected for CP calcs... ?

    i think that that is also pretty easy to program and no need to have complicated algorithms and stuff...
     
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