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

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

  1. Victor T
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    Victor T Senior Member

    If you create inside layers or tanks in the hull that it is necessary to disconnect their account in project hydrostatics as they shouldn't create force of buoyancy (Archimedes force)
     
  2. Victor T
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    Victor T Senior Member

    It is very interesting information. But Delphi 7 compiles a code only for 32 bit OS. I don't check compatibility with 64 bit systems and Linux.
    But on a site www.x64bitdownload.com it is informed on compatibility with 64 bit OS Windows 64.
    See here: http://www.x64bitdownload.com/downloads/t-64-bit-freeship-plus-download-kxeryrsz.html
     
  3. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    I to my surprise and uncontrolled excitement last night serendipitously used a sealed, 4-pointed cylinder and added points and reshaped and constrained it to the confines of the bulkheads, centerline, and sideshell. When i turned on the hydros, it did not pig-tail the SAC. Upon closer inspection, i realized that by pure chance, my tank boundaries were at least (or something like) 20mm from the fore/aft boundaries of a given compartment/mesh of the compartment.

    When I copied (by way of exporting and renaming and reimporting the part of) the tank and transformed its distance, the SAC changed, but then that was because it had situated too close to the station forming the fwd bdry. So, I moved it and WHALLA! The SAC returned to normal.

    However, in the case of the first tank, flipping the normals has a noticable effect on the KM and displacement. One of the transformed tans fwd of amidships has a very minor effect. It still is a lot of work, but I'm okay with that since I can export the meshes and then in ViaCAD Pro, convert the meshes to surfaces, stitch them, assign them the material of "JP-5" and then get my tank weights. It would be nice if FS/DS directly calculated volume, but ViaCAD gives me the volume. Using meters as units, I can readily knock of 3 decimal places and get my tonnage in metric, and quickly decide how many more tanks I need. Currently, I'm aiming for 2,200 metric tons for JP-5, with the upper tank top or boundary at 4 meters, so it is below my DWL and also below the working decks.

    Once I finalize my tank shapes and number and locations, I then can put them on a BOM (Bill of Materials) and export that to my spreadsheet where I'm tracking CGs for everything from stringers, girders, long'ls, and more, even the bulkheads. Later I'll cut the solid plates and insert facsimilis for watertight doors, scuttles, hatches, safety line stanchions, pillars, in-passageway transformers, the Gas Turbine and Reduction Gear foundations and so on.

    Soooo much fun here, Victor!
     
  4. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    The perils of upgrading (willingly or by coercion, hehehe) to 64-bit...

    If I give up on Fung, is it safe to assume that my Holtrop calculation results are (for fictional purposes, tempered by reality) are reasonably good as far as the tactical turns, stability, and powering and resistance calcs go? I'm pleased that Holtrop works fully (reports and graphic chart), but I suppose that I can live without Fung if it's not more than 10% different that Holtrop...
     
  5. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    Thanks, but I got this:

    http://www.hydro.nuos.edu.ua/downloads/FreeShip3_07 update.rar

    "The connection was reset

    The connection to the server was reset while the page was loading."
    by desktop and

    "Web page not available

    The Web page at http://www.hydro.nuos.edu.ua/downloads/FreeShip3_07 update.rar might be temporarily down or it may have moved permanently to a new address."

    I searched for it using:

    FreeShip3_07+update.rar

    but I'm not sure of those sites and am on a work computer...

    I'll have to try later...
     
  6. Victor T
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    Victor T Senior Member

    This is very old link and site www.hydro.nuos.edu.ua is not available now (intranet only). And Fung-Leibman method was added to 3.13+ and higher...
     
  7. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    Thanks!

    I still checked, though, on a weak assumption that there might have been a different code base.

    Cheers!
     
  8. daiquiri
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    daiquiri Engineering and Design

    For what it's worth, I have never ever managed to make Fung calculation work (always get the error message about slow PC or something) even for hulls with parameters which should be ok for Fung method. I am running the FS in Win XP. At this point I suspect there is something wrong in the exe file.
    Cheers
     
  9. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    Same here. I hope somebody fixes it, at least so there's a "Fung-Trop", hehehe....

    But, I am hoping that the working Holtrop method and sea ships method are reasonably close or not glaringly out of comparison. It's not as if hobbyists knowing these things brings peril to real navies. In 1970, this would be somethng to worry about. Nowadays, overcompensating software can makeup for lack of information, at least at the State-level.

    Funny thing about the Fung exe is that most of the data is there minus the chart.

    What I am suspecting, though, is that (other than just being very busy with work/school) Victor probably had to disable or cripple it or leave it as it is, or maybe there is a hostile/litigous competitor out there, or the various governments or navies just are peeved and are activly causing it to "vanish" ro behave badly. DFARS and other things the USA imposes most likely DO have something at the military level to say about it, however antiquated missileers may make some things.

    OTOH, so much exciting (and a lot of dry but necessary-to-be-studied) stuff is learned and available to Nav Arch students in the desire for States to cling to their domestic naval and commercial shipbuilding and operating programs that they have really little choice: recruiting and retaining qualified, motivated, commited, creative thinkers and designers is hard in the USA. A precipitous drop. Some of the various documents afloat in the Internet(s) have some excoriating things to say about failures on the part of the USA (some preventable, some inevitable due to the rise of Japan, South Korea, Vietnam, and China, to just speak of modernized Asian locales, and due to ruthless, intense, laser-like focus on keeping or growing their markets through awe-inspiring efficiencies, cross-training, reduce union roles, and more. Sobering reading material.

    Eventually, somebody will make some of the software more flexible and up to date. Imagine D&D (Dungeons & Dragons) or Trek-like fans who are programmers deciding to make online combat sims that rival the Longbow Apache games and others. Who'd play a game in which a ship has an implausibly constant turning circle lacking advance and transfer. Even ex-naval players will be excited if hydros behave according to physics and not according to a state imposition tha the waves respect classification markings... hehehehe
     
  10. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    Well Well,

    There is a 3.23 Test version for Freeship at hydronship.

    http://hydronship.net/index.php?lang=en

    Been available since July 6. It is not the full version, apparently, since it is about 3.7 mb. But, maybe it'll do calcs if you put the requisite folders in the app's path.

    I'm going to take it or a whirl tonight.
     

  11. CmbtntDzgnr
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    CmbtntDzgnr Senior Member

    Hmmmm... I thought that I had posted that 3.24 is available and that Fung-Leibman works for naval ships.

    Now, the funny thing is is that when I look at historical information, USN ships hydros are checked using Holtrop.

    I therefore went to using both, but the differences can be large.

    On my cruiser hull, I see entrance angles of 82 degrees. I experimented, trying to push in control points to adjust the flare and beam of the hull at the waterline for the first maybe 20 meters. I cannot appreciably decrease the entrance angle.

    But, when I scaled up by 1.3 x the Type-23 hull for length and draft... 1.25x for the beam, i found a somewhat better entrance angle in Fung-Leibman. But, in Holtrop, the entrance angle was better. But, not for my ship model.
     
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