use of POLYCAD naval design software

Discussion in 'Software' started by JFD, Jan 30, 2020.

  1. sujeethmonu
    Joined: Jan 2013
    Posts: 29
    Likes: 0, Points: 1, Legacy Rep: 3
    Location: india

    sujeethmonu Asst Professor(mech dept)

    Even with this calculations in kg and metres, the values are wrong.
    Check this hydrostatic calculation from the file which you sent me with (unit in m), only thing is I have enabled WPA(m2)=water plane area.
    error in polycad.PNG
    at T=0.15m, WPA=2.28m2 and Tonnes per Centimeter Immersion (TPC) = (water density of sea water in tonne * WPA in m2) /100 (in tonne/cm)
    so TPC should be = 1.025 tonne/m3 * 2.28 m2 = 2.34 tonne/m since it is not divided by 100.
    TPC value is correct but unit should have been tonne/m or it should be 2340kg/m.

    so if boat is added with mass of 2340 kg, it will sink deeper in water by 1m.
    for 0.025m increment in draught (as shown in calculation table), it will sink by 2340*0.025=58.5kg

    At 0.15m draught, disp(kg)=223.876kg
    At 0.175 draught, disp(kg)=223.876+58.5=282.376 which is apprx to 283.315kg as shown in calc table.
     
  2. pafurijaz
    Joined: Dec 2016
    Posts: 152
    Likes: 22, Points: 28, Legacy Rep: 18
    Location: Italy

    pafurijaz Senior Member

    But I think you use a wrong draughts input of values.
    this is the correct input for draughts that I usually input in the filed for this variable
    every value is separated by ";" and the "," is for decimals without "()"

    That is the way, and the values are progressive.
    0,15; 0,25; 0,3
    or in your case with dot as separator for decimal.
    0.15; 0.25; 0.3
    Try this type of input
     
  3. sujeethmonu
    Joined: Jan 2013
    Posts: 29
    Likes: 0, Points: 1, Legacy Rep: 3
    Location: india

    sujeethmonu Asst Professor(mech dept)

    got it. (0.15, 0.3, 0.025) working as well. (starting draught, end draught, increment draught)
     
  4. sujeethmonu
    Joined: Jan 2013
    Posts: 29
    Likes: 0, Points: 1, Legacy Rep: 3
    Location: india

    sujeethmonu Asst Professor(mech dept)

    I just mentioned that TPC value being calculated in polycad is wrong.
     
  5. pafurijaz
    Joined: Dec 2016
    Posts: 152
    Likes: 22, Points: 28, Legacy Rep: 18
    Location: Italy

    pafurijaz Senior Member

    OK, fine. I hope you can solve that with the developer, in these days I'm a bit busy, with a work and I'm bit late..
     

  6. sujeethmonu
    Joined: Jan 2013
    Posts: 29
    Likes: 0, Points: 1, Legacy Rep: 3
    Location: india

    sujeethmonu Asst Professor(mech dept)

    Yeah mailed marcus regarding it. hope it helps in its development. Thanks a lot bro. I learnt a lot from you. Was not knowing about units changing at all.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.