Entry Angle vs Hollow Waterlines

Discussion in 'Hydrodynamics and Aerodynamics' started by Mat-C, Apr 16, 2012.

  1. Leo Lazauskas
    Joined: Jan 2002
    Posts: 2,696
    Likes: 155, Points: 63, Legacy Rep: 2229
    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

  2. philSweet
    Joined: May 2008
    Posts: 2,682
    Likes: 451, Points: 83, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    darn, Leo beat me to it. I had Ad Hoc figured more as a Mother, Jugs, and Speed kinda guy.:p

    http://en.wikipedia.org/wiki/Mother,_Jugs_&_Speed

    (SO I originally underlined the title of the movie, but I looked that up under grammer and found a comment that said-
    Talk about feeling old. I think italics were around when I was in school.)
     
  3. Ad Hoc
    Joined: Oct 2008
    Posts: 7,773
    Likes: 1,678, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Nope, never heard of that film :(

    Surely you were all smitten as over-active teenagers watching Raquel Welch in the 3 Musketeers??? :confused:
     
  4. messabout
    Joined: Jan 2006
    Posts: 3,367
    Likes: 510, Points: 113, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Did Raquel have hollow bows? I thought them rather pleasingly bulbous.
     
  5. Ad Hoc
    Joined: Oct 2008
    Posts: 7,773
    Likes: 1,678, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Oh yes...exceedingly so :D
     
  6. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 208, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    Intensive refinement of low resistance forms rejected any performance advantage to hollow in the bow [fwd waterlines] years ago. It's considered now to be always detrimental.
     
  7. Luc Vernet
    Joined: May 2004
    Posts: 56
    Likes: 3, Points: 0, Legacy Rep: 31
    Location: Vietnam

    Luc Vernet Senior N.A.

    Did I say the opposite??? Too fast reading, MikeJohns.
    Giving historical references and saying why, at that time, something was found beneficial is not in contradiction with later development showing that the opposite is more performing....all other elements being different!
    Not, may I say, a very scientific approach...
     
  8. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 208, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    Luc
    I agree with your post. I was using your opening paragraph to comment particularly on FLH; as a proponent of 'hollow' waterlines. You will find people citing this 'great discovery' of his as not having been rediscovered by current Naval Architects. I had someone telling me this just recently and there seem to be a few around who really believe it.

    Fast sailing ships had some hollow but it is of course small relative to the Froude number ships operate at and was not a feature of enhanced attached laminar flow but traditional construction for a deep forefoot.
     
  9. vandutch
    Joined: May 2012
    Posts: 7
    Likes: 2, Points: 0, Legacy Rep: 20
    Location: French Riviera, France

    vandutch Junior Member

    Professional opinion of this bow structure

    This bow is getting a lot of talk but is it a lot of hype or is it really grounded technically?
     

    Attached Files:

  10. daiquiri
    Joined: May 2004
    Posts: 5,371
    Likes: 258, Points: 93, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    What is so particular about it?
     

  11. vandutch
    Joined: May 2012
    Posts: 7
    Likes: 2, Points: 0, Legacy Rep: 20
    Location: French Riviera, France

    vandutch Junior Member

    That's what I don't get. The marketing jargon is often Kevlar reinforced... vacuum-injected sandwich... Aft... Is it possible to be rare?
     
Loading...
Similar Threads
  1. laukejas
    Replies:
    18
    Views:
    10,082
  2. cristianon
    Replies:
    17
    Views:
    5,583
  3. tropostudio
    Replies:
    9
    Views:
    2,430
  4. quequen
    Replies:
    14
    Views:
    9,779
  5. seandepagnier
    Replies:
    5
    Views:
    1,269
  6. skaraborgcraft
    Replies:
    50
    Views:
    4,564
  7. sun
    Replies:
    5
    Views:
    1,048
  8. sun
    Replies:
    10
    Views:
    1,984
  9. Christian Lucas
    Replies:
    1
    Views:
    1,234
  10. Leif Weisner
    Replies:
    2
    Views:
    2,865
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.