Question Bout Bulb Research... Urgent

Discussion in 'Boat Design' started by Torrey, May 26, 2006.

  1. Torrey
    Joined: Apr 2006
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 9
    Location: Indonesia

    Torrey New Member

    Hi... I want to ask some question about bulbous bow.... hope anyone read this and reply it.... cause it's urgent...
    here... i'm doing a reseach about bulbous bow eficiency with a ship model test....
    after i got all the resistance of ship model datas.. i kinda confuse .. how to calculate the resistance with include the bulbous bow factor
    what i know is.... i can use holtrop formula... but the formula is for the real ship.... n my datas is for the model...
    should i scale the boulbous bow first to the real size then use the holtrop formula
    or i just can use the holtrop formula with the model's data
    -- sorry if my english is hard to understand... i do my best.... n i'm very gratefulll for any information....----
    best regards
    ToRRey
     
  2. jehardiman
    Joined: Aug 2004
    Posts: 3,781
    Likes: 1,174, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    First, seperate the model data into frictional resistance and form resistance. From that you can calculate the effect of the bulb on form resistance (the bulb effect ratio). Then work out the full size resistance using Holtrop-Mennen without the bulb. Extract the full scale frictional resistance to leave the form resistance. Apply the bulb correction from the model data. Reapply the full size frictional resistance including any bulb area.
     
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.