three questions

[susheng999]

hi everybody:
i am new member. when i design a high speed boat, i have three questions, one is how to exactly estimate the displacement, the second is how to know the hull lines is good. the third is how to calculate the speed.

[alan white]

Those are questions that are not easily answered here. Each question would take a chapter in a book to explain, and that's why I'd recommend you get a good book on the subject. Displacement is the easiest to calculate. The other two questions are not so easy. It take a lot of math and some experience too to figure out if a design is good or not (good in what way?).
Speed is related to the design, so it's the same basic question--- is the design good?
Usually, a design goal is set. The design goal, or brief, is a description of which factors of design are most desired, and which are not. The fastest boat will not be the most seaworthy. The boat with the most comfort won't be fastest. "Good hull lines" means good hull lines for the purpose for which the boat is required to fulfill, so an all-out racing boat with good lines has unsafe and uncomfortable lines if you want a vessel meant to cross oceans quickly.

[FAST FRED]

Start out with the fuel consumption you are willing to pay for ,

then factor in that speed VS sea state with a limit of 3G's to see what is practical in terms of human occupanct.

FF

[peter radclyffe]

Originally Posted by susheng999

hi everybody:
i am new member. when i design a high speed boat, i have three questions, one is how to exactly estimate the displacement, the second is how to know the hull lines is good. the third is how to calculate the speed.

go to college

[PAR]

Designing a high speed powerboat isn't something you should be considering, until you have a much firmer grasp of the concepts, principles and dynamics involved. Getting this requires an education, which can be correspondence if desired. The engineering alone will require considerable study on your part. Once familiar with the engineering necessary you'll have a clue about what other research will be necessary to complete the many tasks necessary in a high speed powerboat. Since you're using MaxiSurf, you have a head start, but there's a fair bit more for you to learn yet.

[susheng999]

Thank You Very Much!
I Have Learned More From Your Reply.

[mydauphin]

Originally Posted by peter radclyffe

go to college

Hey, I designed and built many boats thru trial and error. Expensive, but more fun than doing by knowing what your doing. Of course I would never travel too far in them, sell them and we did test them step by step.

Look at others boats, copy their designs, find out why they do what they do.
It is a great hobby, just be careful. Get some old guy to mentor you on how to build fiberglass boats. Read books. Is your boat going to be the best or fastest probably not, but that is part of fun. Again it is not cheap just like college.

[MikeJohns]

Originally Posted by susheng999

hi everybody:
i am new member. when i design a high speed boat, i have three questions, one is how to exactly estimate the displacement, the second is how to know the hull lines is good. the third is how to calculate the speed.

There is another option if you lack the NA skills and a lot of designers do this; style the boat above the waterline and pay someone else to design the hull and structure with all the rights going to you. It is then your design.

[susheng999]

Thank You Very Much!
A Lot Of Experience Is Very Important.