Dynamic Stability and Chine Riding

[tkdchris]

I'm designing a 45ft ciggerette style boat capable of 60+knots and am very aware that the handling at high speeds is very important.

I have read up about dynamic stability and chine riding effects in 'Yacht Design Principles' by Larsson but at no point does it suggest how this can be deduced.

Any help would be greatly appreciatied

Chris

[gonzo]

Chine riding at that speed will get the boat out of control and probably end up in a bad accident. How much experience do you have in design, particularly of high speed craft?

[tkdchris]

Its my final year uni project, so the boat will never be built but ideally need to cover it in the report to show that i've considered it

Chris

[gonzo]

Cigarette boats have a continuous deadrise all the way forward. The dynamics are pretty complex and I believe not fully understood. Lifting strakes add to the complication. Most designers use existing boats as models. Very rarely will you find a boat that is a complete radical departure from existing designs. Do you have access to line plans of speedboats?

[Tad]

Find "Dynamic Stability of Planing Boats" by Blount and Codega, published by SNAME in Marine Technology January 1992 as a start, there are some subsequent papers by both authors as well......

Also for example hulls see two recent issues of Professional Boatbuilder with a two part piece by Michael Peters on high-speed boat design .......

[Mr Efficiency]

Just specify suitable trim tabs and problem solved. Maybe.

[Submarine Tom]

Sounds like it just has to work theoretically.

You may want to mark that down somewhere on the plans in case your great-grandson finds them in the attic one day, builds one and then kills himself in it...

-Tom

[David Cockey]

Blount dynamic stability calculator page: http://dlba-inc.com/DSC.htm
The calculator can be downloaded for free. It's empirical and I don't know to what extent it addresses chine walking.

I recall an excellent presentation at the 1979 AIAA/SNAME Advanced Marine Vehicle Conference in Baltimore on drag (as in racing) boat dynamic stability including chine walking. The presenter's day job was owner and chief engineer of a medical devices/implant company in Tennessee if I recall correctly. He raced drag boats as a hobby and was concerned by the accidents which occured due to the boats becoming dynamically unstable. His presentation covered both experimental data and analysis, and was very well received by the audience.

[sottorf]

does anybody have a copy of the Michel Peters articles in Proboat on Fast Powerboats that they can share?