Close

DLBA UNIVERSITY

Froude for Thought
Getting Semi-Planing Hull Resistance Right

APRIL 28, 2020

By

Dr Robert Ranzenbach

Donald L. Blount & Associates, Inc

 

The first step in having an efficient boat is to have an appropriate hull form for the intended vessel size and speed range. Most new recreational vessel designs today, with the exception of small outboard powered craft, fall into the non-dimensional speed range referred to as semi-displacement or semi-planing. While some people believe there are some minor technical differences in the terminology, we at DLBA believe they are one in the same. Living and operating in that range, there are a range of well known hull shapes and features that perform well.  This paper provides a great beginner’s summary into the technical nuances of what it means to be in the semi-planing regime, and discusses the design parameters, hull shapes, and appendages that can be incorporated to keep hull resistance low.  Tuning the vessel’s hull and propulsion system to have low resistance is good for both the environment and the wallet!

 

The article was published in the Yacht Report, please click on the image below to download the PDF.

Conclusions

Growing numbers of megayacht designs are being constructed as semi-displacement or semi-planing yachts. The analysis of public domain tow tank data has identified the dominant influence of hull form and slenderness ratio over this intermediate operating regime. It is hoped that this information will assist naval architects in the early design stages by providing optimal minimum resistance targets.

 

 

In case you would like to receive more information, or speak with us about  this subject, please contact Jeffrey Bowles.

Share this article online:

Share on facebook
Share on linkedin
Share on twitter
Share on whatsapp
HOW CAN WE HELP YOU?
FEEL FREE TO CONTACT US
DLBA_Naval_architects_bluelogo_1

DLBA Naval Architects

860 Greenbrier Circle, Suite 201  Chesapeake, Virginia 23320 USA

Phone: 757-545-3700  |  Fax: 757-545-8227  | dlba@gibbscox.com

STAY UPDATED

SIGN UP FOR OUR NEWSLETTER

Keep your finger on the pulse of the latest points of focus in naval architecture and engineering: subscribe to DLBA’s concise monthly newsletter. Within it, we briefly describe and picture our latest projects and concepts. We encourage feedback and seek to have our newsletter spark conversation regarding potential collaborations and further advancements as we share our passion for the industry.