Hi there evry1 - i'm a student at loughborough university currently doing a group project in which we have to design a wing in ground effect craft. (ground effect is a phenomenon whereby a wing flying very close to the ground produces less drag and more lift, just for those of you not familiar with the term!! for an example just search for "the wig page" on google and check out some pics). It is common for these types of craft to take off and land on water, and hence the 'fuselage' must act as a hull.Since the craft produces less drag and more lift, the thrust required at cruise can be as low as 30% of an equivalent aircraft flying out of ground effect. This low thrust requirement means that theoretically a smaller, cheaper, lighter engine could be utilised. Unfortunately, the drag at takeoff is very high due to the water bourne nature of the craft. Therefore, it is common for the engine to be sized for the take off requirements of the vehicle.I therefore need some information on the design of boat hulls, and how drag is calculated - I know what you're thinking, 'why is he asking this question in an aviation forum?'. Well I was thinking that maybe somebody had experience with designing seaplanes, as I should image that they have similar issues with hydrodynamic drag.My research so far has pointed to a 'hump drag' and 'hump speed' that is basically where the hull changes from a displacement regime to a planing regime. If anyone can point me in the direction of some software or equations that could help me in the design of a hull and calculations of hydrodynamic drag, I would be very grateful.Thanks for taking the time to read up to this point!! I would appreciate any information that anyone could offer.Thanks again,Steve

My suggestion is that you look up the Lun Eraknoplan. It was designed in the U.S.S.R for SAR and Anti-Shipping. It was a very large aircraft, so logically its hull would have to be pretty efficent. I'll poke around the net and see if I can help you out more.

Thanks jdu - my group and I have found pretty much everything on every WIG craft that has existed (check out 'The WIG Page' search on google). Whilst this site is great to supply some data - the only thing about hull design it says is that its pretty much a topic in itself and that it need careful consideration!! very helpful!!anyway - if you are bored one day and do stumble across something that may help me, then I would appreciate it alot!Thanks againSteve

Hi Steve:I found this website a while back and thought I would share it with you.. http://www.grc.nasa.gov/www/K-12/freesoftware_page.htm There is some great info and some great little programs that might help you with airfoils etc. I hope you find it useful....cheers Brent