HYDROFOIL--Technical Video of a Testing Tank, A Ray Vellinga video

[rvell7829]

Answer to SuperRonArt.

There are 18 hydrofoil videos by me (2,600,00 views to date). I will guess that you refer to Hifybe, high Flying Banana. It uses a forward mounted surface follower that is attached to the front strut by a flexible shaft that springs and dampens as waves are encountered.

Please describe your "float in a tube".

BTW, see: 'Save $20--Don't buy this book' video. Or Just buy my book, "Hydrofoils, Design, Build, Fly", at Amazon.com.

Ray Vellinga

[TheTuanshipland]

I am an engineer of naval architecture and marine engineering at Institude for Computational Science and Technology in Ho Chi Minh city in Vietnam.

My name is Tuan Anh Nguyen, you can call me "Tuan Shipland".

May I discuss some issues of hydrofoil with you? What is your email, Prof. Vellinga?

Waiting for your reply,

Best regards,

Tuan Shipland

sites.google.com/site/tuanship­land

[Ninjavaz]

The real ones couldn't fly in any following sea conditions but were totally outstanding in beam seas. The SAS system made the later models very easy to fly and the pitch control very responsive. We operated them here from the early 60's till the early 90's when they were replaced by the wave piercing catamarans. Quite remarkable craft and seakeeping was second to none for the size of the craft.

[whatzupa]

I've been on the full size Curl Curl when they were in service from Circular Quay to Manly. They are still in service somewhere in the world, I remember they were sold to an Asian country when they were decomissioned, I can't remember which one now.

[aliscafi]

@whatzupa, The three hydrofoils that were last in service on Sydney Harbour (Sydney, Manly, Long Reef and Curl Curl) were all returned to Italy on a ship. With the exception of Long Reef they all saw further service in Europe or elsewhere. Curl Curl is understood to still survive and was last known by the name Spargi.

[SuperRonArt]

Dumb question(?) In a previous test on a lake, you used a floating gadget (I couldn't make out what it was) ahead of the small boat. It slapped around. Have you tried using a float in a tube (to average out the waves)?

[aliscafi]

@SuperRonArt, you would be referring to a video of Hyfibe built by Ray. The float was a surface sensor he used to control the angle of incidence of the bow foil. This keeps the craft running at a level trim. A float in a tube would likely not respond quickly enough and may cause more drag with less control forrce than his float approach.

[Ninjavaz]

Good video, Thanks for posting. Interesting technology that produced outstanding results as long as the engines performed at 100% power.

[aliscafi]

Thanks for the message. These tests were conducted at the towing tank at the Australian Maritime College (AMC) in Tasmania as a private activity with thanks to the Towing Tank Manager, Gregor MacFarlane.

[Theriomalstrom]

Did the rear foil stall @ 2:48? That would be scary for the passengers...

[aliscafi]

Good question. I also wondered about the cause of these plunges. Ray has only posted a small selection of the test runs here, but such sudden plunges also occurred on other runs to various degrees by both the bow and stern. As it also occurred in calm water, I attribute it to sudden ventilation of the foils rather than stalling. The model was fitted with fences representative of the full scale hydrofoil. My feeling is that ventilation is more a problem at model scale than at full scale.

[Vintabilly]

I'm glad that a sea state that produces speed robbing hull contact was included in these tow tests. :)

Valuable video, favorited thank you. I'll check out the book too.