Suggested techniques to go against the current.

[PhiTran]

I have posted videos to demonstrate several techniques to help one to go against the current using the power of the current itself as if one is sailing with the wind power, this use the hydro power instead.

They are:
http://www.youtube.com/watch?v=acSY1B-q ... tube_gdata" onclick="window.open(this.href);return false;

This second video is showing that by changing the attack angle one can move the boat (models) up, down, etc

http://www.youtube.com/watch?v=bBsYSCI0 ... tube_gdata" onclick="window.open(this.href);return false;

Thanks for your watching to see if it can help.

And final: Have fun.

Phi

[Todd]

I don't get it, what am I missing?

[JSnooky]

See this is exactly what we are talking about Todd! You are fighting the current my friend, just go with it brother! lol.

[PhiTran]

It is my experience in several discussions that for some "LOL" or ridicule are their first reactions, because this may be the first attempt to hydro sailing. However it's worthwhile to think it may not be the last L.
Thanks
Phi

[Todd]

Ok, understandable, can you put this in laymans terms?

[jbdba01]

I didn't quite follow the videos either. Guess I'm a bit slow. However, last year when I was just getting into kayaking I saw this guy going into the current. I was like WTH? What am I doing wrong? He was flying! Seriously.

[PhiTran]

If one can build his/herself one or two paddle like wing shape devices (video 1) the you can use that to push your boat upstream by just stick them on the side of the boat. (in technical term wing shape device is called airfoil)

In both videos water current is from the left to the right.

In other discussion some think that it is a fake or I use other video trick to have the models flow upstream then the video 2 was shot to show that by fool with the foil (changing the angle) one can have the boat flow up or down stream.

Thanks.

Some may ask for the physical principle behind the phenomena then readings ; on the net; about airfoil, hydrofoil, and sailing (against the wind) will be very much help.

Phi

[jbdba01]

If I understand what you are presenting you are saying you can tack into the current using the foils on the model - correct?

Sounds like you're saying the speed of the current + the angles of the foils propels the boat forward. Which I don't quite follow because I would have thought that the friction and drag of the hull would have been greater than the propulsion. Which kinda hurts my head.

I get how a sail works, but I would have figured the drag of the foils + the hull friction would be too much to overcome.

[PhiTran]

If I understand what you are presenting you are saying you can tack into the current using the foils on the model - correct?

Sounds like you're saying the speed of the current + the angles of the foils propels the boat forward. Which I don't quite follow because I would have thought that the friction and drag of the hull would have been greater than the propulsion. Which kinda hurts my head.

I get how a sail works, but I would have figured the drag of the foils + the hull friction would be too much to overcome.

By nature of fluid dynamic a foil when hitting the current, there are two forces appear the "lift" and the "drag". When the "lift" is greater then the "drag" the the device move upward the current. This happens when one sails zigzag against the wind; however if one is to sail with current - he/she only uses the "drag" force.

Phi.

[UrbanLegend]

So essentially what you're saying is that based on the shape of the craft, or placement of the foils, more water is displaced over a larger surface area from the front of the craft and the rear basically "rides" the wake created by the foil, or foils, to propel the vessel forward? It’s neat to see how it works in the model realm, but have you figured out what the ratio of dual or single foil to kayak size would need to be to make it work effectively?

Seems like a similar philosophy to aerodynamics. The shape of an airplanes wings allows more air to pass under the wing than on top, creating lift. I would suspect that there would have to be a certain amount of current flow based on the weight of the person, kayak and gear to create enough lift to overcome that amount of drag. Either that or the length, angle, or number of foils would have to be adjusted.

http://coolestgadgetsandgizmos.com/2010 ... atercraft/" onclick="window.open(this.href);return false;

http://www.google.com/imgres?imgurl=htt ... m=1&itbs=1" onclick="window.open(this.href);return false;

[PhiTran]

So essentially what you're saying is that based on the shape of the craft, or placement of the foils, more water is displaced over a larger surface area from the front of the craft and the rear basically "rides" the wake created by the foil, or foils, to propel the vessel forward? It’s neat to see how it works in the model realm, but have you figured out what the ratio of dual or single foil to kayak size would need to be to make it work effectively?

It should not be very big, since the water is about 1000 times the force of the air (wind). On my models I use my rule of thumb of the area of the foil(s) having about a 1.5 the cross section area of the "boat".

I also use about 75% the cross section area but it does not work very well with the slow stream.

[Rik]

If you go to the website shown on the vid - http://www.neo-aerodynamic.com/" onclick="window.open(this.href);return false; - you can read more about it. Interesting concept. While we don't often deal with much current around here (or maybe it is that we avoid places with current) there have been times when it would have been nice. Paddling back into Chokoloskee against the current is one of those times!

[UrbanLegend]

Since this technology has been used for larger craft to increase efficeincy (and some concepts for smaller personal recreation-like jet skiis) are you looking into some sort of patent or application for smaller self-propelled craft?

[PhiTran]

. . . .
Seems like a similar philosophy to aerodynamics. The shape of an airplanes wings allows more air to pass under the wing than on top, creating lift. I would suspect that there would have to be a certain amount of current flow based on the weight of the person, kayak and gear to create enough lift to overcome that amount of drag. Either that or the length, angle, or number of foils would have to be adjusted.

http://coolestgadgetsandgizmos.com/2010 ... atercraft/" onclick="window.open(this.href);return false;

http://www.google.com/imgres?imgurl=htt ... m=1&itbs=1" onclick="window.open(this.href);return false;

You relate to hydro foil it is different application of the foil technology. Hydro foil is using the foil + speed to lift the watercraft vertically greatly reduce the drag so the craft can move faster.

Here we are attempting to use the current to craft the "lift" force but forward, horizontally to pull along it with the "boat". It does not work without a current such as the lake, pond . . . .

[PhiTran]

FYI:

This is the current practice to move a boat upstream without the help of an engine.

http://www.criticalpast.com/video/65675 ... ng-on-boat" onclick="window.open(this.href);return false;
Or.
http://www.corbisimages.com/stock-photo ... llow-river" onclick="window.open(this.href);return false;


The sample I posted simulate the heavy loaded watercraft.

[Todd]

Two words-Tide Charts.