A bright orange sailboat with solar panels on the wing sail and the hull of the craft. A number of protuberances from the wing are visible containing instruments and radio equipment.

Saildrones Searching The Sea For Clues To Hurricane Behavior

July 29, 2024 by Navarre Bartz 26 Comments

Hurricanes can cause widespread destruction, so early forecasting of their strength is important to protect people and their homes. The US National Oceanic and Atmospheric Administration (NOAA) is using saildrones to get better data from inside these monster storms.

Rising ocean temperatures due to climate change are causing hurricanes to intensify more rapidly than in the past, although modeling these changes is still a difficult task. People on shore need to know if they’re in store for a tropical storm or a high strength hurricane to know what precautions to take. Evacuating an area is expensive and disruptive, so it’s understandable that people want to know if it’s necessary.

Starting with five units in 2021, the fleet has gradually increased in size to twelve last summer. These 23ft (7m), 33ft (10m), or 65ft (20m) long vessels are propelled by wing sails and power their radio and telemetry systems with a combination of solar and battery power. No fossil fueled vessel can match the up to 370 days at sea without refueling that these drones can achieve, and the ability to withstand hurricane winds and sea conditions allow scientists an up-close-and-personal look at a hurricane without risking human lives.

We’ve covered how the data gets from a saildrone to shore before, and if you want to know how robots learn to sail, there’s a Supercon talk for that.

Thanks to [CrLz] for the tip!

An image of a man in glasses in a circle placed on a black background. The title "Pierce Nichols: Teaching Robots to Sail" is on white lettering in the bottom left corner.

Supercon 2023: [Pierce Nichols] Is Teaching Robots To Sail

July 19, 2024 by Navarre Bartz 12 Comments

Sailing the high seas with the wind conjures a romantic notion of grizzled sailors fending off pirates and sea monsters, but until the 1920s, wind-powered vessels were the primary way goods traveled the sea. The meager weather-prediction capabilities of the early 20th Century spelled the end of the sailing ship for most cargo, but cargo ships currently spend half of their operating budget on fuel. Between the costs and growing environmental concerns, [Pierce Nichols] thinks the time may be right for a return to sails.

[Nichols] grew up on a sailing vessel with his parents, and later worked in the aerospace industry designing rockets and aircraft control surfaces. Since sailing is predominantly an exercise in balancing the aerodynamic forces of the sails with the hydrodynamic forces acting on the keel, rudder, and hull of the boat, he’s the perfect man for the job.

While the first sails developed by humans were simple drag devices, sailors eventually developed airfoil sails that allow sailing in directions other than downwind. A polar diagram for a vessel gives you a useful chart of how fast it can go at a given angle to the wind. Sailing directly into the wind is also known as being “in irons” as it doesn’t get you anywhere, but most other angles are viable.

After a late night hackerspace conversation of how it would be cool to circumnavigate the globe with a robotic sailboat, [Nichols] assembled a team to move the project from “wouldn’t it be cool” to reality with the Pathfinder Prototype. Present at the talk, this small catamaran uses two wing sails to provide its primary propulsion. Wing sails, being a solid piece, are easier for computers to control since soft sails often exhibit strange boundary conditions where they stop responding to inputs as expected. Continue reading “Supercon 2023: [Pierce Nichols] Is Teaching Robots To Sail” →

Sailing (Directly) Into The Wind

February 6, 2024 by Bryan Cockfield 22 Comments

Humans have been sailing various seas and oceans for thousands of years, and using boats for potentially even longer than that. But as a species we wouldn’t have made it very far if it was only possible to sail in the same direction the wind is blowing. There are a number of methods for sailing upwind, but generally only up to a certain angle. [rctestflight] wondered if there was some way of sailing straight upwind instead and built this rotary sail craft to test the idea.

Normally a boat sailing upwind will sail approximately 45° into it, then “tack” 90° across the wind until they’re at another 45° angle from the wind, this time facing the opposite direction. This back-and-forth nature is not the most efficient path, so this vessel uses a few propellers to bypass the traditional sail. The first iteration, built on a sleek catamaran hull, uses a large propeller to catch the wind’s energy, then transfers it mechanically through a set of shafts to an underwater prop.

It took a few tries to get the size and pitch of both propellers narrowed down to where the boat would move forward into the wind, but move it does. A second major iteration of the build uses a single shaft with no gears, with the trade-off that neither propeller is facing an ideal direction, but this has the added benefit of the boat naturally pointing itself upwind.

While none of the designs are speed demons, the concept is sound enough. It’s just that, in most cases, performing multiple tacks to get upwind is acceptable compared to the extreme efficiency losses and drag from propeller-driven sailing crafts like these. A more effective way of propelling a boat upwind, at least using modern technology, might be to trade sails for solar panels.

Continue reading “Sailing (Directly) Into The Wind” →

Polynesian Wayfinding Traditions Let Humans Roam The Pacific Ocean

February 1, 2024 by Lewin Day 24 Comments

Polynesian cultures have a remarkable navigational tradition. It stands as a testament to human ingenuity and an intimate understanding of nature. Where Western cultures developed maps and tools to plot courses around the world, the Polynesian tradition is more about using human senses and pattern-finding skills to figure out where one is, and where one might be going.

Today, we’ll delve into the unique techniques of Polynesian navigation, exploring how keen observation of the natural world enabled pioneers to roam far and wide across the breadth of the Pacific.

Continue reading “Polynesian Wayfinding Traditions Let Humans Roam The Pacific Ocean” →

Learn Sailing Mechanics Without Leaving Dry Land

January 20, 2024 by Danie Conradie 31 Comments

The ancient art of sailing can be very intimidating for the uninitiated given the shifty nature of wind. To help understand the interaction of wind direction and board orientation, [KifS] designed a hands-on sailing demonstrator that lets students grasp the basics before setting foot on a real sailboat.

The demonstrator uses a potentiometer as a tiller to control a model sailboat’s angle, while another stepper motor adjusts the position of a fan to simulate changing wind directions. With an Arduino Uno controlling everything, this setup affords students the opportunity to learn about sail positioning and adjusting to shifting winds in an interactive way, without the pressures and variables of being on the water.

[KifS]’s creation isn’t just about static demonstrations. It features four modes that progressively challenge learners—from simply getting a feel for the tiller, to adjusting sails with dynamic wind changes, even adding a game element that introduces random wind movements demanding quick adjustments. [KifS] mentions there are potentials aspects that can be refined, like more realistic sail response and usability, but it already achieved the main project goals.

There are a myriad of potential ways to add new tech to the ancient art of sailing. We’ve seen a DIY autopilot system, full sensor arrays, and an open source chart plotter. It’s even been proven you can have a wind powered land vehicle that travels faster than the wind.

$10 000 Physics Wager Settles The Debate On Sailing Downwind Faster Than The Wind

July 2, 2021 by Danie Conradie 95 Comments

By now, many of you have seen the video of [Rick Cavallaro]’s Blackbird, the controversial wind-powered land vehicle that can outrun the wind. The video has led to a high-profile $10 000 wager between [Derek Muller] aka [Veritasium] and [Alex Kusenko], a professor of physics from UCLA. [Veritasium] won the wager with the help of a scale model built by [Xyla Foxlin], and you need to watch the videos after the break for some excellent lessons in physics, engineering, and civilized debate.

After seeing [Veritasium]’s video on Blackbird, [Professor Kusenko] contacted him and said the performance claims and explanation were incorrect. After a bit of debate [Veritasium] proposed a wager on the matter, which [Professor Kusenko] accepted, and it was made official with a written agreement witnessed by [Neil deGrasse Tyson], [Bill Nye], and [Sean Carrol]. From the start, it was agreed that the entire debate would be made public.

[Professor Kusenko] made a very thorough and convincing argument, backed by calculations, against the claims in the video. He claimed the observations were due to a combination of gusty winds, a vertical wind gradient. He was convinced and that the vehicle would not be able to maintain a speed higher than the wind, directly downwind. By [Veritasium]’s own admittance, his original video could have contained more details and proof of performance claims of the Blackbird vehicle. He added these to the latest video and included two model demonstrations. The model that brought the concept home for us is at 13:46 in the video, and substitutes the propeller for a large wheel being driven by a piece of lumber being bushed across it. The second model, built by [Xyla Foxlin] was designed to demonstrate the concept on a treadmill. The 4th version of [Xyla]’s model was the first to be successful after she found out from [Rick Cavallaro] that the key design detail is the Vehicle Speed Ratio, which must be 0.7 or less. It is the pitch of the propeller divided by the circumference of the driven wheel, assuming a 1:1 gear ratio. All the 3D files and details are available if you want to build your own downwind cart. Continue reading “$10 000 Physics Wager Settles The Debate On Sailing Downwind Faster Than The Wind” →

Sailing Faster Than The Wind Itself

June 6, 2021 by Jenny List 136 Comments

If you search the outer reaches of the internet you will find all sorts of web sites and videos purporting to answer to free energy in the form of perpetual motion machines and other fantastical structures that bend the laws of physics to breaking point. We’d love them to be true but we have [Émilie du Châtelet] and her law of conservation of energy to thank for dashing those hopes. So when along comes a machine that appears to violate a fundamental Law of Physics, it’s reasonably met with skepticism. But the wind-powered vehicle built by [Rick Cavallaro] looks as though it might just achieve that which was previously thought impossible. It’s a machine that can move with the wind at a speed faster than the wind itself.

A fundamental law of sailing boats is that when they are sailing with the wind, i.e. in the same direction as the wind, they can’t sail faster than the wind itself. Sailing boats can go faster than the wind powering them by sailing across it at an angle to create lift from their sails, but this effect doesn’t work as the angle tends towards that of the wind.

The vehicle in the video below the break is a sleek and lightweight machine with a large propeller above it, which we are told is not the windmill power source we might imagine it to be. Instead it mimics the effect of a pair of sailing boats sailing across the wind in a spiral around a long cylinder, and thus becomes in effect a fan when turned by the motoin in the craft’s wheels. The drive comes from the wind working on the craft itself, and thus as can be seen from the motion of a streamer on its front, it can overtake the wind. It seems too good to be true at first sight but the explanation holds water. Now we want a ride too!

For fairly obvious reasons, the fantastical world of pseudo-physics isn’t our bag here at Hackaday. But if something might hold promise we’ll at least give it a look. Not all such things we cover turn out to change those Laws of Physics, though.

Continue reading “Sailing Faster Than The Wind Itself” →