The Magnus effect is a interesting and useful phenomena. [James Whomsley] from [Project Air] decided to put it to work on a small radio-controlled boat, successfully harnessing the effect. (Video, embedded after the break.)
The Magnus effect is an interesting thing, where fluid flowing over a rotating object generates an aerodynamic force at a right angle to the direction of the flow and the axis of rotation. (It’s why curveballs curve.) This can be used for propulsion on a boat, by spinning a tall cylinder called a Flettner rotor. This takes advantage of Magnus effect to generate thrust.
The boat uses a 3D-printed hull, sealed up with a leak sealer spray and lots of spray paint to avoid leaks. In the center of the catamaran design, there’s a spinning rotor belt-driven by a brushless motor. Outside of the rotor for thrust, a simple rudder is used for steering.
With the rotor turning, the boat was able to successfully sail along with the benefit of the thrust generated from the wind. However, there were teething issues, with heavy winds quickly capsizing the boat. [James] realized that adding some proper keels would help avoid the boat tipping over.
Conventional airfoil wings have come out on top for getting flying machines airborne over the last century, but there were a few other interesting designs that have come and gone. One of these is the Magnus effect plane, which makes use of the lift produced by a spinning cylinder. [James Whomsley] from [Project Air] decided to build one as a side project, but it ended up being a lot more challenging than what he initially suspected. (Video, embedded below.)
The Magnus effect achieved a bit of viral fame a few years when [How Ridiculous] dropped a basketball down a dam wall with some backspin. [James] T-shaped Magnus effect plane has a pair of spinning cylinders at the top to create lift, driven by a brushless motor using a belt. A second brushless motor with a propeller is on the center carbon fiber tube provides forward thrust, and a rudder provides yaw control. The battery is attached to the bottom of the tub for stability.
The very first flight looked very promising, but [James] quickly ran into a series of problems related to center of gravity, power, pitch control, and drag. After iterations of the build-crash-rebuild cycle, he ended up with larger motors and rudder, shorter “wings”, and a higher thrust motor position. This resulted in a craft still only marginally controllable, but stayed in the air for quite a while. Since the intention was never to turn it into a long-term project, James] called it a success to avoid more yak shaving, and continue work on his airboat and rocketplane.
If you are interested in building one of your own, he put all the findings of his experimentation in a short report. For more inspiration, check out the other Magnus effect plane we covered that used KFC buckets for the wings.
It’s really beginning to feel as though the problem of climate change is a huge boulder rolling down a steep hill, and we have the Sisyphean task of trying to reverse it. While we definitely need to switch as much of the planet over to clean, green energy as soon as possible, the deployment should be strategic. You know, solar panels in sunny places, and wind turbines in windy places. And for the most part, we’re already doing that.
In the meantime, there are also natural disasters to deal with, some of which are worsened by climate change. Eastern and Southeast Asian countries are frequently under the threat of typhoons that bring strong, turbulent winds with them. Once the storms pass, they leave large swaths of lengthy power outages in their wake.
Studies have shown that these storms are gaining strength over the years, leading to more frequent disruption of existing power systems in those areas. Wind power is the ideal solution where storms have come through and knocked out traditional power delivery all over a region. As long as the turbines themselves can stand up to the challenge, they can be used to power micro-grids when other delivery is knocked out.
Bring On the Typhoons?
Unfortunately, the conventional three-bladed wind turbines you see dotting the plains can’t stand up to the awesome power of typhoons. But vertical axis wind turbines can. Though they have been around for many years, they may have finally found their niche.
[PeterSripol] has made an RC model airplane but instead of using normal wings he decided to try getting it to fly using some KFC chicken buckets instead. Two KFC buckets in the place of wings were attached to a motor which spins the buckets up to speed. With a little help from the Magnus effect this creates lift.
Many different configurations were tried to get this contraption off the ground. They eventually settled on a dual prop setup, each spinning counter to each other for forward momentum. This helped to negate the gyroscopic effect of the spinning buckets producing the lift. After many failed build-then-fly attempts they finally got it in the air. It works, albeit not to well, but it did fly and was controllable. Perhaps with a few more adjustments and a bit of trial and error someone could build a really unique RC plane using this concept.