The Unexpected Genius of Bionic Propellers

propellers are incredible you might not think about them often but as I've learned propellers have and cause considerable problems that are affecting some of the most endangered animals on our planet like magnificent whales who can become confused due to unfamiliar noises underwater so I've been reading up on some unique Solutions inspired by the very nature that they are threatening I also 3D printed one of these new propellers so I could get my hands on one of these counterintuitive designs when biologist Frank Fish first saw tubic on models of a humpback whale in a Boston gift shop he thought the designer had made a mistake the owner of the shop had to show him a photograph to prove they were accurate as a result Dr fish studied these intensely and what he found was truly incredible but first I want to show you what I think makes propellers so fascinating as you may know the rght brothers revolutionized propellers for Flight by treating them as rotating wings and although they've evolved a lot since 1903 they still broadly look the same the smooth blades cut through either water or air and create a pressure difference this pressure difference pushes the fluid backwards and creates an equal and opposite forward Force this principle is used to propel vehicles through and underwater and across our skies a similar concept also harnesses kinetic energy from wind and water as flowing fluids create pressure differences that turn turbines in a way it's kind of simple and it works but I couldn't help but think there has to be some room for improvement in a couple of other videos I looked at how teroid propellers work and ever since I've been hooked on propellers what I learned whilst researching this video is that applying principles from nature is totally transforming propeller design resulting in some surprising new shapes what I found focuses on biometic solutions to two major problems that traditional propellers have the first problem affects Marine propellers it's called cavitation and sends shivers down the spines of ship and Boat Owners everywhere cavitation happens due to a sudden pressure drop on the low pressure suction side of the blades the droping pressure near the propeller causes the water to literally vaporize and small vapor-filled bubbles form as these bubbles collapse microjets shoot out from them and Hammer the propeller significantly reducing efficiency the bubbles also erode the blades and have even been reported to end up tearing off the blade completely on top of that cavitation costs the maritime industry Millions every year and causes a lot of noise but we'll get onto that later the second major problem traditional propellers have is controlling the drag the balance between thrust and drag can be hard to manage and ultimately affects propeller efficiency though a certain amount of drag does go hand inhand with the thrust in propellers or lift in turbine blades as turbine or propeller blades go through w water or air it causes fluid to flow over them this fluid ideally wants to flow in a smooth and controlled way so that it stays stuck to the blade if the fluid separates from the blade too quickly drag can start to dominate and if it separates completely it leads to a store this is why up until now blades have always had smooth edges for streamlining another important factor in controlling drag is managing the angle of attack between the blad's edges and the direction of the oncoming fluid if the angle is too big fluid comes off the upper surface too quickly creating drag and excess turbulence so it's safe to say it needs to be designed with Precision especially with blades moving at speed so from my reading those seem to be the two main problems with traditional propellers cavitation and excess drag and then there's the problems that they cause the whoosing sounds of wind farms could be pretty irritating if you live very close but with cavitation in the mix underwater it gets gets way worse this is bad for submarine stealth but for marine environments this can be pretty devastating propellers share the ocean with marine mammals combined with the mechanics of their operation propellers cavitation and drag produces underwater radiated noise as loud as a rock concert reaching up to 180 DB it is also comparable to watching a rocket lift off and can be heard by sea creatures 100 m away in the cold shallow Waters of the Arctic where sound travels quickly boats are literally drowning out the voices of whales and other mammals with underwater noise pollution it's impacting their feeding and breeding separating mothers from calves and even causing hearing loss the good news is I've been finding loads of incredible R&D work that is aimed at solving this challenge gamechanging bonic propellers inspired by ski skaters birds and whales help to reduce drag and cavitation and therefore noise the first propeller I found is a bit of a wild card but I thought I'd share it with you before getting to some of the more mature designs the propeller is inspired by the incredible green crested basilisk known as the Jesus Christ lizard you can see where this nickname comes from this semi amphibious rainforest creature runs on water to escape Predators part of the secret behind this superpower is the ability to adapt the pitch of its feet to the flow of the water as they enter and exit the angle of attack on Entry creates lift and thrust simultaneously and a vertical exit reduces drag a team of researchers wanted to see if they could copy this idea to make a robot walk on water using a paddle propeller instead of legs so they designed a variable pitch water treading propeller using planetary gears it did take me a second to visualize this but as the propeller spins the linkages and paddles act like legs and feet going in and out of the water a Sim ulation showed increased efficiency versus a standard paddle propeller but it would be incredibly complex to engineer either way there's some exciting potential here for some unusual robotic propulsion skis skaters are a kind of insect living on the open ocean their body hairs trap air inside microscopic mushroom-shaped cavities if they're accidentally submerged this helps them breathe and stay a float this is the inspiration behind biometic materials called Gems or entrapping microtextured surfaces researchers found that by copying the mushroom shaped cavities instead of a flat surface they could largely prevent damage from cavitation this is because as the cavitation bubble forms air trapped in the mushroom structure below expands and pushes The Unwanted micro jet outwards away from the surface it's still in the research phase but gems could mean a new biometic propeller surface that reduces cavitation and propeller wear next up we have the mighty humpback whale who are incredibly acrobatic for their size one of the secrets of their agility is their fins which help them achieve Great Lift thrust and therefore maneuverability so you'd think they'd be smooth to be so Hydro dnamic but they're not they're actually covered in big rounded bumps called cubicles researchers have studied these intensely and discovered the tubal effect tubic channel the water that flows over the front of the fins into narrow streams this creates high energy areas that help reduce drag because the smooth separate flows are less likely to separate from the blade or air foil this same principle allows the fins to have higher angles of attack before it stalls meaning is possible to increase the amount of lift experiments and real world testing of wing models based on the whales fin show that this lowcost low maintenance passive flow control improves performance for marine propellers it even reduces cavitation and again reduces noise this is actually the small scale bionic propeller that I 3D printed look at these blades not smooth at all like the ones I thought would be best for streamlining these are the bumpy edges that direct the fluid flows and reduce drag the amplitude and wavelength of these bumps are also tunable for each application now this is obviously a pretty tiny example and I'll leave a link to the cad file for it from RS razza below but imagine this on a much bigger scale there are a few things holding this promising technology back from Mass Production but that doesn't mean there aren't some tried and tested bionic propellers out there this is where our friend Dr fish comes in since his Discovery in that Boston gift shop he's become a world expert on bionic propellers and the cubicle effect he also formed a company called whale power to make commercial applications for this counterintuitive technology whale power say their bionic propellers ACH achieve 20% Energy savings improve efficiency have greater stability and as a result improve durability and you probably guessed they are also quieter when they tested a prototype back in 2008 they found that the turbine had survived being hit by the edge of a hurricane and it survived wind driven snow and ice a company helping make these bionic propeller designs a reality is Big WP their industrial scale 3D printers can play a huge role in this Innovation because they can quickly print shapes that would take a lot of time and effort to manufacture with more traditional methods they teamed up with researchers from a Berlin University to produce this bionic propeller just like a bird's Wing the tips of its blades All Join and you see the ridges on the blade edges those are its very own cubicles which allow fast rotation of the blades with less trag big rep mentions that these could work with just about anything that has a rotating blade from ventilation fans and wind turbines to ships and boats and planes according to Big rep results of their tests on a ship showed a 19% increase in thrust performance they also say cavitation is reduced but not by how much and although it was only tested on a computer vent the really exciting result they reported is that noise emissions were down by 30% despite these promising results I think there are two main challenges for getting bionic propellers to be fully commercial one is that although tubic are proven to be effective their placement on propellers is not straightforward the optimal size and layout of the tubic defined by the amplitude and wavelength varies according to different factors and conditions so more work is needed and as we've already seen with their unusual and intricate shapes the economic production of bionic propellers is limited by manufacturing constraints but 3D printing on an industrial scale could be an important component in helping this 3D printing can reduce the cost for low volume production and also prototypes that are vital to refining designs for specific applic apption can be quickly iterated upon it may be a while before we see bionic propellers everywhere but the number of patent applications related to bionic propeller technology and the sheer volume of exciting research going on is a good indicator of things to come to me they're bound to follow the same path as the propellers of today the same path as light bulbs there may be a widely held belief that these inventions came from one Innovation or one inventor but we know that's not true both took the work of many people many hands and many Minds to come to fruition and as you're still watching please subscribe to the channel as I think you'll like some of the other videos I make like this one on a bionic winged drone also if you know about any other interesting propeller designs please let me know in the comments below thanks for watching

Channel: Ziroth

Views: 1,697,323

Keywords: Science, Engineering, STEM, Electric, Zero, Tesla, News, Research, EV, Battery, transport, propeller, drone, ship

Id: WezeLNC32sA

Length: 11min 48sec (708 seconds)

Published: Thu Dec 07 2023