The Electric Reincarnation of the Gyrodyne

hello in this video we are going to show how electric propulsion is the perfect technology to solve one of aviation's biggest enigma the compound aircraft that is the aircraft with both rotary and fixed rings we will have a look at aviation history understand the aerodynamic concepts and review modern technological advancements to finally arrive at the point where we can get a glimpse of the future of advanced compound aircraft on this channel electric aviation we bring for you all the latest developments from the world of sustainable air travel subscribe to get all of our updates the idea of urban air mobility is not new the interest in it of late is because of the possibilities that electric aircraft bring which is cheaper quieter more accessible and less polluting mode of air travel delving into aviation history we find that the idea of airlifting passengers from the city center is decades old in fact it was in the 1950s that the development of british aircraft fairies rototine began for this very purpose that is to transport passengers from the city center to airports or between cities the road to line was a remarkable compound aircraft that was ahead of its time and could be best described as a 40 passenger airline with all the capability of a helicopter during its flight tests it achieved what it was meant to achieve it flew at 190.9 miles per hour which was a record for being the fastest aircraft in its category it completed a 60 mile circuit with successful transition from vertical to horizontal and then back into vertical flight during the horizontal flight up to half of the lift was provided by the fixed wings which helped it to attain high speed and gave it longer range it could hover with one engine shut down and its propellers feathered furthermore the rotodyne could operate at half the seat mile cost of helicopters unfortunately because of dwindling economy lack of political support the ferry's rhododyne project was cancelled it also didn't help that the noise level of the aircraft was too high by the time the plug was pulled the rotadyne had flown almost thousand people for 120 hours in 350 flights and conducted a total of 230 transitions between helicopter and autogyro and most importantly with no accidents it is said that at the time of cancellation the noise reduction program for the rotating had already achieved lowering the noise level from 113 decibels to 96 decibels and with the use of silencers that were under development it could have achieved 95 decibels at 200 feet sadly the aircraft was consigned to history this brings us to the question has the time come to revive it with modern technology but before looking into that let's find out what made the aircraft so unique the name rotodyne in itself carries a couple of clues many of you might be aware of autogyros or gyrocopters these are aircraft that look very much like helicopters but are different in a gyrocopter the rotor blades aren't powered by the engine they are in free rotation that is they rotate as the air which is driven by a separate propeller sweeps past them the rotor blades provide the required lift while the thrust is provided by the propeller unlike fixed-wing aircraft they can fly at very low speeds without stalling while they can't hover in one place they can descend vertically on auto rotation in 1943 a variant of the autogyro called the gyrodyne was patented in a gyrodyne the engine power could be transferred to the normally free rotating rotor blades when required this allowed the aircraft to take off and land vertically and transition to free rotation during cruise mode typically a gyrodyne also has fixed wings which provide some of the left during forward flight thus allowing the rotor to be offloaded and this brings us to the rotodyne just like the gyrodyne its rotor was powered during takeoff and landing but as the name suggests the thrust for moving the rotor came from the tip jets that were mounted on the rotor itself compressed air and fuel mixture was fed to the tip jets by the two thrust producing engines on fixed wings when the tip jets were ignited they spun the rotor to 152 rpm which for a rotor size of 27.4 meter diameter gave enough up thrust to lift 15 000 kilograms it must be remembered that the most energy efficient way of achieving vtol is through large rotor blades a factor called disc loading is often used to estimate the power required for lifting a particular aircraft based on its weight and the size of the rotor blades using disk loading the power required for hovering can be worked out by this very simple formula the power required is equal to the weight of the aircraft times the root of disk loading times 0.5 divided by the density of air to illustrate by the way of an example consider the lilium jet we will look at its existing design and compare it to a hypothetical design of the same aircraft that has large rotor blades instead of several small electric directed fans using the mentioned formula let's evaluate the disk loading and power required for both aircraft the maximum takeoff weight of lilium jet is 640 kilograms it has 36 electric ducted fans each with a diameter of 250 millimeters this gives a disc loading of 3554.64 newton per square meter and the power required comes out to be around 237 kilowatts let's now consider the hypothetical lilium jet with a large rotor blade that equals the wingspan of the aircraft which is 11 meters this gives us a wing loading of just 66 newtons per square meter and the power required comes out to be just 32.2 kilowatts the ratio of the required power of the two aircraft is 7.36 meaning the rotor blade lilium although not as attractive looking as the original would consume seven times less power during veto so the difference in power consumption is clear this begs the question could an aircraft that uses large rotor blades for vtol while using small propellers and fixed wings for forward flight be the solution for urban air mobility the answer is yes if you look around though the evitrol aircraft that have come to the fore none of them have been optimized for retail segment of the flight the philosophy that is applied is that the landing and take-off phase only takes a fraction of the time and therefore most of the electric aircrafts have been optimized for the cruise portion of the flight which will last longer however if you look from the energy consumption point of view for an evital flight that lasts 20 minutes the takeoff and landing portion can consume almost a third of the energy and this is with the assumption that the duration for the takeoff will transition to cruise and from cruise to landing is just 30 seconds each so there is some merit in optimizing for the vertical ascend and descent particularly for short of flights between the city center to the airports furthermore the rotor blade provides much needed safety in case of a power failure it acts like a parachute that will land the aircraft safely by auto rotation other evital aircraft rely on ballistic parachute that have the disadvantage of adding weight and not being able to deploy in time below a certain altitude these design merits led jaunt aviation to bring forward an aircraft that fits the bill for urban air mobility in a way it is the modern incarnation of the rotating albeit on a smaller scale john's reduced rotor operating speed aircraft or rosa is a gyrodyne that builds on carter aviation's compound aircraft who pioneered the slow rotor compound technology compared to the rhotodyne it uses much advanced materials electric propulsion and the use of several innovative patented technologies experts have suggested that it is the safest design to appear so far this aircraft will have a capacity of five people including one pilot it will have a crew speed of 175 miles per hour or 281 kilometers per hour the propulsion system will be composed of four pitch controllable propulsors and one main lifting rotor it will have around 600 kilograms of batteries with a battery energy density of 300 watt hour per kilogram the useful load will be 499 kilograms the range will be 67 mile and a flight endurance time of 180 minutes the wingspan based on estimate is about 15.2 meters let's have a look at the special features of this aircraft other than the large rotor blade one of the first things that you notice is the long and narrow high aspect ratio wings as the takeoff and landing is taken care of by the rotor a large wing area isn't required during cruise so trimmed wings in a sense offset the additional weight of the rotor there are four distributed propulsors that also take care of the opposing rotational torque from the main rotor this means that the tail rotor is no longer required the propulsors not only provide redundancy but also distributed propulsion which has been a common feature of evital aircraft another innovation is what jaunt has termed the level fly technology it allows the mass that holds the rotor to be tilted this achieves two things first it allows the cabin to be easily balanced no matter how many passengers are on board or where they sit and second it achieves thrust vectoring capability in a helicopter the nose may be pitched down for forward flight in the rosa the tilting mast eliminates the need for that thus providing a more level flight best of all the rosa has slowed rotor technology which gives it a range beyond similar compound aircraft during the cruise mode the main rotor is unloaded and auto rotates the wings provide nearly all the lift the speed of rotation of the motor at this point can contribute to significant drag because of transonic speed near the rotor tips the profile drag of a rotor corresponds to the cube of its rotational speed reducing the rotational speed therefore results in a significant reduction of rotor drag allowing for higher aircraft speed since jaund aviation has acquired carter aviation technologies they will utilize their patented multi-pronged approach to slow the motor speed down this includes using higher inertia rotor blades and changing of both the pitch of the blades and transmission system during cruise with a slowed rotor the rosa is estimated to have an l by d ratio of 10 to 12 which is two point times higher than the most efficient helicopter another check that jaunt has up their sleeve eliminates the complexities of conventional rotor blade system that has bearings and pitch links etc they have come up with an entirely new system that uses elastomerics for pitch control which will allow a longer period between inspection thus reducing maintenance cost it is good to see that the gyrodyne an aircraft with such great potential is being revived by electric propulsion joint aviation's rosa at least on paper looks promising enough to meet the stringent regulatory requirements of the aviation agencies it must be said that the compound electric aircraft have a lot of merits that make them ideal for urban air mobility other companies looking to build this type of aircraft can also benefit from using coaxial rotors which will reduce the rotor size and thus decrease not only the footprint but also eliminate the need for complex rotor hub to address lift disk symmetry the tip speed will also be cut down because of smaller blade diameter and thanks to electric propulsion during the cruise mode when the slow rotor speed is designed power can be regenerated by using the motor as a generator and with this the video is finally concluded if you manage to reach this part then give yourself a pat on the back and don't forget to hit the like button thank you for your attention

Channel: Electric Aviation

Views: 94,203

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Id: 5SZhKrAYs6Y

Length: 13min 49sec (829 seconds)

Published: Thu Mar 04 2021