The Green Speed Cup, held every year except for 2016 since 2011, is measure of an airplane’s efficiency, using a formula from the competition’s web site.  “The scoring will be very simple. The aircraft that flew with the best ratio of fuel-consumption per distance and speed will win the competition. The scoring of each competitor will be related to the winner. The winner gets 1000 points for one day.”

According to Robert Adam, one of the organizers of the Cup, “We had a fantastic Green Speed Cup (and rightfully but reasonably prods your editor for not covering the results sooner.)  Luka Znidarsic from LZ Design won with his “front electric sustainer” Ventus glider. He had to close the gap between battery range and the given task range, but he managed with great success.  In our overall statistics of the last 6 cups, he put the e-Genius quite far behind him.”

Ventus sailplane powered by Front Electric Sustainer (FES) designed by winning pilot Luka Znidarsnic

Winning against e-Genius is a formidable accomplishment, since that and Pipistrel’s HY-4 (formerly G4) are acknowledged Green Flight Challenge winners, and both have gone on to stretch the boundaries of economic performance since their 2011 wins.

He marvels at the FES system.  “That little folding propeller system is just fantastic, revolutionary.  With the electric motor, you can within seconds just add a little power to the aircraft and be a glider again seconds later. It apparently enable[s use of] much more energy of the atmosphere in combination with an efficient propulsion, which must finally result in the statistics above.”

Green Speed Cup rules allow soaring when possible to achieve greater “fuel” economy.  A high-performance sailplane such as Ventus can take advantage of that, and use its small motor to speed between thermals or other lift sources.

Second place D39 with akaflieg pilot Holger Massow

The winning combustion class entry saw Holger Massow from the Akaflieg Darmstadt defend his championship from the last cup (2015) in the school’s D-39, a low-wing motorglider.  A Stemme S12 crew, flying for the first time in the event, “improved a lot throughout the competition.”

Scoring showed each craft’s performance relative to a Prius, the common measure of efficiency these days, saw the winning Ventus as 26 times more fuel efficient than the Prius.  Even though hobbled by technical issues, the e-Genius outdid the reference Prius by 6.28 times.  Since it’s a two-seat airplane, it might have counted as being 12.56 times more efficient by Green Flight Challenge rules.  All competitors averaged 2.55 times the fuel efficiency of a Prius, most making better speed in the process.

Total scores for all competitors in the 2017 Green Speed Cup.  See the Green Speed Cup’s web site for details about scoring and the theories that help achieve high scores

It would have been exciting to see more electric craft competing.  Robert reports, “Unfortunately we’ve lost some quite interesting competitors, most of them due to technical issues / permits. Greenelis was unable to compete, the e-Genius had a genset failure some 70 percent down the way to the competition and returned home on batteries on a two-day trip. The Risen ultralight was unable [to compete] due to paperwork.

“We are motivated to see all of them, and even more electric aircraft in the upcoming Cup 2018.  There is time for many potential entrants to get motivated.  The seventh Green Speed Cup will be held June 8th through 10th, 2018 in Strausberg, just east of Berlin.

See all photos from this year’s event here, and pictures from all Cups here.

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A “novel” manganese and sodium-ion-based material might be a contender for the more universal lithium-ion batteries that power our mobile devices and make us mobile in electric vehicles.  Developed by the University of Texas at Dallas in collaboration with Seoul National University, the new material is said to offer “a potentially lower-cost, more ecofriendly option to fuel next-generation devices and electric cars.”

Worldwide distribution of lithium, often in countries at odds with US interests

Dr. Kyeongjae Cho, professor of materials science and engineering in the Erik Jonsson School of Engineering and Computer Science, thinks battery cost is a “substantial issue.”  It may become more of one with electric vehicle production growing from the existing global electric car stock of two million vehicles in 2016 to a projected nine-to-20 million (as reported by the International Energy Agency) by 2020 and between 40 and 70 million by 2025.  This rapid growth will put an added burden on finding and extracting lithium, since the mineral exists in relatively small amounts in sometimes isolated places.

Correction added July 21: More common, “Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels.”  (Wikipedia, which would have corrected your editor just as alert reader Howard Handelman did:

Regardless of cost and ease of extraction (from seawater in some cases), sodium has the drawback of being 20-percent less energy dense than lithium.  This means 20-percent lower energy output or 20-percent less run time on an electronic device, which might be a deal breaker in many applications.

Dr. Cho takes an Edison-like approach to sorting out a solution to this shortcoming.  He questioned, “We used our previous experience and thought about these issues — how can we combine these ideas to come up with something new to solve the problem?”

The research team’s sodium-ion design, which retains the high energy density of a lithium-ion cathode, replaces most of the lithium atoms (green) with sodium (yellow). The layered structure of the new material also incorporates manganese (purple) and oxygen (red).

The research team explains business as usual in a conventional lithium-ion cell: “A battery consists of a positive electrode or cathode; a negative electrode, or anode; and an electrolyte in between. In a standard lithium-ion battery, the cathode is made of lithium, cobalt, nickel, and oxygen, while the anode is made of graphite, a type of carbon. When the battery charges, lithium ions move through the electrolyte to the anode and attach to the carbon. During discharge, the lithium ions move back to the cathode and provide electric energy to run devices.”

Dr. Cho noted the difficulty in previous attempts to substitute manganese oxide in such batteries.  “There was great hope several years ago in using manganese oxide in lithium-ion battery cathodes to increase capacity, but unfortunately, that combination becomes unstable.”

In the team’s new design, sodium replaces most of the lithium in the cathode and manganese replaces the more expensive cobalt and nickel.  Dr. Cho thinks the sodium-ion material is more stable than lithium, but retains its high energy capacity.  He believes it’s scalable, enabling its use in commercial-sized production.

The team used “rational material design” for their studies, turning first to computer simulations to find promising atom configurations before making and testing the material in the laboratory.  Dr. Cho thinks the approach is as important as the material.

“When Thomas Edison was trying to develop a light bulb, he tried thousands of different materials for the filament to see which ones worked. To solve very important engineering problems in society today, we need to develop lots of new materials — battery materials, pollution control materials and others. Edison was perfecting one item — the light bulb — but we have so many more technological needs. We don’t have time to keep trying to accidentally find the solution.”

The team published a paper about the new material in the journal Advanced Materials.

Co-authors of the study are lead author and graduate student Duho Kim and Dr. Maenghyo Cho, both at Seoul National University in Korea. The research was funded by the National Research Foundation of Korea and the Ministry of Trade, Industry and Energy of Korea.

Certainly a battery that is cheaper is desirable, but it remains to be seen whether the 20-percent differential in energy density can be overcome.  As always, further research will help sort that out.

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We’re looking forward to seeing progress in electric aircraft, and this year may be an opportunity to see real breakthroughs.

Two from Pipistrel

Besides its regular lineup of high-quality aircraft, Pipistel will have two Alpha Electro trainers on display in their display area.  This is the first time these aircraft will be seen in America, and they’ll be at the right of AirVenture’s main entrance gate in sites 86 and 87.

Right where they were last year – inside the main gate and to the right

According to Pipistrel, the CAFE Foundation’s Electric Aircraft Symposium will feature,“The General Distributor of Pipistrel for USA, Mr. Michael Coates, [who] will speak about certification and Mr. Paolo Romagnolli, Pipistrel’s R&D Flight Test Engineer, [who] will speak about flight testing electric aircraft.

In the Ultralight Area

Mark Beierle will display and fly Bravo, Richard Steeves’ e-Gull.  This red, white and blue gem features a power system made from Zero Motorcycle components and boasts an impressive rate of climb and exceptional short field capabilities.

Richard Steeves flying his e-Gull Bravo from his home field in Wisconsin

Another ultralight, the EMG-6 developed over the last few years by Brian Carpenter of Rainbow Aviation/Adventure Aircraft, will show off the REX 30 MGM-Compro motor from the Czech Republic.  The units, with their matching controllers, power dozen of different types of aircraft in Europe, from paramotors to Light Sport Aircraft.  This should be a good matchup with Brian’s design.

Brian Carpenter flying EMG-6 with Plettenberg sustainer motor. MGM-Compro will allow self-launches

Personal Sport Aircraft

A little heavier item, the Merlin Personal Sport Aircraft (PSA) will be on display, and Don Lineback promised your editor that his electric motor and battery packs will be on display alongside.  Think of PSAs as being a single-seat LSA, with similar operating and regulatory simplicity.  Chip Erwin’s company, Aeromarine LSA, also makes the Zigolo ultralight, which has been electrically powered.

Merlin PSA will be powered electrically soon, according to Chip Erwin

Work Horses on Land in the Air

WorkHorse will display their SureFly hybrid two-seat helicopter, designed to be easy to fly and easy on the environment.  It shares a great deal of technology with the firm’s stepvan and W-15 Pickup.  Working with United Parcel Service (UPS), they have a drone that can deliver packages from the stepvan, extending the hybrid van’s outreach without using extra fuel.

WorkHorse Surefly hybrid helicopter and W-15 pickup

Embry Riddle Brings It

Embry Riddle Aeronautical University will stage the popular drone racing competition daily between 3:00 and 5:00 p. m.  According to their announcement, “Embry-Riddle Aeronautical University (ERAU) will hold a sUAS  (small Unmanned Aerospace System) Challenge during AirVenture July 20-26. The event will take place inside the netted Experimental Aircraft Association (EAA) Drone Cage … daily using quadcopters supplied by Hobbico and Multicopter Warehouse. The event is open to the public, ages 10 and older, on a first-come first-served basis and is limited to 15 participants per day. Each day will be treated as its own competition. Participants may register for the competition prior to the event by returning a completed registration form via email to thirtyad@erau.edu, or the day of the event at the Embry-Riddle Experience display spanning booths 49, 50, 59, 60 and 61 at Air Venture. EAA will award daily prizes and trophies to the top finisher.”

Embry Riddle’s  innovations in electric flight go further.  Turn to Beth Stanton’s article in the May, 2017 Sport Aviation, “Turning No into Yes,” for an examination of ERAU’s philosophy and exciting outcomes.  The University’s Eagle Flight Research Center’s products include a collaboration with Eric Lindbergh, Charles Lindbergh’s grandson, to create a clean and quiet e-Spirit of St. Louis; work with a Hybrid Electric Aircraft Consortium to craft motors for a nine-passenger hybrid electric turboprop airplane; the Heurobotic UAS VTOL drone; an on-demand aerial vehicle that could replace a car, and a Navion converted to simplified fly-by-wire control that could be applied to general aviation craft.

How many of these innovations will be on display at Oshkosh remains to be seen, but ERAU always has their best and brightest on the field.

SolarShip, Zenith Aircraft to Merge Talents

SolarShip, a Canadian airship maker, is teaming with Zenair to combine their solar-powered inflatable with a Zenair CH-750 STOL aircraft.  According to the partners, “This new aircraft will provide extreme short take-off and landing (XSTOL) capability enabling pilots to take-off in areas without runways. The aircraft is recharged by either a battery swap or electric vehicle rechargers. It will not use any fossil fuel and will be available as a bush plane, float or amphibious [vehicle].”

We hope they’re able to have at least a representation of this product on display.

We hope to see displays from Israel’s EViaton, Randall Fishman’s Electra-FlyerBye Aerospace‘s Sunflyer, Joby AviationPhoenix Air USA, and maybe even the elusive Zee Aero.  Apologies to anyone we’ve left out, but we’ll report on things from Oshkosh or shortly after returning home.

Hope to see you there!

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Zunum is a startup electric airliner firm, helmed by former leaders in aerospace, electronics and software companies.  It’s no surprise, then, to see their design and manufacturing efforts following a path that blends those disciplines.

Aviation Week reports Zunum just received an $800,000 matching grant from Washington State’s Clean Energy Fund, “its size proportionate to funding already raised from Boeing HorizonX and JetBlue Technology Ventures.”  It’s also the second largest of five such awards.  Zunum CEO Ashish Kumar describes the grant as, “a significant amount, a significant endorsement and a significant investment at a national level in electric aviation” that “supplements funds from out-of-state sources and will go toward prototype building.”

Zunum presses forward on an aggressive schedule, with plans to certify its 10-to-19-seat hybrid electric regional airliners “in the early 2020s.”  Founder and Chief Aero Engineer Matt Knapp describes the organization as “mostly a propulsion company with some aircraft development on the side.”  Zunum will develop its power system through a series of version, much like software, with updates released “every six months of so as technology matures.”

Considering that light aircraft go through tough regulatory oversight to manage even simple modifications to existing systems, Zunum is taking a bold step to reconfigure not only the powerplants, but the process for upgrading them incrementally.  As with various bus architectures, Zunum’s propulsion system will allow components to be upgraded over time, as improved motors, batteries, and electronics become available.  Such changes could enable expanding range from 700 nautical miles (805 statute miles) at the launch of the first airplanes to 1,000 nm (1,150 sm) by 2030.

Waleed Said, Chief Technology Officer, led development of the power electronics and control systems for the Boeing 787 and Lockheed Martin F-35.  He will start with Zunum by analyzing assumptions already made in the design of propulsion architecture.  Recent “help wanted” notes on the company web site indicate the need for a Lead Electric Motor Design Engineer, a Lead Power Electronics Design Engineer, and a Lead Power Systems Design Engineer.  These and other hires in aircraft configuration and performance and fan development would grow the current work force from 10 to 20 or 25.  That may seem small, but many wildly successful companies started in garages with a few entrepreneurs.

Ashish Kumar has a goal of having the “copper bird,” a full-scale ground test rig for the hybrid-electric powertrain, running by year’s end.  Then, within the next year, he anticipates having a flying testbed on an existing twin-turboprop aircraft “that will be modified in stages to demonstrate the hybrid-electric propulsion system.”  This development process is similar to what NASA has done with the X-57 Maxwell project, ground testing an off-the-shelf motor from Pipistrel to prepare for a next-step flight article.

Yohan Lin prepares Pipistrel motor on NASA AirVolt test stand – roughly equivalent to “copper bird” Zunum is developing

With the goal of producing a “family of regional airliners… optimized for shorter ranges than today’s turbine-powered aircraft, and therefore suited to electric propulsion,” Zunum plans to work with an airframe builder for the actual final aircraft, while it works on powerplant development.

Opting for the simplicity of natural laminar flow to reduce drag and energy consumption, Zunum will craft its copper bird starting point with the same dimensions as the projected final design, but with heavier, available motors.  These will power ducted fans on both the ground and flight test versions.  Kumar’s approach is to take the hardware from tests, through several iterations, until the system is ready for certification and production.  In his words, “We will have aggressively matured the system.”

Zunum features show exciting possibilities

To keep initial costs low, the firms will use an off-the-shelf turbine, possibly used, as a range extender.  Zunum will work with suppliers to improve on the early baselines.  One desirable feature, quick start capabilities, could allow shutdowns in flight, with rapid restarts as needed.

As might be expected, Zunum will work closely with regulators to meet reserve requirements, first with the requisite fuel supply for the range extender, but finally with a third battery pack to meet the 45 minute reserve.

If the group is able to meet its schedule, find an airframe supplier to mate an airworthy design with their hybrid power system, and maintain good relationship s with regulators, this new company may well see its ambitions fulfilled.  Certainly returning the use of regional airports and making airline flight less stressful will be a welcome re-introduction to the economy.  We wish them luck.

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Geely Looks Skyward, Buys Terrafugia

Geely is a huge enterprise, and while not the largest maker of electric cars in China, sold 766,000 gas and electric vehicles in 2016, growing 50 percent over the previous year.  Its profits grew 126 percent last year, primarily due to sports utility vehicle (SUV) sales.  As EV Obsession reports: “The 351,861 electric car sales registered in China during 2016 represent approximately 46% of ALL plug-ins sold worldwide this year, with Chinese carmakers responsible for 43% of all EV production in 2016.”

Geely, surprisingly, owns Lotus, Malaysia’s Proton Motors, the firm that makes London’s iconic taxis, and Volvo.  Volvo just announced that all its cars will be electric or hybrid starting in 2019.  Fortune reports that the company has become highly profitable, with 2016 net returns doubling to 5.1 billion yuan ($741 million), and possibly rising to 7 billion yuan in 2017.

What is a successful company to do with all that money?  The South China Morning Post reports on one option.  Geely announced the purchase of Terrafugia, makers of a flying car (or more properly, a roadable aircraft) called the Transition.  Terrafugia is currently accepting US$10,000 deposits for prospective buyers to reserve a spot in line to purchase the vehicle, with the first deliveries expected in three years’ time and at an estimated price tag of US$279,000.”  This might be in response to a monster Geely and other Chinese auto manufacturers have created.

Terrafugia has flown at Oshkosh’s AirVenture in 2013 and 2015, showing off the plane’s folding wings that help transform it into a roadable vehicle.  On its Rotax engine, the airplane has a claimed cruising range of 400 miles and a top speed of 100 mph.  In roadable form, it can reputedly maintain highway speeds.  It is equipped with a full-vehicle parachute and “advanced autonomous flight technologies such as automatic terrain avoidance,” according to the Post.

Even though it had raised $5.82 million in five funding rounds, deliveries were tentative and “Experts cautioned that it could take an additional 10 to 20 years for flying cars to hit the roads in Asia, sparing commuters of traffic jam woes.”  Terrafugia pilots will find the same issues that faced Molt Taylor’s customers in the early 1950’s when they tried to buy an Aerocar.  Your editor interviewed Molt several times and he explained that one deterrent to flying car ownership was the nine licenses required to drive and fly his machine.  Terrafugia may have reduced that to eight, since the wings fold.  Molt’s wings took about 20 to 30 minutes to detach and needed a trailer for towing.  The trailer required a separate license.

Terrafugia is certainly not without detractors, though.  Jalopnik notes a long history of promised deliveries, extended timelines, and expanded prices.  The infusion of cash from Geely should allow honoring deposits on the $25 million of reserved backlog and moving forward with development of the VTOL TFX.  The company’s 2013 video shows the premise and the promise of the machine.

The TFX might be a heavy lift, needing a megawatt of battery power to achieve VTOL flight.  That’s about 10 Tesla P100 energy storage units.  At currently reported costs to Tesla, each pack might be as low as $14,500, or $145,000 for the total Terrafugia.  Of course, MSRP sticker prices will be higher to consumers.  The fiscal weight is significant, but the physical load is even more so for a vertical takeoff machine.  Depending on the source, a single Tesla 100kWh battery pack weighs 1,177 to 1,382 pounds.  Since Terrafugia mentions hybrid power as part of the specification, a smaller battery pack will probably be carried.

It will be interesting to see if generous backing can rescue the roadable aircraft.  Geely’s purchase of Volvo saved that struggling car maker, and has put some attractive models on the road.  Note that Volvo just announced that it will build only electric or hybrid vehicles from 2019 on.  It’s good to have a far-sighted backer in your corner.

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Two Multi-Rotors Half a World Apart

New Atlas (formerly Gizmag) alerted your editor to this web site, which in turn features over a score of YouTube videos on this fascinating project in Sweden.  Axel Borg has created, as promised by the web site, an Amazing DIY Project, flying around a hilly woodland on the power of 76 electric motors.

Undaunted by Fuel Fumes or Crashes

More amazing, perhaps, he tried this configuration a year ago with eight internal combustion engines (extremely noisy), but managed to crash that.  Resisting the fear that would instill in queasier souls (your editor, for instance), Axel made four tubular rings, within each of which is mounted a set of 19 motors.  The four rings surround the pilot’s seat, under which are mounted four battery packs – each one supplying a set of motors with power.

Axel has apparently done a good job of managing the control of the machine, showing in several videos his ability to maneuver in roll, pitch and yaw, and describing how he’s programmed proportional and integral (PI) settings in the controllers to a point where he’s pleased with the results.  All the flights so far, and for the immediate future, are purposely kept at a low level.  Axel reports, “I’m not flying higher since I do not believe in reincarnation.”

A great deal of the control comes from the FC 5x KK 2.1 running stock 1.6 firmware.  This multi-rotor control board is a compact gem that sells at commodity prices – around $13 on sale at Hobby King.  It takes in signals from the on-board gyro and uses that data to control the electronic speed controllers that in turn control each motor.  The board can be programmed at a fine level as noted above.

The 76 motors are Turnigy Multistar Elite 5010, 274 Kv units.  Hobby King, apparently a favorite of Axel’s, sells these for $60.96 each.  The 274 kV is a velocity constant indicating the motor turns at 274 rpm for every volt applied – the high speed at maximum voltage making for a buzzy flight experience.  Axel doesn’t identify the carbon-fiber propellers in his YouTube notes.  Each outrunner must produce at least 4.69 pounds of thrust to hold the chAIR in level flight, and a bit more to make it climb.

Each motor is connected to an Afro 20-Amp, HV (high voltage) electronic speed controller (ESC).  Axel fitted a 63 Volt, 330 uF low ESR capacitor to each ESC “to handle the long current path from [the] battery to the ESC.”  Batteries are split into four packs of 20 each and feed the 19 motors per ring.

Overall control flows from five Turnigy TGY-i6S Digital Proportional Radio Control Systems.  These radio control units are extremely sophisticated for their $57.65 price.  Most components for this build came from Hobby King, allowing a total cost around $10,000.

Certainly, such low costs allow experimenters to explore less-likely areas of flight.  That control can emulate industrial PID (proportional, integral, derivative) process and environmental controllers for such low prices and at such low weights allows double and triple redundancy without breaking the bank.  Such controls could make all our aircraft safer, with perhaps control limits that would prevent dangerous maneuvers or overstressing structures.  Some ready-to-fly radio control models come with a form of anti-crash technology, preventing stalls or inadvertent descent into the ground.

You can see Axel’s build in this video.  Other early videos show the construction of the IC-powered version and its eventual demise.

A Korean Counterpart

An unidentified South Korean flies his 12-rotor machine, much like an inverted eHang 184, with larger motors and initially in a yard overhung by threatening wires.  Later flights take place in a more bucolic setting and show good control of this compact machine in all axes.

The one plus factor on this machine is the placement of rotors above the cockpit, although the lower blades could threaten the pilot’s safety.  This is still better than the potential for bodily harm from fragmenting rotor blades on so many multi-rotors.

Regardless, the model aircraft world seems to be melding into the real airplane world, with potentially widespread experimentation and possibly successful home-made commuter machines as a result.

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ONERA’s mission statement for its AMPERE (Avion à Motorisation réPartie Électrique de Recherche Expérimentale) electric aircraft is fairly straightforward.  “AMPERE is a demonstrator of a regional airplane with electric propulsion distributed, allowing to transport from 4 to 6 people over 500 [kilometers – 310 miles] in 2 hours.  The objective of the AMPERE project is to bring to maturity the technology of distributed electric propulsion in order to transfer it to the industry.”  ONERA, the Office National d’Etudes et de Recherches Aérospatiales (National Office for the Study and Research of Aerospace) is the French equivalent of NASA.

ONERA showed a one-fifth-scale model of AMPERE at the Paris Air Show last week, with spokesman and designer Jean Hermetz holding forth on the plane’s features.  Pardon that the video is in French, but the images are universal.  Note the wind tunnel tests at 1:45, showing attached flow over the wing segment on which the electric ducted fans are turning.

The idea has been floating around ONERA for some time, with a low-wing, motors-on-trailing-edge approach and the high-wing, motors on leading edge model shown at Paris.  ONERA promotes the following advantages for the latter configuration:

  • The motors’ positions reduce loss of energy related to friction, through ingestion of the boundary layer.
  • Take-offs and landings are shorter because the motors blow air over a good portion of the upper wing surface, increasing lift at low speeds.
  • Motors can participate in the piloting of the airplane, with differential thrust effecting movement or stabilization of the airplane.
  • AMPERE does not release pollutants during operation.
  • Flight safety is improved “through the sharing of functions.”

ONERA AMPERE as shown at Paris Air Show has 32 electric motors driving ducted fans

Wind tunnel tests at Lille, France, have verified the numerical design of the motor integration for distributed propulsion and its wing blowing effect.  It has also validated predicted aerodynamic performance calculations.  Jean Hermetz reports, “The first feedback is convincing: the expected level of performance is there.”

AMPERE 1/5-scale model in Lille 2 wind tunnel validating design concepts

Power will come from fuel cells developed in partnership with Office of the Commissioner of Atomic and Renewable Energy.  Eight fuel cells provide power to the 32 motors, four motors per fuel cell.  Each motor, in turn, drives an electric ducted fan.  (This last pair of sentences was added on July 3 for clarity.  Thank you to Eric Raymond for the suggested change.)

A paper by Hermetz, Michael Ridel, and Carsten Döll explicates the technical challenges involved for energy storage.  “The different scenarios evaluated through the multi-disciplinary approach show that the Polymer Exchange Membrane hydrogen Fuel Cell (PEMFC) concept is the more promising solution for the considered TLAR (top level aircraft requirements) for providing the electric power (both for propulsion and systems), with the help of a battery pack for instantaneous power demands.”

As batteries improve, the craft could grow from six seats to 50, and range will increase to be competitive with smaller Boeings and Airbuses.

AMPERE in low-wing, trailing-edge-mounted motor configuration

Command and control will take place, “through the association of multi-motors and control surfaces,” according to ONERA’s designers.  The airplane’s modular architecture and in-flight reconfiguration capabilities will allow the overall electric propulsion system to fly with the least drag for and greatest response to control inputs.  ONERA has developed a digital flight simulator to enable future pilots to take advantage of the distributed thrust and to coordinate the motors and control surfaces in new ways.  Eventually, ONERA hopes to do away with control surfaces altogether, using differential thrust to manage all flight maneuvers.

With innovative ideas flooding the next generation of creative aerial solutions, we can all be buoyed by the prospects of many of these new concepts reaching commercial reality.

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Airspace X MOBi Wants to Take Back Our Lives

Airspace X decries the thought that “Traffic is taking over our lives.”  It lists three concerns: the 42 hours urban commuters sit in traffic per year; the 1.9 billion gallons of fuel wasted due to road congestion; and the $1,400 wasted per driver per year due to traffic.  Its solution, an electrically-powered four-seat commuter vehicle called MOBI.  The e-VTOL (electric vertical takeoff and landing) machine, introduced at the Uber Elevate Summit on April 27, lays claim to being able to fly its passenger at rates equal to an Uber Black ride.

According to NBC News, Uber Black “town car” style trips are usually longer than “standard” rides, in a shortlist of approved vehicles – the Audi Q7, BMW X5, Cadillac XTS, Porsche Panamera, or any Bentley or Rolls Royce that is “black on black” – black exterior with a black leather interior.  Riders pay a high premium, though – $3.55 per mile, compared to the next level, Uber X, at $0.90 per mile.  Your editor has experienced two Uber rides in Priuses at much lower prices, but significantly nicer than his daily driver, a 1995 Subaru with 273,000 miles on it.  Luxury truly is a comparative thing.

Airspace X is an outgrowth of Detroit Aircraft Corp. and is an air mobility company “that will deliver affordable, on-demand air travel, connecting cities, suburbs, and surrounding airports around the world.  Detroit has grown from a company that tried to bring aircraft manufacturing to the city, developed a series of drones for first responders and commercial users, and has now brought forth a different aerial mobility (MOBi) solution.

Airspace X MOBi allows passengers to remain on the level while pivoting wing and propellers enable VTOL flight

Jon Rimanelli, founder and CEO of AirspaceX, explains,“With MOBi, we will deliver a new experience in air transit and point-to-point air mobility. It will be a clean, quiet, stabilized flight experience that is accessible and affordable to the masses.”

Somewhat like the Airbus Pop.Up!, MOBi consists of three modules: flight, payload, and ground.  Like Pop.Up!, MOBi’s passengers ride in an unpowered payload module, which can either ride around on a separately powered ground module when fighting it out with city traffic.  An electric motor-powered flight module twirls four propellers to allow VTOL flight – but notice the singular power plant.  It will have to be powerful enough to lift the weight of the flight vehicle including the 400 kilogram (880 pound) payload.

Like Airbus Pop,Up! MOBi consists of three modules

The company claims the single electric motor will produce zero carbon emissions and be “significantly quieter” than helicopters and airplanes.  That will doubtless require the four propellers to turn at reasonably low rpms.

Passengers will ride in a level cabin, with vertical takeoffs and landings accomplished by pivoting the wing and propellers to a vertical position.  Transitions to high-speed horizontal flight take place when the wing and propellers pivot to become parallel with the cabin.

Straight-line flight, absence of gridlock enable truly rapid transit

By taking advantage of uncluttered skyways and straight-line flight, MOBi can cut an hour off that for an equivalent ground trip. People who can afford an Uber Black ride tend to value their time highly, and will see such trips as real bargains.  At the rates promised, even those of more humble means might take an occasional sky taxi.

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Full-Spectrum Solar-Generated Hydrogen

Osaka University researchers have created a new material based on gold and black phosphorus to produce clean hydrogen fuel using the full spectrum of sunlight.  Most solar apparatus used in “water splitting” rely on materials such as titanium dioxide.  These are limited to obtaining energy from the ultraviolet (UV) part of the solar spectrum, however.  The rest of the spectrum is wasted.

Osaka’s team “developed a material to harvest a broader spectrum of sunlight,” using a three-part composite.  The different parts maximize absorption of light and enhance the efficiency of the unit for water splitting.  The core, a “traditional” semiconductor of lanthanum titanium oxide (LTO) is coated with tiny nanoparticle specks of gold.  The gold-covered LTO is then mixed with ultrathin sheets of black phosphorus (BP), which acts as a light absorber.

LTO, BP and gold combine to produce greater excitation on solar-collecting surface. Electron microscope images of visible-NIR (near infrared) light responsive photocatalyst composed with black phosphorous (BP), lanthanum titanate (LA2Ti2O7, LTO), and gold nanoparticles (Au)

Bonding the gold-coated LTO to the BP layer makes a serendipitous combination.  Team leader Tetsuro Majima says. “BP is a wonderful material for solar applications because we can tune the frequency of light just by varying its thickness, from ultrathin to bulk. This allows our new material to absorb visible and even near-infrared light, which we could never achieve with LTO alone.”

The report continues, “By absorbing this broad sweep of energy, BP is stimulated to release electrons, which are then conducted to the gold nanoparticles coating the LTO. Gold nanoparticles also absorb visible light, causing some of its own electrons to be jolted out. The free electrons in both BP and gold nanoparticles are then transferred into the LTO semiconductor, where they act as an electric current for water splitting.”

Absorbing a broader spectrum of light and conducting electrons more efficiently, the “unique interface” between BP and LTO results in a material 60 times more active than LTO along.

Majima says, “By efficiently harvesting solar energy to generate clean fuel, this material could help to clean up the environment.  Moreover, we hope our study of the mechanism will spur new advances in photocatalyst technology.”

The abstract for their paper can be found on the web site for the Angewandte Chemie International Edition, 2017.
Abstract: Efficient utilization of solar energy is a high-priority target and the search for suitable materials as photocatalysts that not only can harvest the broad wavelength of solar light, from UV to near-infrared (NIR) region, but also can achieve high and efficient solar-to-hydrogen conversion is one of the most challenging missions.Herein, using Au/La2Ti2O7 (BP-Au/LTO) sensitized with black phosphorus (BP), a broadband solar response photocatalyst was designed and used as efficient photocatalyst for H2 production. The optimum H2 production rates of BP-Au/LTO were about 0.74 and 0.30 mmol g@1h@1 at wavelengths longer than 420 nm and 780 nm, respectively. The broad absorption of BP and plasmonic Au contribute to the enhanced photocatalytic activity in the visible and NIR light regions.Time-resolved diffuse reflectance spectroscopy revealed efficient interfacial electron transfer from excited BP and Au to LTO.  which is in accordance with the observed high photoactivities.

Mingshan Zhu, Xiaoyan Cai, Mamoru Fujitsuka, Junying Zhang, Tetsuro Majima; “Au/La2Ti2O7 Nanostructures Sensitized with Black Phosphorus for Plasmon-Enhanced Photocatalytic Hydrogen Production in Visible and Near-Infrared Light,” Angewandte Chemie International Edition, 2017

Their findings would seem to have implications for all solar collectors, with greater efficiency possible for solar cells.

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Dubai, already having penned a similar agreement with China’s eHang, will start test runs of autonomous air taxis in 2017 with the Volocopter.

Volocopter’s Eventful Year

Volocopter has had an eventful year, introducing its latest model, the 2X, at this year’s Friedrichshafen Aero E-Flight Expo and opening its new corporate headquarters.  Now, it looks forward to demonstrating its craft in regular service.  e-Volo writes, “Our vision becomes reality: Dubai’s government “Roads and Transport Authority” (RTA) has signed an agreement with us regarding the regular test mode of Autonomous Air Taxis (AAT) in the emirate. The test will start in the fourth quarter of 2017, and the project has been scheduled to run for five years.”

The Volocopter 2X, according to its makers, is simply foolproof, having 100 microprocessors and a large number of sensors helping maintain vehicle stability, even in turbulence.  Volocopter has demonstrated hands-free flight on several occasions.

Stability is part of its safety factor, and 18 rotors with compensating mechanisms ensure that the Volocopter can maintain flight even with several motors out of commission.  Nine battery packs and controllers allow continued operation even with the loss of one.  If all else fails, a ballistic parachute (“for incorrigible pessimists”) enables the occupants’ descent “to the ground, very gently, still securely seated in the aircraft.”

Operational and safety factors for Volocopter 2X

Simplicity and safety complement the green operation its makers claim for Volocopter, looking beyond its current state of pollution-free flight to improved batteries, longer range and increased utility.  All these factors will get a good workout in the skies between skyscrapers.  E-Volo looks forward to the challenge.  “Now this technology will experience further testing in Dubai under extreme climatic conditions. We see Dubai as the pioneer for a huge evolving market and are convinced that many other metropolitan areas will follow.”

The Verge notes that Dubai is, “A testing ground for some of the transportation world’s more futuristic and outlandish ideas.”  Tests start in the fourth quarter of 2017, and are scheduled to last five years.  Alexander Zosel, co-founder of Volocopter, said, “We are very grateful and proud that the RTA has selected us as their partner after rigorous testing,” adding that his company’s “stringent safety standards” were one of the reasons for that selection.

Volocopter’s prototype VC200 took its first crewed flight last year. And at Europe’s largest general aviation trade fair earlier this year, the company revealed its first production model: the 2X. It has a maximum range of 17 miles when flying at a speed of 43 mph. Its maximum flight time is 27 minutes at an optimal cruise speed of 31 mph, but if range were no concern, the 2X can fly at a maximum speed of 62 mph.

Volocopter 2X and the eHang 184

The Verge elaborated that, “Volocopter won’t be the only flying taxi service buzzing through Dubai’s airspace. RTA also recently struck a deal with the Chinese drone company Ehang to test its single-person quadcopter as a transit alternative. Uber is also in talks with the emirate city to publicly demonstrate its own flying taxi service in 2020. And if flying through the air in an autonomous drone isn’t your bag, perhaps you’d be more interested in tube-based travel: Dubai is working with LA-based startup Hyperloop One to build the world’s first passenger-ready hyperloop.”

The English Publication, The Engineer, gives a few technical points.  “Designed and built in Germany, the Volocopter can fly autonomously using 18 individual rotors powered by nine swappable batteries. The aircraft has a top speed of 100km/h [62 mph] and maximum flight time of around 30 minutes.”  If all goes well, RTA looks forward to seeing a quarter of all trips in Dubai carried out by autonomous transport by 2030.

His Excellency Mattar Al Tayer, Director-General and Chairman of the Board of Executive Directors of RTA, explains RTA’s role in the tests. “The RTA is working with the Dubai Civil Aviation Authority to develop the legislative and operational guidelines, define specifications and standards applicable to operators in the emirate such that these legislations will be ready. It is noteworthy that the operational and legislative structures will be the first of their kind worldwide.”

Earlier this year, Chinese company eHang signed an agreement with the RTA to begin testing their single-seat 184 as an on-call aerial taxi.  Since the two vehicles carry different payloads and have similar vertical takeoff and landing capabilities, comparisons will doubtless be made, but both will have to demonstrate reliable operation under the Dubai sun.

And on the Waterfront?

Kittyhawk Aero recently demonstrated its Flyer for an appreciative San Francisco audience.  It made your editor wonder if Kittyhawk could provide low-altitude commutes to one’s private island four kilometers from the central city, while e-Volo and eHang stage a friendly competition above.  The “select few” who prosper in this rich city will probably jump on board.  Warning: a real-estate pitch follows – but also provides a glimpse of what it would be like to fly over and through this astounding city.

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