Dante AeroNautical Distributes Power

In a dramatic rendering, Dante AeroNautical shows its DAX-19, a regional airliner that will distribute power along its wings, much like NASA’s X-57 Maxwell.  Dante describes the craft as representing, “The regional electric air travel of the future.”

Dante’ AeroNautical’s 11-motor airliner for intermediate-range missions

(In Dante’s web site, the triangle in place of the conventional “a” is the alchemical symbol for fire, or a clever marketing type’s attempt to draw our attention.)

Helmut Penner, writing in Cockpit magazine, gives us the following: “Typically, small airlines make their aircraft purchases from major manufacturers, including the still-young Spanish low-cost airline Voltea, which operates 14 A319s and 17 Boeing 717s. But now [the company] is aiming for an ambitious project with the Dante AeroNautical, which is also based in Spain. Already in the middle of the next decade, a hybrid aircraft for 19 passengers to be developed will be used for short-haul flights.”

A Small Airline Checks In

Voltea “will work actively with Dante Aeronautical to develop this hybrid-electric aircraft to help reduce CO2 emissions and aircraft noise, the airline said. Voltea and Dante will receive help from the Instituto de Empresa in Spain, ALTRAN in Europe and the University of Sydney and the University of Adelaide in Australia.

Initially to be a hybrid system with a turbine-driven generator powering the 11 propellers, the DAX-19 will move to full-electric power as battery developments permit.  The hybrid system will reduce emissions and fuel consumption by 50 percent over those for a similar fossil-fuel burning system.

Volotea and Dante expect their hybrid aircraft to become commercially available in the middle of the next decade.

Distributed Drives Are Not New

Decades back, Burt Rutan proposed putting multiple small engines on aircraft wings in an interview for a car magazine.  He thought that this would increase overall safety and maybe even obviate the need for control surfaces by providing differential thrust in variable directions.

Wingtip Propellers (WTP) on Stuttgart University’s Icare’ 2 test the promises of control and drag reduction

NASA and its French equivalent ONERA have explored the possibilities with the X-57 Maxwell and the Ampere.  The Israeli Alice has applied the idea to an electric medium-range commuter.  Recently, the Institute of Aircraft Design (IFB) and the Institute of Flight Mechanics and Flight Control (IFR) of the University of Stuttgart have tested a pair of Wingtip Propellers, or WTPs.  “The surface end drives are mounted on detachable and differently configurable pods weighing nine kilos each on the two wing tips and equipped with their own batteries and measuring sensors. The rather inefficient electric propeller drives in relation to the drive offer the possibility of an active yaw control in addition to the rudder function. The motors can be controlled either manually or automatically. From the pilot, the control command can be introduced via a newly installed sidestick.  Alternatively, it is added directly to the rudder input, or optionally the aileron input,” according to the University.

Stuttgart notes that, “Although the performance is low compared to the main engine, the steering effect is enormous. With the propellers at the wingtips, the developers get an additional yaw control in addition to the classic rudder.”  Added to that, a wingtip propeller can work with tip vortices to gain thrust and reduce tip drag.

Batteries and motor in a tube drive wingtip propellers (WTP) on Icare’ 2, entering 23rd year of flight

Stuttgart looks forward to mounting rotatable tip propellers which could add vertical thrust and “relieve the pilot’s workload.”

The University closes its report with this note.  “The solar aircraft icaré has been operating as a test aeroplane of the Faculty of Aerospace Engineering at the University of Stuttgart for more than 20 years. The wing end propulsion project is supported by the technical support of SFL GmbH and the test pilot Werner Scholz.”  Scholz was involved with the construction.

With Alice and the X-57 nearing flight tests and Stuttgart providing ongoing data,  Dante AeroNautical will have a great deal of experience from which to draw.  Look for aircraft taking on a new look in the next few years.

Economic benefits maybe more important.  Dante co-founder Miguel Madinabeitia hopes “to open a ‘new market for door-to-door regional air transport’ with competitive costs structures.

“If we want to make aviation more sustainable, we need to find the sweet spot between ambitious emissions reduction targets and realistic economic propositions,” he adds. “A full electric aircraft is a nice long term goal, but it will have very little impact in the near term if it is just a niche product for wealthy individuals.”


Toni Roth’s C42 Hybrid Range Extender

The Comco Ikarus C42 is a popular ultralight aircraft in Europe, now being tested with a unique hybrid power system.

Anton (Toni) Roth was an early adapter, putting small electric motors on a variety of ultralight aircraft over the past several years.  These have been the lightest of machines powered by Eck/Geiger motors, controllers and batteries.

His latest is a hybrid conversion of the popular C42, two-seat ultralight which normally flies on a Rotax engine, as do most European ultralight craft.  In this case, Roth has mounted a Swiss single-cylinder four-stroke engine behind the pilot’s seats driving a Geiger generator which in turn powers a Geiger HP-55D motor on the nose, delivering up to 73 kilowatts (97 horsepower) and providing a rate of climb of five to six meters per second (584 to 1181 feet per minute) – an impressive performance for small aircraft.

Helvenco engine mounted behind pilots balance major weights near center of balance

The engine, sipping a mere five liters (1.32 U. S. gallons) per hour, enables the generator to deliver a constant 30 kilowatts. At least partly because of its abstemious character, the motor allows long endurance even at ultralight regulated fuel quantities.  Along with an electric variable-pitch propeller that Roth hopes to test soon, the company has a goal of remaining aloft for at least five hours.

Roth and his team tested several different two-stroke and four-stroke engines before settling on the current unit from Swiss engine company Helvenco.  The single-cylinder engine produced at the company in Burgdorf near Bern displaces 250 cc and weighs only 36 kilograms (80 pounds).  The video below is in German, although most of it is highly understandable overall.  Parts of it have the ambient sound of the powerplants in operation, although much of the natural sound is obscured by music such that one expects Shaft to be flying the airplane.  Please, manufacturers, give us actual sounds, not funk.

Comco Ikarus has sold over 1,400 of the CS42 models in all configurations, so the hybrid option may have a significant market, especially in Europe.  It’s lighter than U. S. equivalents, helping its climb and cruise.  Any machine that can carry two at around 100 mph for five hours would definitely find favor with the economy-minded who wish to explore the world outside airport boundaries.


SAS 2019: Dr. Sangita Gupta and ASX

Two years ago, the Airspace X (ASX) MOBi  promised to achieve passenger costs equal to an Uber Black ride.  More importantly, the company promised that it might take back our lives, eliminating the frustration and wasted time lost in traffic gridlock.

We caught up with ASX at this year’s Sustainable Aviation Symposium, held at UC Berkeley.

Dr. Anita Sengupta, co-founder and Chief Product Officer for the firm explained the current outlook for ASX.  Where the MOBi-One (Mobility-One) looked like an offshoot of Airbus’s Pop-Up modular vehicle, it is now close to one of Uber’s concept craft used to guide designers.

Dr. Sengupta’s background as aerospace engineer, rocket scientists and veteran of the space program has led her from deep space back to earth and to more terrestrial flight regimes.  She explains that transition in this short video.

She started her career at Boeing Space and Communications, helping launch vehicles and communications satellites. She went on to 16 years with NASA, “…Where her engineering projects included her PhD research on developing the ion propulsion system for the Dawn Mission (currently in the main asteroid belt), the supersonic parachute that landed the Curiosity rover on Mars, and the Cold Atom Laboratory an atomic physics facility now on board the International Space Station.”

She left NASA to lead the development of the Hyperloop as Senior Vice President of engineering systems at Virgin Hyperloop.  In 2019, she become a co-founder and Chief Product Officer of Airspace Experience Technologies, or ASX (asx.us) in Detroit Michigan.

In 2019 she became a co-founder and chief product officer of Airspace Experience Technologies, or ASX (asx.us) in Detroit, Michigan.  She has adopted many Motor City approaches to MOBi-One.  Her biography in the SAS 2019 program explains, “As an engineering savvy executive and pilot, she is now leading the mobility solutions for smart cities by eliminating congestion and reducing the carbon footprint of air travel.”

MOBi-One at intermediate stage of development. Note propellers above and below tilting wing, where now their line of thrust follows the wing’s chord line. Dual tail lift devices are now in the V-tail at the extreme end of the tail boom

She looks forward to being able to reduce ride costs by lowering the unit cost of vehicles by leveraging Detroit’s ability to mass manufacture vehicles. Because MOBi will fly at low altitudes, a good many problems with things like pressurized cabins will be eliminated.  Aircraft will key off vehicle-to-vehicle (V2V) automotive technology to help with close-in separation.  Noise signatures will be reduced by 20 dB over to maintain neighborhood and flight path acceptance.  These and other technical answers are essential to a thriving future for the new industry.  With various sources predicting a $1.3 trillion market and as many as 200 manufacturers hoping to exploit that market, it will take intelligence and daring to find success.

ASX’s mission gives Detroit its due.  “By offering a eco-friendly, quiet and connected ‘electric vertical takeoff and landing’ (eVTOL) aircraft that leverages the perfect fusion of proven automotive grade innovation and aviation technology, ASX can re-imagine the daily commute and give commuters time back to be more productive.

Passengers waiting to board will find excellent view with seatback video screens if the the view does not please

Bob A. Lutz – Former Vice Chairman for General Motors and a member of the ASX advisory board, reflects this philosophy.  “Detroit and Michigan are strategically positioned to leverage its industrial base to lead in this rapidly emerging market for On Demand Air Mobility”

With the vision and engineering skills people such as Sangita Gupta can provide, these visions have a good chance of becoming realities.


Cambridge’s Artificial Leaf Makes Syngas

Cambridge University researchers have developed a new “artificial leaf” that uses sunlight, carbon dioxide and water to directly generate “syngas,” without releasing additional CO2 into the atmosphere.  As the Cambridge team reported, ‘Syngas is currently made from a mixture of hydrogen and carbon monoxide, and is used to produce a range of commodities, such as fuels, pharmaceuticals, plastics and fertilizers.”

Other “leaves” have been devised, perhaps the most famous being that of Daniel Nocera, formerly at MIT and now at Harvard University.  He was among the first and at the time, most successful, or the leaf producers.  Note the next step he proposes at the end of the short video.

Professor Erwin Reisner from Cambridge’s Department of Chemistry has been working for seven years on achieving Nocera’s desire to directly produce fuel from the elements.  “You may not have heard of syngas itself but every day, you consume products that were created using it. Being able to produce it sustainably would be a critical step in closing the global carbon cycle and establishing a sustainable chemical and fuel industry.”

Pursuing the vision of producing photosynthesis, Reisner and colleague split the process with two light absorbers and a single cobalt catalyst to separately produce oxygen on one side and a mix of carbon monoxide and hydrogen – the ingredients for syngas – on the other.

Architecture of the standalone perovskite–BiVO4 PEC tandem device for bias-free syngas production. Oxygen evolution occurs at the front BiVO4 photoanode with a Co WOC. An inverse-structure perovskite photocathode reduces CO2 and protons to CO and H2 via a CoMTPP molecular catalyst immobilized on a CNT sheet. An embedded copper wire connects the two photoelectrodes in this artificial leaf configuration. FTO, fluorine-doped tin oxide; PCBM, [6,6]-phenyl C61 butyric acid methyl ester; PEIE, polyethylenimine. Andrei et al.

The cobalt catalyst reacts with the materials to produce the oxygen and the syngas ingredients, and apparently works well during periods of low light on rainy or overcast days.  PhD student Virgil Andrei, first author of the paper, explained the importance of this. “This means you are not limited to using this technology just in warm countries, or only operating the process during the summer months. You could use it from dawn until dusk, anywhere in the world.”

Cobalt would be one ingredient of concern, being toxic and moderately difficult to separate from the nickel with which it is often found.  The researchers noted with double exclamation points cobalt’s contradictory application here.  Although it is less expensive than other catalysts such as platinum, it is somewhat difficult to dispose of or to reuse.

Syngas, a mixture of CO and H2, is a crucial intermediate in the industrial production of methanol, higher alcohols, long-chain hydrocarbons, lubricants, waxes and fuels via the Fischer–Tropsch process. … The conventional reforming of methane to syngas relies on fossil fuels to operate at high temperatures and pressures and biomass gasification can introduce contaminants. The solar-driven production of syngas from aqueous CO2 is an ambient conditions and clean alternative process. Although silicon, dye, metal oxide and perovskite photoabsorbers provide enough driving force in tandem devices for bias-free water splitting, very few examples of bias-free photoelectrochemical (PEC) CO2 reduction are known.


Virgil Andrei, first author of the Cambridge research team’s paper in Nature Materials

Owing to the large overpotentials that need to be overcome for a simultaneous CO2 reduction and water oxidation, most of those systems employ up to six photovoltaic (PV) solar cells connected in series or complex nanostructures based on noble metals. Accordingly, a vast library of molecular catalysts that employ earth-abundant metals for CO2 reduction remains underexplored. Such catalysts are known to achieve improved selectivities towards CO production at lower overpotentials—Co porphyrin and phthalocyanin recently demonstrated a selective aqueous CO2 reduction to CO when immobilized onto carbon nanotube (CNT)-based electrodes.

Here we tap into that library of molecular catalysts by using the commercially available cobalt(II) meso-tetrakis(4-methoxyphenyl)porphyrin (CoMTPP), which can be readily immobilized via π−π stacking interactions onto CNT sheets, also known as buckypaper. The composite is employed in electrodes, state-of-the-art perovskite-based photocathodes and perovskite–BiVO4 PEC tandem devices, which couple tunable syngas to O2 production in an aqueous solution.

—Andrei et al.

The Christian Doppler Laboratory for Sustainable SynGas Chemistry in the University’s Department of Chemistry performed the research, which was co-funded by the Austrian government and the Austrian petrochemical company OMV, “which is looking for ways to make its business more sustainable.”

The team hopes to find ways to make the syngas into usable fuels in one step.  Since, according to Reisner, electricity can supply only 25-percent of the total global energy demand, “There is a major demand for liquid fuels to power heavy transport, shipping and aviation sustainably.”

The “gradual” transition from fossil fuel to renewable synfuels

Somewhat discouragingly, the ability of batteries to meet that demand is still unrealized, so we will need to make liquid fuels cleaner and more obtainable in the meantime.  This artificial leaf may be a bridge to the future.


A Glorious Calendar

Eric and Irina Raymond, besides being skilled solar-powered airplane builders, designers, and pilots are also professional photographers.  Their 2020 Solar Flight calendar highlights all those skills and provides historical background for their work.  Besides that – it’s gorgeous.

With a baker’s dozen stunning color photos, and historical black-and-white archival images on the back of each month’s offering, the calendar is a nice blend of modern artistry and the chronicle of an eventful past.  Did you know, for instance, that Eric flew the first solar-powered aircraft across America in 1990 – 23 years before Solar Impulse’s journey?

One episode on Eric’s blog is worthy of attention.  “At my slow flying speed, I often flew in formation with flocks of birds. Nearing the Appalachian Mountains, I flew with the same three black birds two days in a row. They were still following me when I reached the highest part of the mountain range that I needed to cross. I decided the safest thing to do was to fly up through the clouds, so I could fly over the tops of all the clouds and mountains.

I switched on my simple blind flying instruments, but even with my head down, I noticed the three black birds, hovering just above and to the sides of my window. The thicker the cloud, the closer they stayed, but they never left, until we were in the clear again.”

Your editor learned from the calendar that Eric had flown from Munster Airport over the Alps on three days and topped the Matterhorn each day.  Eric has mentioned elsewhere that was a childhood dream achieved.

Eric has a knack for crafting lightweight structures.  Sunseeker 1 had a 45-foot span and a structural weight of 98 pounds.  The 72.8-foot cantilever wing-span Duo has an empty weight of 638 pounds: compare that to a Continental 65-horsepower J3 Cub that weighed 766.5 pounds with a strut-braced 36-foot wing.

The Pitch

It’s fun seeing what Eric and Irina will come up with next. To help support their pioneering efforts, they are selling their calendars.  Judging by the two previous offerings, the $32.50 (plus shipping) they ask for their 19.5 inch by 16 inch is a bargain, filled with images that can be framed.

Your editor has fun explaining the airplane and the flights its made to friends and family.  If nothing else, the Raymonds’ calendar is a great conversation starter.  People are fascinated by the airplane, and the photography.  A common question from friends: how did they take that picture?

The last color image is the Sunseeker Duo in a sunlit sky of towering clouds, looking very much like a Christmas snow-globe.  Maybe next year they can turn that into a real Christmas snow-globe.

(Note: Your editor works on a volunteer basis and has no financial interest in selling the Sunseeker calendar.  It comes, though, with an unsolicited and enthusiastic endorsement from your editor.)


Volocopter’s Short Flight Over the Bay

Volocopter air taxi flies over Singapore’s Marina Bay

Volocopter flew the latest version of its two-seat sky taxi, the 2X, on a two-minute, 1.5-kilometer excursion around and over Singapore’s Marina Bay on October 22.  This short flight, surrounded by massive, futuristic skyscrapers, highlighted the controllability of the small machine and its ability to use minimal infrastructure, taking off from and landing on a simple grass plot.

Florian Reuter, CEO of Volocopter, applauded the flight’s verification of his vision.  “The flight today in Singapore was the most advanced Volocopter flight yet and the piloted flight was as stable as ever. At the same time, we are showcasing a prototype of our full-scale VoloPort Infrastructure, allowing for a realistic demonstration of air taxi boarding and maintenance services. Never before have people been this close to experiencing what Urban Air Mobility in the city of tomorrow will feel like.”

Perfect for commuting on the island, Volocopters would enable transit across the 50-kilometer (31-mile) width and 27-kilometer (17-mile) north-to-south span.  It would make access to the offshore islands an easy trip.  Landing atop Singapore’s tallest buildings would be more taxing than surmounting its highest geographical point, Bukit Timah Hill at 182 meters (597 feet).

The October 22 flight was the last in a series of “demanding test series to verify and validate the ability of Volocopter air taxis to flyover the area.”  Results were signed off by the Ministry of Transport (MOT), the Civil Aviation Authority of Singapore (CAAS), and the Economic Development Board (EDB), who will also oversee future efforts.

Mr. Ho Yuen Sang, Director (Aviation Industry) from CAAS validates that thought. “Since late 2018, the Civil Aviation Authority of Singapore (CAAS) has been working with Volocopter to facilitate this flight in Singapore. The Volocopter team went through a series of stringent evaluations to ensure that all the necessary safety requirements were met before the flight was allowed to take place. By working closely with companies such as Volocopter, we hope to facilitate innovations for beneficial uses whilst ensuring aviation and public safety,”


Singapore’s prototype Voloport includes a 2X on display

Voloports will be an integral part of developing this enterprise.  Florian Reuter, CEO of Volocopter, explains, “There are three major aspects that need to be in place for urban air mobility to become reality: the aircraft, the infrastructure, and the necessary regulation for both. Standing inside the VoloPort makes Urban Air Mobility feel extremely real and demonstrates that air taxi operations are not a faraway future, but very feasible to achieve within the next two to five years. Today marks a fantastic step forward!”

As a sign that Volocopter intends to press on with flight in Singapore, their Voloport prototype on the Float @ Marina Bay opened as part of the ITS (Intelligent Transportation Systems) World Congress this year, and will bring on a full local staff by 2020.

With Volocopter and eHang (flying its board of directors, no less) having made public flights while carrying passengers or a pilot, the impetus to reach production and develop a customer base seems to be burgeoning.  Others are announcing formerly unpublicized test flights, and seem to be edging toward more public demonstrations.  Lilium and Airbus may soon be part of the news cycle, along with Kittyhawk and the contestants in Boeing’s GoFly competition.  We are about to see a jump in public interest.


Lilium Goes Institutional and Aspirational

Lilium has done its marketing homework. They seem to be using a lot of marketing skills to move a potentially revolutionary product most of us have no chance of ever owning.

Selling Lilium’s Benefits

What makes us want things?  What floats our boats?  What makes us stop in our tracks and look in a store window?  What drags people out of their beds at midnight to stand in line for the Blu Ray of the latest Harry Potter film?

Writing technical documentation first for an electronics firm and then for a major engineering design/build company, your editor helped create many proposals, inserting relevant technical data into promotional material and proposals.  Working with one particularly successful marketing manager, your editor learned an important lesson: sell the benefits – not the features of the product or service you are providing.

Technically-minded types usually like to bask in the features of a product – how many horsepower, how much torque, refresh rates, etc.  For most consumers, though, such things are not as interesting as how those features will make his or her life better.  Lilium seems to have caught on to this, and does a respectable job presenting why people might want to take a ride in their machine.  They use a few well-defined points that present what for most people will be compelling reasons.

In their video, the company promotes the time-saving nature of their machine, enabling one to spend more time with one’s family, for instance.  This appeal to traditional values is a well-recognized emotional pull often used to sell products.

Lilium dropping in at a London landing site, a simple platform with welcoming passenger accommodations

Lilium enlists its features, though, to provide reassurance about its product’s safety.  “The emissions-free aircraft, which will be able to complete journeys of up to 300 km in one hour on a single charge, has now been flown at speeds exceeding 100 km/h, in increasingly complex maneuvers.”  The video includes words that even failures have led to improvements and greater safety.

Images are not much about the high-tech vehicle, but of nature and people communing therein.  A soft female voice tells all.  It’s a good, and soothing idealization of what flight in a Lilium may promise.

Getting Real

Lilium is working hard to roll out its machines and implement its minimalist infrastructure.  Speaking of its new production facilities in southern Germany, Daniel Wiegand, co-founder and CEO, said: “Our ambition is to develop a world-class production facility here that will allow us to build critical parts ourselves and then deliver fully-assembled aircraft at the scale of the automotive sector but at the extremely high quality levels required in the aerospace sector.

“Having considered many locations to produce our first Lilium Jets, we felt our location in the heart of Europe was best suited to our needs, given the strength of the local aerospace supply chain.

Lilium engineers working on the machine. Note the modular nature of construction

“Having our production facility co-locate with our headquarters also makes sense at this point in our development, allowing us to maintain the rapid pace at which we are developing the Lilium Jet, from innovation through to engineering and manufacturing.”

Today, Lilium employs more than 350 people at its base in Munich, with more than 150 roles currently available across a range of disciplines. The new production facilities are expected to create up to 500 new jobs between now and 2025.


Honoring John Langford

If one stays with a line of work long enough, one will accomplish mighty things.  That’s certainly true for John Langford, Chief Executive Officer for Aurora Flight Sciences.  His decades-long career, start his decades-long career, starting at Massachusetts Institute of Technology and culminating his company partnering with Boeing, has explored almost every aeronautical discipline.  For this perseverance, he was awarded the 2019 Personal Aircraft Design Academy (PADA) Trophy.

Aurora Flight Sciences’ Chief Technology Officer, Tom Clancy, was on hand at the 2019 Sustainable Aviation Symposium at UC Berkeley to accept the award for Langford.  Clancy has worked with Langford since their MIT days, building and flying several human-powered aircraft, including the 1974 Daedalus.  That aircraft flew the 74 miles from Crete to Sicily over the Mediterranean Sea, still the human-powered distance record.  He and Langford went on to design, build, and fly an astonishing range of aircraft.

Putting solar cells on Daedalus gave them a pilotless airplane that could stay up for extended periods.    This led to larger machines with even greater endurance.  Here we get to see Dr. Langford and Clancy in the same video.

Aurora delved into not only advanced aerodynamics, but instrumentation and sensing systems that enabled flight in blind flight conditions that truly are blind.

Expanding into the entire flight range for fixed-wing aircraft, Aurora managed totally-pilot-free trips for its Centaur test vehicle.  The video expands on other Aurora projects.

Dr. Langford’s career has been distinguished by many awards, including a DARPA honor for the company’s Lightning Strike advanced Vertical TakeOff and Landing (VTOL) craft in 2016.  A bit like a Lilium on steroids, Lightning Strike will combine jump starts with high speed.

Designs are certainly not limited to VTOL, though, extending into large airliners with advanced aerodynamics, such as Aurora’s D8 “Double Bubble, seen here at the end of longer blog entry on future airliners.

Aurora’s D8 “Double Bubble” concept could lower drag, increase payload and save fuel

Dr. Langford’s long and fruitful career, highlighting his ability to find novel and creative solutions to virtually every type of aeronautical problem, was well presented by Mr. Clancy, himself an innovator of note.  This is indeed a great addition to PADA’s decades of recognizing designers of accomplishment and merit.


In battery making, recipes for electrolytes play an important part of the whole.  In a new formula whipped up by Zhengzhou University, Tsinghua University and Stanford University, Lithium (Li), Lanthanum (La), Zirconium (Zr), Tantalum (Ta), and Oxygen (O) form a ceramic tube as the battery’s electrolyte.  This tube is centered in new solid state Lithium Sulfur and Lithium Selenium batteries.

Researchers filled that tube with a liquid lithium electrode, and immersed the tube in a bath of carbon black and liquid selenium or sulfur in a stainless steel container.

Cylinder within cylinder layout may obviate use of more conventional manufacturing methods

The team’s paper, “High Energy-Density Solid Electrolyte-Based Liquid Li-S and Li-Se Batteries,” published in the October 15 edition of Joule, explains the new batteries should be capable of delivering energy densities of around 2,600 Watt-hours per kilogram for the lithium-sulfur chemistry and 1,160 Wh/kg. for lithium-selenium.   Currently, researchers have achieve 500 Wh/kg, double the best Li packs today.  This can be achieved at cost of $41 per kilowatt-hour for the Li-Se battery and $15 per kW-hr for the sulfur-based version.

The abstract for the paper reads: “Lithium-sulfur (Li-S) and Lithium-selenium (Li-Se) batteries are considered as promising candidates for next-generation battery technologies, as they have high energy density and low cost. However, due to the use of a solid Li-metal anode and a liquid organic electrolyte, the current Li-S and Li-Se batteries face several issues in terms of Coulombic efficiency and cycling stability, which seriously impeded their development. Here, we report solid-electrolyte-based liquid Li-S and Li-Se (SELL-S and SELL-Se in short) batteries. The batteries use a Li 6.4La 3Zr 1.4Ta 0.6O 12 (LLZTO) ceramic tube as electrolyte and work at temperatures higher than the melting point of Li; thus, polysulfide or polyselenide shuttle effects and Li dendrite growth are effectively prevented, and high energy density, together with high stability, fast charge/discharge capability, high Coulombic efficiency, and high energy efficiency, can be achieved. The SELL-S and SELL-Se batteries provide broader platforms for constructing high-energy, high-power, long-lifetime, and low-cost energy storage.”

Differential transfer of materials during lithiation may contribute to high energy density

The combination of low cost and high output could be a real winner in the commercial market, and would open the way for large-scale energy storage for wind and solar power.  Now only at the laboratory stage, the promising technology makes one hope this can be quickly scaled up and adopted by significant users.

Batteries in which lithium is a major factor may become costly to produce in the United States, which is ninth in the world’s use of the metal for batteries.  Spreading that cost among other, cheaper materials might help.

According to Fortune magazine, a ton of lithium (battery grade) would bring $20,000 in 2016Sulfur tends to fluctuate in price, ranging from $30 per ton to $480 for medical grade material. Selenium would not be a cost saver, averaging around $48,000 per ton in 2016.  Carbon black is a bargain at $93 per ton despite recent price increases.  Lanthanum, a rare-earth mineral, can be had for $1,000 to $1,200 per ton, although laboratory grades sell for much more.  High quality Zirconium oxide can sell for anywhere from $1.5 to $70 per kilogram.  Most costly, tantalum, reputed to be a conflict metal sold for !51,800 per ton in 2018.

It must take minute amounts of certain of these materials to enable low costs for SELL-S and SELL-Se batteries.  We hope researchers can find ways manufacture such cells on an equally economic basis.


The Villiger Traveler Updated

Urs Villiger flew his Traveler TR230 four-seat touring craft about 10 years ago.  He started revising the Cessna-like vehicle two years ago, turning it into a more aerodynamic and economical machine.  His changes turned the Traveler into a hybrid aircraft and relocated the propeller to the vertical stabilizer.

Travler on static display at Smart Flyer Challenge in Grenchen., Switzerland

Reflecting professor Dipl.-Ing. Rudolf Voit-Nitschmann’s configurations he developed for Icare II and  e-Genius, the low-drag placement of the drive motor near the top of the vertical fin confines the added drag caused by the propeller’s acceleration of air over the aircraft’s skin to the top-most part of the fin and rudder.  Compare the area exposed to propeller blast to that of a conventional nose-mounted engine “tractor” type aircraft.

Icare II (foreground) and e-Genius were both products of Rudolf Voit-Nitschman’s mentoring and students at Stuttgart University.  e-Genius was second-place winner in 2011 Green Flight Challenge

On static display at this September’s Smart Flyer Challenge in Grenchen, Switzerland, the newly revised Traveler showed a streamlined nose fairing that holds a gas turbine (reported from a Panavia Tornado fighter’s auxiliary power unit (APU) attached to the UQM motor/generator.

Traveler has turbine reportedly from Panavia Tornado jet fighter coupled with UGM motor/generator

That unit charges the craft’s batteries with up to 100 kilowatts of continuous power output.

Batteries in turn energize the tail-mounted motor that swings a five-blade MT propeller.  The motor is being developed to produce 200 kilowatts (268 horsepower) and weigh only 30 kilograms (66 pounds).

Traveler promises to be quiet and efficient with the Mühlbauer five-blade propeller . The concept was first used in the German e-Genius.  Photo: Peter Brotschi

All this and more is taking place at Evolaris, a Swiss company that does aircraft structures, batteries, power electronics and batteries and even software – just about everything needed for creating electric airplanes.

Two water-cooled power inverters, housed in carbon fiber and aluminum, control the motor.  The redundant units enhance reliability.

Evolaris-devised intelligent software regulates the whole system, communicating between individual components and displaying relevant information for the pilot.  In the meantime, Evolaris engineers are making sure everything works a

Drop Test Fahrwerk

Drop-Test Fahrwerk: abgehakt! Trotz heftigem Herzklopfen beim Auslösen: die Rumpfstruktur und das Fahrwerk haben den Drop-Test ohne Schaden überstanden – nächste Baustelle: Belastungstest Rumpf!

Posted by Traveller Hybrid on Wednesday, March 28, 2018

The drop test proves the limits of Traveler’s landing gear and its ability to withstand a hard landing. 

Der ganze Klappenantrieb ist komplet im Flügel integriert. Das Ein- und Ausfahren erfolgt über 2 Spindeln, welche durch eine Kette angetrieben werden.

Posted by Traveller Hybrid on Wednesday, December 19, 2018

Flap operation is smooth, providing additional wing area for slow landings or enhanced takeoffs.

Specifications show the 12 meter wingspan machine will weight 1,450 kilograms (3,190 pounds) fully loaded, including 400 kilograms (880 pounds) of batteries.  The motor will produce 160 kilowatts (214 hp.) with a peak output of 220 kW (295 hp.).  Traveler will cruise at 220 kilometers per hour (136.4 mph) for up to an hour and 30 minutes.

The latter figure is with batteries only.  The range extender should extend that, living up to its name.