Solar Cargo Gliders : The possibility

in this video we will explore power gliders and in particular electric power gliders we will investigate how they can be used for transportation of goods at extremely low cost to the remote corners of many countries it is interesting to note that in the early days of Aviation gliders held a prominent role in transportation an example of this were military gliders during World War II gliders transported troops and heavy equipment to combat zones they were designed by the US Germany Britain and even the Soviet Union for takeoff they were toored in the air by a larger powered aircraft high altitude sail planes were even built for reconnaissance such as the DFS 228 but were never flown a more audacious concept was the anof A40 it was the soviet's attempt to allow a tank to Glide onto a battlefield after being toored a loft by an airplane it was found to be unworkable but imagine the formidable sight of a tank landing on a warfront so why can we not look at gliders again they make the perfect aircraft for midm Logistics after all there is now technology to power them with lightweight Motors and batteries and even with fuel cells the airframe can be made lighter and stronger using Composite Materials as compared to what that was used during the World War II era they don't need to be towed anymore and can be easily made as self-launching using autonomous flying controls they can be flown without a pilot and carry even more payload what gives the power gliders the advantage is their high lift to drag ratio this means that for every kilowatt hour of energy spend the glider is the aircraft that can go the furthest and it's best illustrated by the range equation for the electric aircraft the range is equal to the specific energy of the battery pack which is between 150 to 250 water per kilogram times the propulsive efficiency times the inverse of acceleration due to gravity times the lift to drag ratio times the battery Mass fraction of the aircraft now you can see from the equation that the lift to drag ratio has a lot of bearing on the range of an aircraft for Extreme Performance gliders the lift to Dag ratios of over 50 have been recorded but even for most gliders finding lift to drag ratio of over 30 is common for large cargo gliders using modern design techniques the lift to drag ratio of 20 is doable even the vaco C pg4 military glider with very boxy Fus Lodge and low aspect ratio Wings had the lifter drag ratio of 15 it is true that gliders are fair weather aircraft but there are many regions across the globe that are dominated by high pressure for most part of the year for example the regions above and below the intertropical Convergence Zone in the recent past we have witnessed power gliders completing Coast to Coast Journeys across the US Australia and Europe they move slowly through the air the never exceed speed for most is about 100 mph or less although some Gliders can go up to 180 mph for Middle mile Logistics that is transporting goods from Warehouse to Warehouse or port to Warehouse powered Gliders can play an important role these gliders would be large in size such as the ones used by the military solar panels on the Gliders can enhance the range note that the state-of-the-art high efficiency thin film solar cells can provide over 852 wats of power for just 1 kilogram of added weight solar power gliders in the past have achieved high endurance with much heavier monocrystalline silicon solar cells that provided just 370 2 wats per kilogram these lower power density solar cells have been used by aircraft like the solar impulse Sunseeker one the Sunseeker Duo and the solar Stratos if the state ofthe Earth solar cells which are the multi Junction solar cells are used then it can generate 6.4 kilowatt instead of 5 kilowatt and this would further increase the range these solar cells are used mostly in satellites even at present the Sunseeker Duo has an endurance of more than 12 hours it has a l byd ratio of 38 a modified version of the duo with more room and with autonomous flying capability can easily transport goats of up to 200 kg to distances of up to 300 mies larger Gliders can also be built that can be assisted in take off with aircraft catapults on the launch site these aircraft may not be suitable to fly over large builtup areas but think of the subsaharan Africa where there are no proper roads between population centers there are mostly dirt tracks which get muddy during the rainy season likewise there are areas where the distance might be small but the terrain is difficult the cargo Gliders can therefore be used in these situations dropping loads via parachute at present zipline a delivery company uses fix wi drones to provide payload deliveries of up to 1.8 Kg on Peak charge their drones can fly distances of up to 300 km but the maximum distance they can deliver has been limited to 80 km to complete the round trip and have some Reserve capacity the zipline drones use a launch catapult for takeoff and a sophisticated Catch Fire system to land over a soft Landing Pad this means that the energy required for take off and Landing the drones doesn't come from the onboard battery similarly cargo Gliders can be assisted in takeoff and Landing there are different ways of attaching propellers to the gliders which give them the ability to self-launch and sustain flight the Sansa Duo had a propeller at the empal but most self- powerered gliders use retractable pile on mounted propeller that is nestled in the fuse Lodge just behind the cockpit it folds out when required and folds back in when not in use there are some powered gliders that use front electric sustainers or FES for short the front configuration is aerodynamically more clean compared to typical retractable pilin configuration as there is no additional drag of a pylon so lower power is required for equal performance the propellers in the FES neatly fold back into the grooves in the fuse latge when not in use the disadvantage of the FES is that the propeller diameter is limited to the landing gear height larger propellers can be attached at the rear like in the Sunseeker one another configuration that can be explored for cargo gliders is the tandem Wing configuration this was first used by the solar glider called AO which took its first flight in 2016 this aircraft uses an interesting Hybrid Power System where part of the power comes from solar cells part comes from hydrogen fuel cells and some comes from biojet fuel that is drive from algae this aircraft has already done an 8h hour flight and has reached an altitude of 7,040 Ft the aircraft was designed by Raphael nelli who has Ambitions to cross the Atlantic with this plane the tandem Wing configuration allows more area for the solar cells since its Inception the AOL has had design modifications strs were added between the lower front wing and the upper rear wing to stiffen the two light independent structures the AOL 2 design that was revealed in a video shows an extended endplate from the lower wing attached to the upper Wing this makes it a box Wing configuration a box wing also allows for high aspect ratio of the Wings and ensures greater structural Integrity furthermore the AOL 2 has also got distributed propulsion it has four propellers instead of a single large propeller that was used by its predecessor another example of how effective the solar tandem Wing configuration is come comes in the form of the solar X1 drone this drone has a 12-hour endurance and a range of 600 km so clearly there is an opportunity to develop solar cargo gliders there are many design templates that can be followed including a box Wing configuration these gliders would be sustainable noiseless and would be able to deliver cargo at extremely low cost to distances of 100 to 300 mil and with this the video is concluded if you learn something from it then please do give it a thumbs up thank you for your attention

Channel: Electric Aviation

Views: 36,305

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Id: H-zvzOC8dzA

Length: 10min 8sec (608 seconds)

Published: Fri Nov 24 2023