Solar Impulse answers to questions of users of Geektimes
In the post “Wings, Sun, Batteries” I asked you to ask questions to the Solar Impulse team. Answers are ready and translated into Russian. Welcome under habrakat.
Note: if you are well versed in aviation and saw inaccuracies in the translation, please write in private messages. Thank!
1. This car will be in the air only due to solar panels, or glider “chips” will be used: ascending currents and the like ...
')
Yes, the machine will use other chips. For example, at night the plane plans from 8500 meters to 1500 meters, after which the engines are turned on again and work on the energy collected during the day.
2. What will be the schedule for the flight of this vessel?
While the exact route of the world tour is not disclosed, but you can get more information here .
2.1 Pilots schedule:
Solar Impulse co-founders and partner pilots Bertrand Picard and Andre Borschberg will face (in turn) huge physical exertion during their world tour . Five days and nights they will have to huddle in 3.8 cubic meters. At the same time, in addition to them in the cabin will be oxygen cylinders, food and rescue equipment. Pilots will have to give interviews, check mail, observe beautiful landscapes and even sometimes directly fly a plane when the Stabilization Augmentation System (SAS, below) is turned off.
What is on the topic of sleep: each of the pilots will sleep two or three hours a day in several visits for 20 minutes. How will they deal with sleep deprivation? Both Andre and Bertrand possess techniques for rapidly achieving deep sleep at high levels of concentration. Read more - in this video:
3. What are the security measures for flying over the oceans (it is obvious that each kg is worth its weight in gold in such an apparatus)?
Pilots are well equipped to cross the oceans: they have a life raft, GPS transmitters, flares and power for emergency situations. Currently Bertrand Piccard (https://twitter.com/bertrandpiccard) and Andre Borschberg (https://twitter.com/Andreborschberg) are in Nordholz, Germany, and are training there to cope with emergency situations during the flight of the ocean.
4. On the infographic indicated the weight of the vessel, and how much payload can you take?
Unfortunately, the payload is minimal. The pilot does not take any baggage, and he must weigh no more than 110 kg together with his flight suit. For a long flight (5 days and 5 nights), you can take a maximum of 30 kg of food and water.
5. What is the average power consumption when flying at a certain height? Understandably, it depends on a variety of parameters, but it is still curious to know at least approximately (and at the same time evaluate how long the batteries last).
The maximum battery capacity is 38 kWh. At full charge, you can fly during the night, while there is no sun and the engines operate at minimum power. And with a full charge and with the sun the plane will be able to fly endlessly. As CEO Solar Impulse, Andre Borschberg, says, “We have an aircraft that is as stable as possible in terms of energy, it remains only to make an equally powerful pilot.” Solar Impulse 1 made the first and only day and night flight in 2010, here's a video:
6. Does this device fly by itself? Do I need to charge the batteries in advance or the power of the panels and enough for takeoff?
Batteries must be fully charged before take-off and flight through low clouds. Also, the aircraft needs the help of a ground crew to get to the runway from the hangar. More information about the work of the team - in this video:
7. Are they going to use lithium sulfurum batteries and what prospects do they see in this direction?
No, for now we consider the optimal use of lithium-polymer batteries with an efficiency of 260 Wh / kg.
8. How are they struggling with temperature differences on photovoltaic cells and is there any icing on the components of this device?
As a rule, solar panels are more effective at low temperatures.
9. As far as I understand, photocells have their normal shape already in a bend (not a flat plate compressed forcibly, namely an arc by itself), if so, what is the peak bend of a photo cell on their wing? And what voltage (maximum bending) can their even photocell plate withstand?
The angle at which the panels are embedded in the wings is 2.2 degrees.
10. During the flight, do they burst (at least some part of it?) From any mechanical damage? What do they do to protect panels from mechanical stress?
During the flight, the panels do not burst. They are protected by UV-resistant, moisture-resistant rubber, 17 microns thick.
11. How effective is vibration damping their wing? Do they exist at all? Wing collected on composite materials? What kind?
The upper surface of the wings is made of solar panels, the bottom is made of ultra-light fabric. The wing spar is completely made of sandwich panels using carbon fiber. There is a video in German, more about this.
12. Can you learn more about engines and propellers? What is the diameter, pitch and why these parameters were chosen? Are most effective both near the ground and in conditions of small resistance to a screw at a height? Or does it have little effect, because the height is not so big - up to 10 km?
Solar Impulse 2 engines develop power from 15 to 70 horsepower (4 engines of 17.4 horsepower). Engines are located under the wings. The maximum speed of rotation is 525 revolutions per minute. The diameter of the propeller is 4 meters, only 2 blades for each propeller. System efficiency - 94%.
13. Well, what is the engine itself?
Engine own production. Four brushless electric motors, two on each wing, are located 4.95 meters away from each other.
14. How durable and wind sensitive is the glider?
Very sensitive! For take-off, a wind of no more than 5 knots is needed, the maximum force of the opposing wind is 3 knots. For landing, the wind must not be stronger than 7 knots. The maximum rate of climb for turbulence is 2 m / s.
15. What is the cost (at least approximate) of the individual components? Accumulators, photocells, engines, glider (composites for it).
Both Solar Impulse aircraft were designed from the latest materials and components, so most of them were not purchased at all. But some technologies of our partners become available. The total cost of the project is about 115 million euros.
16. How can they comment on the Qinetiq Zephyr project? This is a UAV, but they are certainly familiar with this project. What prospects do they see for it and what else is the industry lacking for stratospheric UAVs for full-fledged exploitation in everyday life, so to speak?
Solar-powered drones can become tele-communication platforms cheaper than satellites. I think we will soon see the commercial applications of this idea.
Although we do not expect that solar-powered aircraft will come into commercial operation in the near future, we must remember the past. In 1903, when the Wright brothers first flew 200 meters by plane, could they imagine that after 24 years Lindberg would fly over the Atlantic Ocean? He was alone on board, and 30 years later, the plane already contained 200 passengers and could make the same flight in just 8 hours. Yes, and at about the same time two people walked across the moon.
The first solar-powered airplanes appeared in the 1980s, but they could fly only during the day and were not able to save energy. As soon as the sun disappeared behind the clouds - they needed to land. So they showed the limitations of solar energy, and not its capabilities. Other projects flew on fuel cells, electricity was generated in the forest using hydrogen.
And Solar Impulse is the first aircraft capable of storing energy and wasting it at night. This makes the project unique.
17. Is it possible to get acquainted with more or less detailed drawings of their airframe somewhere?
Unfortunately, they sent only these two infographics.
18. What difficulties did you encounter during the project?
The original goal was to build a plane capable of crossing the Pacific Ocean and the Atlantic. The design and simulation of this process has shown that it takes 5 days and five nights to overcome each ocean. In order to save energy as much as possible, we had to minimize the weight of the components, and at the same time provide the pilot with everything necessary. To reduce the weight, we even had to make a cabin that is not under pressure - the pilots need to wear a mask all the time, and take oxygen on board.
But on the subject of technical complexity: in July 2012, the side member of the Solar Impulse wing broke. Read more This is a dramatic event described in a blog .
19. What is with the thrust-weight ratio?
Unfortunately, these data are not disclosed.
20. What are the pilot selection criteria?
Solar Impulse test pilot Markus Sherdel is a German pilot who takes on the main risk of testing an experimental aircraft. He has tremendous aviation knowledge and excellent management capabilities.
For various missions, the founders of the project, both with vast experience in aviation, become pilots. Bertrand Piccard in the field of hang-gliding and aeronautics . Andre Borschberg - fighter pilot . Both have knowledge of survival techniques, including self-hypnosis and yoga.
21. What smart electronics is installed?
Everything was created from scratch, including the Mission Control Center, which monitors the telemetry communications system. So this is quite a “smart” and yet absolute system. Altran also created the Stability Augmentation System (SAS) specifically for the Solar Impulse 2 for a round-the-world mission.
22. Is there an autopilot? If so, can he use thermals?
Yes! His name is Stability Augmentation System (SAS), and it was created by Altran so that the pilot could take a break. It allows Solar Impulse 2 to fly for several hours without human control. Read more about SAS .
23. What is the pilot ration?
Nestlé Health Science has signed a partnership agreement with Solar Impulse and will develop scientifically based personalized menus for pilots for a world tour in 2015. Each pilot will receive an individual menu. The goal is to create a rich and healthy, and at the same time delicious food that will stay fresh and that will just be cooked in a small space of the plane. Nestle will include some of the already existing products, and packaging experts will plan how to keep food fresh under temperature and barometric conditions and changes, as well as how to simplify cooking.
24. The lifetime of Solar Impulse 2, how long can it survive under adequate conditions?
The limitations of the aircraft primarily concern the pilot. The plane itself will be able to fly indefinitely under the right conditions, but the pilot needs to eat, rest and exercise. But something can always go wrong, as was seen during a trip to America . We have foreseen a lot, including, for example, the possibility of a battery transfer from its engine nacelle to another when the engine fails.
Note: if you are well versed in aviation and saw inaccuracies in the translation, please write in private messages. Thank!
1. This car will be in the air only due to solar panels, or glider “chips” will be used: ascending currents and the like ...
')
Yes, the machine will use other chips. For example, at night the plane plans from 8500 meters to 1500 meters, after which the engines are turned on again and work on the energy collected during the day.
2. What will be the schedule for the flight of this vessel?
While the exact route of the world tour is not disclosed, but you can get more information here .
2.1 Pilots schedule:
Solar Impulse co-founders and partner pilots Bertrand Picard and Andre Borschberg will face (in turn) huge physical exertion during their world tour . Five days and nights they will have to huddle in 3.8 cubic meters. At the same time, in addition to them in the cabin will be oxygen cylinders, food and rescue equipment. Pilots will have to give interviews, check mail, observe beautiful landscapes and even sometimes directly fly a plane when the Stabilization Augmentation System (SAS, below) is turned off.
What is on the topic of sleep: each of the pilots will sleep two or three hours a day in several visits for 20 minutes. How will they deal with sleep deprivation? Both Andre and Bertrand possess techniques for rapidly achieving deep sleep at high levels of concentration. Read more - in this video:
3. What are the security measures for flying over the oceans (it is obvious that each kg is worth its weight in gold in such an apparatus)?
Pilots are well equipped to cross the oceans: they have a life raft, GPS transmitters, flares and power for emergency situations. Currently Bertrand Piccard (https://twitter.com/bertrandpiccard) and Andre Borschberg (https://twitter.com/Andreborschberg) are in Nordholz, Germany, and are training there to cope with emergency situations during the flight of the ocean.
4. On the infographic indicated the weight of the vessel, and how much payload can you take?
Unfortunately, the payload is minimal. The pilot does not take any baggage, and he must weigh no more than 110 kg together with his flight suit. For a long flight (5 days and 5 nights), you can take a maximum of 30 kg of food and water.
5. What is the average power consumption when flying at a certain height? Understandably, it depends on a variety of parameters, but it is still curious to know at least approximately (and at the same time evaluate how long the batteries last).
The maximum battery capacity is 38 kWh. At full charge, you can fly during the night, while there is no sun and the engines operate at minimum power. And with a full charge and with the sun the plane will be able to fly endlessly. As CEO Solar Impulse, Andre Borschberg, says, “We have an aircraft that is as stable as possible in terms of energy, it remains only to make an equally powerful pilot.” Solar Impulse 1 made the first and only day and night flight in 2010, here's a video:
6. Does this device fly by itself? Do I need to charge the batteries in advance or the power of the panels and enough for takeoff?
Batteries must be fully charged before take-off and flight through low clouds. Also, the aircraft needs the help of a ground crew to get to the runway from the hangar. More information about the work of the team - in this video:
7. Are they going to use lithium sulfurum batteries and what prospects do they see in this direction?
No, for now we consider the optimal use of lithium-polymer batteries with an efficiency of 260 Wh / kg.
8. How are they struggling with temperature differences on photovoltaic cells and is there any icing on the components of this device?
As a rule, solar panels are more effective at low temperatures.
9. As far as I understand, photocells have their normal shape already in a bend (not a flat plate compressed forcibly, namely an arc by itself), if so, what is the peak bend of a photo cell on their wing? And what voltage (maximum bending) can their even photocell plate withstand?
The angle at which the panels are embedded in the wings is 2.2 degrees.
10. During the flight, do they burst (at least some part of it?) From any mechanical damage? What do they do to protect panels from mechanical stress?
During the flight, the panels do not burst. They are protected by UV-resistant, moisture-resistant rubber, 17 microns thick.
11. How effective is vibration damping their wing? Do they exist at all? Wing collected on composite materials? What kind?
The upper surface of the wings is made of solar panels, the bottom is made of ultra-light fabric. The wing spar is completely made of sandwich panels using carbon fiber. There is a video in German, more about this.
12. Can you learn more about engines and propellers? What is the diameter, pitch and why these parameters were chosen? Are most effective both near the ground and in conditions of small resistance to a screw at a height? Or does it have little effect, because the height is not so big - up to 10 km?
Solar Impulse 2 engines develop power from 15 to 70 horsepower (4 engines of 17.4 horsepower). Engines are located under the wings. The maximum speed of rotation is 525 revolutions per minute. The diameter of the propeller is 4 meters, only 2 blades for each propeller. System efficiency - 94%.
13. Well, what is the engine itself?
Engine own production. Four brushless electric motors, two on each wing, are located 4.95 meters away from each other.
14. How durable and wind sensitive is the glider?
Very sensitive! For take-off, a wind of no more than 5 knots is needed, the maximum force of the opposing wind is 3 knots. For landing, the wind must not be stronger than 7 knots. The maximum rate of climb for turbulence is 2 m / s.
15. What is the cost (at least approximate) of the individual components? Accumulators, photocells, engines, glider (composites for it).
Both Solar Impulse aircraft were designed from the latest materials and components, so most of them were not purchased at all. But some technologies of our partners become available. The total cost of the project is about 115 million euros.
16. How can they comment on the Qinetiq Zephyr project? This is a UAV, but they are certainly familiar with this project. What prospects do they see for it and what else is the industry lacking for stratospheric UAVs for full-fledged exploitation in everyday life, so to speak?
Solar-powered drones can become tele-communication platforms cheaper than satellites. I think we will soon see the commercial applications of this idea.
Although we do not expect that solar-powered aircraft will come into commercial operation in the near future, we must remember the past. In 1903, when the Wright brothers first flew 200 meters by plane, could they imagine that after 24 years Lindberg would fly over the Atlantic Ocean? He was alone on board, and 30 years later, the plane already contained 200 passengers and could make the same flight in just 8 hours. Yes, and at about the same time two people walked across the moon.
The first solar-powered airplanes appeared in the 1980s, but they could fly only during the day and were not able to save energy. As soon as the sun disappeared behind the clouds - they needed to land. So they showed the limitations of solar energy, and not its capabilities. Other projects flew on fuel cells, electricity was generated in the forest using hydrogen.
And Solar Impulse is the first aircraft capable of storing energy and wasting it at night. This makes the project unique.
17. Is it possible to get acquainted with more or less detailed drawings of their airframe somewhere?
Unfortunately, they sent only these two infographics.
18. What difficulties did you encounter during the project?
The original goal was to build a plane capable of crossing the Pacific Ocean and the Atlantic. The design and simulation of this process has shown that it takes 5 days and five nights to overcome each ocean. In order to save energy as much as possible, we had to minimize the weight of the components, and at the same time provide the pilot with everything necessary. To reduce the weight, we even had to make a cabin that is not under pressure - the pilots need to wear a mask all the time, and take oxygen on board.
But on the subject of technical complexity: in July 2012, the side member of the Solar Impulse wing broke. Read more This is a dramatic event described in a blog .
19. What is with the thrust-weight ratio?
Unfortunately, these data are not disclosed.
20. What are the pilot selection criteria?
Solar Impulse test pilot Markus Sherdel is a German pilot who takes on the main risk of testing an experimental aircraft. He has tremendous aviation knowledge and excellent management capabilities.
For various missions, the founders of the project, both with vast experience in aviation, become pilots. Bertrand Piccard in the field of hang-gliding and aeronautics . Andre Borschberg - fighter pilot . Both have knowledge of survival techniques, including self-hypnosis and yoga.
21. What smart electronics is installed?
Everything was created from scratch, including the Mission Control Center, which monitors the telemetry communications system. So this is quite a “smart” and yet absolute system. Altran also created the Stability Augmentation System (SAS) specifically for the Solar Impulse 2 for a round-the-world mission.
22. Is there an autopilot? If so, can he use thermals?
Yes! His name is Stability Augmentation System (SAS), and it was created by Altran so that the pilot could take a break. It allows Solar Impulse 2 to fly for several hours without human control. Read more about SAS .
23. What is the pilot ration?
Nestlé Health Science has signed a partnership agreement with Solar Impulse and will develop scientifically based personalized menus for pilots for a world tour in 2015. Each pilot will receive an individual menu. The goal is to create a rich and healthy, and at the same time delicious food that will stay fresh and that will just be cooked in a small space of the plane. Nestle will include some of the already existing products, and packaging experts will plan how to keep food fresh under temperature and barometric conditions and changes, as well as how to simplify cooking.
24. The lifetime of Solar Impulse 2, how long can it survive under adequate conditions?
The limitations of the aircraft primarily concern the pilot. The plane itself will be able to fly indefinitely under the right conditions, but the pilot needs to eat, rest and exercise. But something can always go wrong, as was seen during a trip to America . We have foreseen a lot, including, for example, the possibility of a battery transfer from its engine nacelle to another when the engine fails.
Source: https://habr.com/ru/post/362929/
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