How Can We Design a Solar Drone with Long Duration Flight and High Payload?

  • Context: Graduate 
  • Thread starter Thread starter yuiop
  • Start date Start date
  • Tags Tags
    Design Drone Solar
Click For Summary

Discussion Overview

The discussion centers on the design of solar-powered drones capable of long-duration flight and carrying significant payloads. It explores various approaches to enhance flight duration, including energy storage methods and aerodynamic considerations, as well as the feasibility of such designs for applications like internet coverage in remote areas.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that gaining altitude and gliding overnight could reduce the need for heavy batteries, focusing on the importance of sink rate for maintaining altitude during the night.
  • Concerns are raised about wind conditions at high altitudes (around 50,000 ft) and whether higher wing loading and glide speed are necessary to maintain station.
  • One participant shares experiences from a solar-powered model plane competition, noting challenges in maintaining height and the importance of optimizing performance with variable pitch props.
  • Questions are posed regarding the standard use of pusher props in solar-powered models, with some suggesting it may help with center of mass placement in designs lacking a fuselage and tail.
  • A hybrid approach combining altitude gliding and battery use is mentioned as a potential solution for achieving extreme duration flights with realistic payloads.

Areas of Agreement / Disagreement

Participants express a range of ideas and concerns, indicating that multiple competing views remain regarding the best design strategies for long-duration solar drones. The discussion does not reach a consensus on the most effective approach.

Contextual Notes

Limitations include the dependence on specific design parameters and assumptions about environmental conditions, as well as unresolved questions about the feasibility of achieving flight durations of years.

yuiop
Messages
3,962
Reaction score
20
Recently, Facebook suggested solar powered drones could be used to provide internet coverage in remote areas and they would basically act as low altitude 'geostationary' satellites. The current duration record for a solar drone is 2 weeks using energy stored in batteries during the day, to keep the aircraft airborne overnight. http://www.barnardmicrosystems.com/UAV/milestones/solar_powered.html

What is the best way forward to design a drone that can stay up for months or even years? For example another way to store energy during the day is to gain altitude and glide overnight, eliminating the requirement for heavy and expensive batteries. I think the key parameter here is the sink rate rather than the glide ratio as the glider would have to keep itself in the air for roughly 12 hours each night without losing too much altitude.

Is wind a problem at the altitudes considered (around 50,000 ft) requiring higher wing loading and glide speed to penetrate into the winds and hold station? What other considerations are there for a long duration solar aircraft with a significant payload and requiring power to transmit internet data? Are flight durations of years feasible?
 
Last edited:
Physics news on Phys.org
Several years ago (>15) I attended the Militky Cup event in Switzerland. One event was an informal competition for solar powered model planes of around 3m span. They were typically very marginal on performance and occasionally had difficultly maintaining height if the sun went in. No doubt things have improved since then but I bet it's still a challenge to build a small plane that can fly on the low power available.

I recall the best planes were flying wings covered in cells. They had fancy electronics including variable pitch props so that they could adjust the load presented to the cells and keep them operating close to their sweet spot. If you used your hand to cast a shadow on the cells you could see the prop pitch change!

There might be some vids on youtube but there were a lot of other competition classes as well that weren't solar powered.
 
Photo from 1997...

solnf1.jpg
 
CWatters said:
Photo from 1997...

Are pusher props pretty standard design for solar powered models? If so, what is the thinking behind that?
 
yuiop said:
Are pusher props pretty standard design for solar powered models? If so, what is the thinking behind that?
It probably helps keep the center of mass in the right place, if there is no fuselage and tail.
 
So altitude and overnight gliding or batteries for extreme duration solar drones with a realistic payload? (Or hybrid?)
 

Similar threads

What can we learn from a friend's solar home data in Vermont?
  • · Replies 1 ·
Replies
1
Views
3K
Rocket design -300km range, 5-15kg payload, 200mg accuracy
  • · Replies 8 ·
Replies
8
Views
6K
Why is the U-2 nicknamed the Dragon Lady?
  • · Replies 4 ·
Replies
4
Views
9K
Why can’t decay heat be harnessed to safely shutdown a nuclear reactor?
  • · Replies 14 ·
Replies
14
Views
11K