19
votes
Can quadrotors be used for commercial passenger flights?
The three most important factors in passenger air travel are safety, safety & safety. So that is where most of the questions will focus on, and where most of the engineering effort will be put ...
- 61.2k
19
votes
Accepted
Do quadcopter propellers break the sound barrier?
Almost certainly not. Given the comments specifying a $0.5$ inch radius (blade length,) that means the circumference of the path of the blade tips would then be
$$2 \pi \cdot 0.5 \, \text{inches} \...
- 19.4k
18
votes
Can a passenger drone perform auto-rotation?
That drone has fixed-pitch rotors, and that pitch is optimized for thrust, not for autorotation. In the absence of power, those rotors won't autorotate. They will stop rotating 'in the right way' and ...
- 10.8k
16
votes
Is possible to stick two '2-blade' propellers to get multi-blade propeller?
Sure, this is not only possible, but even has some advantages over single-plane propellers. The catch is you ideally want the two to spin in opposite directions to cancel out torque and vibration.
You'...
- 14.1k
12
votes
What‘s the thrust of two stacked propellers?
There's a really interesting paper by Manikandan Ramasamy (Hover Performance Measurements Toward Understanding
Aerodynamic Interference in Coaxial, Tandem, and Tilt Rotors, Journal of the American ...
- 3,671
12
votes
Is possible to stick two '2-blade' propellers to get multi-blade propeller?
It's done sometimes, for ultralight aircraft and paramotors. Like this:
- 10.8k
11
votes
Can a passenger drone perform auto-rotation?
Simple answer. No.
A drone with fixed wing propellers such as the one you describe can not autorotate. For autorotation to work the pitch of the blades needs to be variable.
At the instant of engine ...
- 211
9
votes
Can I fly this six motor drone?
No, you may not fly this drone. It weighs much more than 55 lbs. At least in the United States, you have to have an FAA clearance and hold an FAA Part 107 Certificate to operate anything that heavy.
- 694
8
votes
Can quadrotors be used for commercial passenger flights?
What are the advantages that quadrocopters have over conventional helicopters?
Super cheap flight control achieved via electronic control of individual electric motors. (Basically, it means avoiding ...
- 1,362
8
votes
What is the weight of ballistic recovery systems?
The smallest BRS listed here is certified up to 600 pounds (272 kg) of aircraft weight. That should be more than enough for a small jetpack or personal quadcopter. This system weighs about 22 pounds (...
- 71.8k
7
votes
Could a tilt quadcopter use turbofan engines?
In a way, this has been done already half a century ago.
When NATO decided to try a VTOL strategy, the Harrier was not the only result. There was even a supersonic VTOL fighter, and it used ...
- 228k
7
votes
Do quadcopter propellers break the sound barrier?
It's possible, but I would say unlikely. Supersonic propeller tips really mess with efficiency.
The tip speed of many aircraft propellers is close to supersonic, and if not properly controlled can ...
- 68.2k
7
votes
Can a passenger drone perform auto-rotation?
I am a career helicopter pilot who enjoys watching the development of drone technology. I can tell you for certain that this aircraft is incapable of autorotation. A parachute would be it's best ...
- 81
7
votes
Accepted
Must quadcopters have the same propeller sizes?
The main point of a quadcopter is that it can be controlled by engine power using much simpler fixed-pitch rotors¹. Assuming this construction, you need to be able to separately adjust power of
...
- 56.2k
7
votes
What are the failure mode(s) for flying cars in case of power loss?
As I am closely working on some of these projects, I think I can answer.
Let me start from:
if the power fails
this is a rather extreme situation, since everyone is including emergency ...
- 32.3k
5
votes
Can quadrotors be used for commercial passenger flights?
An important point is that that type of aircraft can't glide in autorotation, as helicopters are able to do in case of engine trouble. It will drop like an stone...
- 10.8k
5
votes
Accepted
If the Quadcopter is a MIMO Nonlinear System, How Can it be Controlled using PID?
If the Quadcopter is a MIMO Nonlinear System, How Can it be Controlled using PID?
Exactly as you mention later:
Does the model need to be linearized so that PID algorithms can be used?
Yes, that'...
- 32.3k
5
votes
Accepted
How is the flight of a tricopter controlled?
There are few examples of three-rotor helicopters. On of them is the Cierva W.1 Air Horse. According to Wikipedia, torque balance, and hence, yaw control
'was provided by slightly inclining each rotor ...
- 10.8k
5
votes
Accepted
Just got a quadcopter, and not sure about a piece that came with it
This question does not belong in this SE, however this cable is for uploading pictures from the SD Card (Supposedly from your drone camera) to your computer via USB. You just plug the SD Card in the ...
- 11.9k
5
votes
Accepted
Looking for the correct propeller shape to create a small copter
Use Mark Dela's XROTOR - it will give you the chord and twist distribution over span for a given speed, torque and thrust (well, two out of three).
It is based on Larabee's theory (PFD!) for a ...
- 228k
5
votes
Why is a model quadcopter 'better' than a helicopter? Why doesn't this scale up to the full-size versions?
Cheap MEMS gyroscopes have been on the market only since maybe 10 years. Before you needed more bulky and expensive gyros. Also, cheap and powerful micro controllers which can process the sensor data ...
- 228k
5
votes
Can quadcopter-like UAVs ever get significantly quieter? Any candidate technology?
A quiet fan is a large fan.
(This should be understood in relation to either mechanical power or lift. Of course, a multi kilowatt industrial turbine is way noisier than the fan cooling your computer.)...
- 1,172
5
votes
Accepted
What happens if one or more rotors are stopped during autorotation on a quadrotor?
After watching the video the problem he was having was in keeping it horizontal. It appears that the software isn't able to control the unpowered motors.
I know absolutely nothing about quads but I'm ...
- 28.3k
5
votes
Could a tilt quadcopter use turbofan engines?
The main reason V-22 uses propellers is efficiency. To get high thrust for power, you need to affect a lot of air and that requires a large propeller. The V-22 has huge propellers, closer to ...
- 56.2k
5
votes
Does the direction of rotation of the propeller affect the direction of the thrust generated?
It depends.
For that simple kind of a fan with flat blades, yes. For anything that was ever installed on a full scale airplane, it will generate no or very, very little thrust, more likely backward.
...
- 56.2k
5
votes
Accepted
Could a quadcopter fly if its propellers were encased in cylindrical tubes?
Yes. It would be able to turn. Of your 4 propellers, 2 spin clockwise and 2 spin counterclockwise. The torques cancel out. To make it spin, you run the 2 clockwise propellers a little faster and the ...
- 5,463
5
votes
What disadvantages does flying a drone close under a ceiling have?
For a quadcopter, flying close underneath a flat surface will increase the amount of lift produced, but this will make it harder to control (unless the quadcopter is equipped with appropriate control ...
- 5,751
5
votes
Is possible to stick two '2-blade' propellers to get multi-blade propeller?
Any propeller 'unit' has been designed for a certain set of conditions: rotational-speed/air-speed/power/etc.
If you then double-up in any way, then you can be assured that for the same conditions, ...
- 418
4
votes
Accepted
How can this single-prop drone maintain stable (rotating) attitude and position?
You can read all about it in their paper (which actually reads quite nicely)
http://flyingmachinearena.org/wp-content/publications/2016/zhaIEEE16.pdf
First, the parameter space (so, location of ...
- 12.7k
Only top scored, non community-wiki answers of a minimum length are eligible