Wind flow diagram of a quadcopter

I'm trying to determine the wind flow diagram around a quadcopter when it is in action. I looked up on internet but couldn't find any reliable source.

By wind flow diagram, what I mean is when my quadcopter is in mid-air, hovering at some fixed position, how the air is moving around it? All the directions are needed to be kept in mind, from top to bottom (vertical direction) and also the horizontal direction.

• Can you post a picture (hand-drawn, even) of what you are looking for? What exactly are you trying to do with this diagram? It sounds like you want something akin to a vector field or streaklines, but I'm not sure what this gets you because the aerodynamic shape of a quadcopter doesn't really matter. The quadcopter doesn't generate lift, it generates downward thrust.
– Chuck
Commented Feb 23, 2016 at 15:29
• Yes sir i want something like streak-lines. Absolutely, and for both planes. See the comment on the answer below to understand well. Your time is much appreciated. Commented Feb 25, 2016 at 4:49

The question needs some clarification, but at first thought here's a sketch of an answer.

The aerodynamics of rotors of a quad rotor can be simplified as independent from each other. Just to give a glimpse, here's a simple introduction to rotor aerodynamics, including near field flow directions, and average air velocity near (down) the rotor: Helicopter momentum Analysis.

Keep in mind that this is a very simple (yet practically quite an accurate) representation of the real flow phenomena near the vehicle.

Things that should be considered for a more detailed approach:

1. existence and interaction of multi rotors

2. rotor - body interaction

3. unsteadiness (the propellers are in fact creating a periodic flow)

4. environmental changes (wind, pressure change)

5. control induced variations (even in perfect air conditions, if the quad rotor is moving a camera or weight, there will be control commands, changing the flow a bit)

Etc.

• Yes.. First of all, Thank you very much for your answer sir. That is actually what i am looking for but a little more detailed one. Now the link above shows for only one rotor, i want to extend it to multi rotors and get the full streamline diagram of the whole quad-copter. I am not actually from aerodynamics field that's why it is little difficult for me to work it on my own although i have tried much. Also the picture shows flow diagram for vertical plane only, what i want is for horizontal plane also. That means i want flow diagram if observed from top plane. Hope this makes some sense. Commented Feb 25, 2016 at 4:46