Putting Wings or Winglets on a Mavic?

[AlanTheBeast]

According to the article linked here Putting Wings or Winglets on a Mavic? airfoil arms reduced drag by 60%, so I guess the answer would be 'all of the above.'

The way those winglets are designed would be more effective at low speeds - which likely suits the mission of that drone. Further the increase in endurance also includes improvements from reduced weight.

While such arm shapes would be an improvement for Mavic, the afore mentioned drag when the MP is in forward flight, nose down, is really where there is huge drag penalty for the Mavic. Such arms would also have been an unwelcome packaging challenge for what the MP engineers were tasked to do: make a compact folding drone for US$999 retail.

 

[Gernby]

Certainly.
View attachment 7344
Angles are wrt the laser line.

I haven't been following this forum for a long time, but this topic came to mind when I heard about the Mavic Platinum's longer hover times. Has anyone done a side-by-side comparison of the front / rear prop angles to see if they are any different with the Platinum? I suspect that they are different.

 

[Xtreme Drone Pilot]

I think the increased lift of a moving prop has to do primarily with a simple fact of aerodynamics that the lift of a lifting surface (at a fixed angle of attack) is proportional to the square of airspeed. Consider two equal, equidistant areas on the opposite blades of a prop, let their linear velocity be V, and the drone is moving at the speed U; then the area moving forward produces lift proportional to (V+U)^2, the area on the other side produces lift (V-U)^2. So, when drone is hovering, we have total lift V^2+V^2 = 2*V^2, while when it's moving, we have (V+U)^2+(V-U)^2 = 2*V^2+2*U^2 - i.e. we have additional 2*U^2 of lift!

Now, of course, the same applies to drag, so the overall efficiency increases to the max at some speed and then the drag losses overweigh the benefits - so, as typical in many efficiency-vs-speed scenarios, it's a bell-shaped curve.

 

[Fleamavic]

I would bet that we could come up with many ways to prove that the MP is nose heavy, but thankfully, it seems we agree it is. However, another factor that I just noticed is that the front props are pitched toward the rear a few degrees, but the rear props are not. I suspect the pitch in the front motors is required to offset the heavy nose.

Perhaps it would be better - though more complicated design-wise I guess - to pivot the motors instead of lift the back/raise the front. On that note, I also wonder if to achieve forward flight the back comes up or the front goes down..? Any of you engineers know that? Would it be marginally more efficient over time in cases where there are lots of acceleration changes to have the front drop vs the back rise?


hmmmmm..
FM

 

[Fleamavic]

Let me make it simpler. AlanTheBeast is stating this (with my wording): Imagine flying a waterproof helo, under a column of falling water (a waterfall). Yes of course it would get knocked out of the air. But IF it could fight back, with more power, it would hover in the waterfall. In real life an impossibility due to the mass of water. But think of how much power it would require!

Now replace the water with air. You fly under a downrush of air, an "airfall". This pushes the entire aircraft down. To compensate you add lift (more thrust). This is possible because air is so much less dense than water.

AlanTheBeast and rydfree, in their own ways, are both saying that while hovering, the quad creates its own column of air, a "waterfall of air" that it is fighting. In moving foward, it is getting fresh, clean air into its props that has no downward momentum (that it has to compensate for), providing better lift at a given torque.

I'm no engineer.
I get the comparison, but when the machine is hovering, it is pulling the air downwards rather than having to fight air "falling" on it. Is there no difference between these two situations?

Thanks
FM

 

[Classic flyer]

As many of you may know, according to the official specs the Maximum Flight Time of a Mavic (=27 minutes) is actually longer than the Maximum Hovering Time of a Mavic (=24 minutes) by about 3 minutes or 12.5 %. That's a pretty significant amount. Apparently, the Mavic uses less energy when moving because the airflow around its body results in a bit of "body lift". So an obvious idea is whether it is possible to further enhance this lift by adding wings or winglets to a Mavic? The forward speed of a Mavic in non-sport mode is about 20 mph, which seems to be fast enough for wings or winglets to supply some significant amount of additional lift to a Mavic, thereby extending its flight time.

If just the Mavic's natural, un-optimized body shape can provide enough lift to extend the flight time by over 12 %, think about what carefully designed wings or winglets might be able to achieve. 20% or 30% or 50% or more extended flight time? Perhaps something we might see in a next-generation "Mavic 2"?

Fold out wings/winglets ...might be something to experiment with

 

[ruggb]

So what these 9 pages are saying is that when hovering the blades act like a fan and push air. the resulting "lift" is an action/reaction much like a rocket.
When the AC is moving thru air the blades are acting like a sail on a sailboat (airfoil) creating force vectors up and in the direction of motion.

It takes more energy to counter the air hitting the blade perpendicular (downdraft) than it does when air hits the blade at an angle.

So if all you wanted to do was hover, an aggressive flat fan blade would be best, pushing more air down and allowing the downdraft to hit the blade at an angle, reducing its downward force, like a prop on a power boat.

Do I have the right?

 

[Rockowe]

As many of you may know, according to the official specs the Maximum Flight Time of a Mavic (=27 minutes) is actually longer than the Maximum Hovering Time of a Mavic (=24 minutes) by about 3 minutes or 12.5 %. That's a pretty significant amount. Apparently, the Mavic uses less energy when moving because the airflow around its body results in a bit of "body lift". So an obvious idea is whether it is possible to further enhance this lift by adding wings or winglets to a Mavic? The forward speed of a Mavic in non-sport mode is about 20 mph, which seems to be fast enough for wings or winglets to supply some significant amount of additional lift to a Mavic, thereby extending its flight time.

If just the Mavic's natural, un-optimized body shape can provide enough lift to extend the flight time by over 12 %, think about what carefully designed wings or winglets might be able to achieve. 20% or 30% or 50% or more extended flight time? Perhaps something we might see in a next-generation "Mavic 2"?

This is a Fascinating idea-
Maybe DJI could use this idea for further Iterations:

A Wing gives you Energy Free Lift - that's why Planes are so much more efficient than helicopters.

See the Parrot DISCO for example (Battery lasts Way Longer and faster speeds easier to attain ….

Discussion
Indeed a large wingspan would probably help (to) cut the need for for the Large downward thrust and the wings Most likely would sustain the craft in forward flight - with the Glider effect...
I assume the need for high rotor speed could be reduced in forward flight only - as long as: - --

1) the 'Wings' are trimmed to STRAIGHT and LEVEL or slightly (elevator) UP position (as a helper for lift) - The Drones Firmware is designed to Maintain the Altitude in straight flight - ...You don't want the craft to be made Counteract to PUSH HARDER if the wings are tilted to go down (as a Planes elevator)

2)the 'Wings' do not interact with the Downward Push of the Props - Obviously

3) Sidewise sensors should be deactivated - (which they are in P & S mode) -

4) there should be Struts to hold the wings - (maybe strong Light weight Metal)
… the wings ~ like from a hobby shop Glider Design (Polystyrene)

5)Important - the Struts Would need to turn the wings to compensate for DISH Angle of attack - so the wings are not forced into the (to go down position) in forward flight- (maybe with Servo's)
So Like the Camera View - the Struts Keep the WINGS Horizontal to the ground...

A quick drawing (Excuse the non-Precision)



Adjustment for forward Flight

 

[Rich Sugden M.D.]

It's not the "body" giving additional lift ... it is "translational lift" experienced by all helicopters, single or multi-rotor ..Google it ...

 

[Rockowe]

It's not the "body" giving additional lift ... it is "translational lift" experienced by all helicopters, single or multi-rotor ..Google it ...

Yes - Helicopters get Lift from Moving forward - with the Dish as a Wing -
The OP''s point (I think) was that the aerodynamics of the body gives additional lift to the normal lift of transitional Lift of the rotors

But they ALSO can get additional Lift from an Aeroplane / Glider type Wing.

 

[ruggb]

I would bet the body does not contribute any lift. It is all from the rotors moving thru the air horizontally.