propellers

[tino.v]

I hope I could add a close-up of a Mavic Mini propeller.

As you can see, the letters and digits are raised significantly.
Isn't that bad for the aerodynamic flow of the wing ?

I used to fly sailplanes in the past and when bugs and flies were sticked on the wings, we had to clean them before flying, because it disturbed the airflow on the wing.

Your thoughts plse?

Regards

Tino

 

[EyesWideShut]

There's very little lift coming from the inner area on the props, it's all coming from the much faster spin towards the middle out to the tips so the airflow disruption should be minimal.

 

[FoxhallGH]

That part of the prop is all about brute-force deflection of the air that hits the piece of the prop blade with the most pitch.
There is some laminar flow of course, and you would get a slight performance/efficiency increase, but it would be hardly measurable! In fact, there may be some evidence to show that the 'disturbance' caused by the lettering, MAY improve the way that the air 'sticks' to the airfoil shape and reduces cavitation type effects [???]
Full-size aircraft often use small 'fence' plates near the leading edge of a wing, to keep laminar flow stable ...

 

[new2mavic]

ever heard of vortex generator ? those markings may do good ....

 

[FoxhallGH]

ever heard of vortex generator ? those markings may do good ....

View attachment 95314

That's what I was looking for ... Yes ...

 

[EyesWideShut]

To take this this thread a little off line, golf balls in the latter 1800's were made of a gutta-percha resin rounded into a smooth ball. It was quickly found that used ball with nicks and cuts flew further and were the idea behind dimples providing lift in modern balls.

 

[Rene Artois]

I fitted vortex generator to the rear edges of our motorhome to improve stability from crosswinds and when passing trucks.

 

[tino.v]

yes, but those fins are at the rear (thin part) of the wings, or at the end of the RV

Let's scale up things to the size of a real helicopter. What would you think when you see a helicopter with big raised letters on their propellers? Wouldn't you say : 'those are not very aerodynamic'.