Aerofoils in heavy rain
Joined: Sep 2010
Aviation Qualifications: ATPL
Posts: 886
Likes: 235
From: by the seaside
Bug wipes.
I've seen a set that used a metal sail to track out to the wing tip and then tacked back in.
Had a phoebus c - first generation glass - had a small performance change with wet wings whereas on a K13 - tube and fabric - it was much more pronounced especially when I tried a loop - twice - and fell over the top.
I've seen a set that used a metal sail to track out to the wing tip and then tacked back in.
Had a phoebus c - first generation glass - had a small performance change with wet wings whereas on a K13 - tube and fabric - it was much more pronounced especially when I tried a loop - twice - and fell over the top.
Joined: Oct 2008
Posts: 116
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From: united states
On this I will comment (Not A Pilot)
Are you saying that Nasa also "has pretty bad reputation in scientific circles."?
More to the point, however, having taken the time to read D.P. Davies book (and interviewed some pilots on the subject at hand, among others) and also being very mathematically/scientifically well trained; Davies is not shown to be wrong either by the non-peer reviewed article or the of slightly higher quality article, by NASA.
Joined: Jun 2009
Posts: 1,344
Likes: 80
From: Bedford, UK
On why size and enegetics might matter
http://webs.wichita.edu/depttools/de...AA-AR05-42.pdf
Still pondering effect of water on properties of air; aero and thermodynamically. Don't wait up expecting an answer anytime soon.
http://webs.wichita.edu/depttools/de...AA-AR05-42.pdf
Still pondering effect of water on properties of air; aero and thermodynamically. Don't wait up expecting an answer anytime soon.
Joined: Mar 2003
Aviation Qualifications: ATPL
Posts: 2,558
Likes: 155
From: BC
Mr Optimistic;
It is always a hazardous enterprise when a pilot, untrained in the field, enters the arena of the engineer but that doesn't stop questions!
The question of droplet break-up is, (I sense) different than the question of how water behaves at, and more importantly affects the boundary layer.
I recognize that answers aren't easy or perhaps even available (as per your caution!), but the question in the paper that is being addressed is the character of droplet breakup and I believe many are curious how that relates to effects upon airflow, (aerodynamics), specifically, (the question being considered here is), does heavy rain affect the airfoil stall speed and if so how? As mentioned in the thread by someone, wing-loading at a critical time is going to change that behaviour which may be the reason we don't see the material effects, (stalls, etc), of heavy rain very often.
Still pondering effect of water on properties of air; aero and thermodynamically. Don't wait up expecting an answer anytime soon.
The question of droplet break-up is, (I sense) different than the question of how water behaves at, and more importantly affects the boundary layer.
I recognize that answers aren't easy or perhaps even available (as per your caution!), but the question in the paper that is being addressed is the character of droplet breakup and I believe many are curious how that relates to effects upon airflow, (aerodynamics), specifically, (the question being considered here is), does heavy rain affect the airfoil stall speed and if so how? As mentioned in the thread by someone, wing-loading at a critical time is going to change that behaviour which may be the reason we don't see the material effects, (stalls, etc), of heavy rain very often.
Joined: Jun 2009
Posts: 1,344
Likes: 80
From: Bedford, UK
Yeah I realised it was peripheral but to me it did highlight a lack of observed effect or even curiosity about the effects of adhering water. As it cant sustain shear, unlike ice, aater would seem a poor candidate for change of aerofoil characteristics. I did wonder why I never came across any discussion of saturation or water loading in any discussion. Perhaps it just reflects the tendency of engineering to address practical issues ie this isn't a significant effect. Should change the physics and equations of state though. I'll have a chat with the modellers but they tend to be rather led by the models rather than otherwise.
Joined: Oct 2008
Posts: 116
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From: united states
At The End of The Day
It evens out for regular in air flight. I do not place all faith in wind tunnels and I am not referring to take offs and landings either. As good as wind tunnel experiments can be, they still miss mediating/moderating variables and the balancing forces of actual nature.
