Linked Questions

44
votes
3answers
16k views

Why does supersonic flight detach airflow from a wing?

I've read in several answers to questions that when a wing passes the speed of sound the airflow will become detached from the craft towards the rear quarter of the wing (thus making things like ...
25
votes
2answers
6k views

How do insects decrease aircraft performance?

Is it true that insects hitting the fuselage could decrease aircraft performance and increase fuel consumption? Insects are small in mass. I think even a large amount of them accumulate on the ...
18
votes
3answers
30k views

What is a vortex generator?

I saw a vortex generator mentioned in an aircraft listing. What is a vortex generator?
14
votes
2answers
5k views

Is airflow ever laminar in the boundary layer, near the wing leading edge?

I often see images of the boundary layer over a wing indicating the airflow is laminar over the first portion of the wing: Transition from laminar to turbulent flow over the wing. Left: source, right:...
9
votes
3answers
2k views

Aerodynamic advantage of blunt noses and WHY (subsonic)

Compared to a sharper conical nose, a blunter conical nose is aerodynamically superior in subsonic flight. My question is why. I've read a lot about this and allegedly: A blunter nose accepts a wider ...
8
votes
1answer
8k views

How does Reynolds Number affect skin friction drag?

I'm an aerospace engineering student, and I'm worried about efficiency as it relates to high and low Reynolds numbers. I don't understand which is more helpful for a aircraft. On a website I read ...
5
votes
1answer
1k views

Does skin friction drag decrease with velocity?

The wings of subsonic planes have usually a very low surface area and aspect ratio as big as possible. However, in supersonic aircraft, wings with more wetted area (e.g delta wings) are used. Is this ...
8
votes
1answer
1k views

When should I use the global Reynolds number and when the local Reynolds number?

I know that for the wing, the Reynolds number is based on the MAC. This makes sense to me, as the boundary layer develops along the length of the wing. However, what kind of Reynolds number needs to ...
8
votes
1answer
502 views

Can a Kline-Fogleman airfoil be used for engine turbines?

I am currently working on the Kline-Fogleman airfoil for NACA 23015 variant at Reynolds number 208800 with the configuration of the backward facing step of 50% thickness at 50% chord on the bottom ...
4
votes
1answer
917 views

What type of flow is preferable for jet engines?

I would like to know how laminar/turbulent flow affects engine performance. Any additional thoughts on the topic, even if not strictly related to the main question, are welcomed.
3
votes
1answer
544 views

How to maximize your practical lift/weight ratio in a multirotor?

My friend and I are currently working together in a multirotor competition. He's an experienced flyer and I'm more of a numbers guy (though my background is in software engineering, not aviation). ...
4
votes
1answer
262 views

Has research into the aerodynamic properties of non-smooth surfaces suggested any promising directions for future aircraft design?

As you might gather from Can planes benefit from Mitsubishi's Air Lubrication System? I'm interested in what possibilities there are for radically different approaches to aircraft body surfaces. ...
3
votes
1answer
92 views

Can surface roughing effects on an airfoil Reynolds number be quantified?

I am building balsa free flight gliders with a chord of 0.10 meters and a velocity of around 3 meters per second. This works out to a Reynolds number of around 15,000. The wings are around 1 meter ...
3
votes
0answers
249 views

What typical improvements in lift/drag are gained using dimple & zig-zag strips? [duplicate]

A golf ball goes twice as far using a dimpled surface. Many European aircraft (especially gliders) use dimple strips or zig-zag tape on propellers, wings, struts etc. Very few US aircraft use these ...
0
votes
1answer
87 views

What provides a higher lift to drag ratio, a thick laminar wing or a thinner wing with a vortex generator

Recent readings have shown the benefits of "boundary layer tripping devices" or vortex generators for reducing drag and maintaining attached air flow at higher angles of attack. It seems these ...