Linked Questions

47 votes
3 answers
19k 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 ...
  • 23.9k
25 votes
2 answers
7k 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 ...
  • 1,842
18 votes
3 answers
32k views

What is a vortex generator?

I saw a vortex generator mentioned in an aircraft listing. What is a vortex generator?
  • 5,430
15 votes
2 answers
9k 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:...
  • 68.6k
7 votes
2 answers
2k views

Why do planes employ vortex generators if the laminar flows exhibit a far lower skin friction drag than turbulent flows?

I am a student and still relatively new regarding fluid flows. Our professor asked this and I can't find a source to answer this question.
11 votes
3 answers
5k 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
1 answer
12k 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 ...
6 votes
2 answers
1k views

Why do wings prefer laminar flow if cd is lower for turbulent flows?

Can anyone please explain to me why we prefer to maintain laminar flow over wings, despite the fact that the overall coefficient of drag appears to reduce as the Reynolds Number increases? I have read ...
5 votes
1 answer
2k 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 ...
9 votes
1 answer
597 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 ...
8 votes
1 answer
2k 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 ...
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4 votes
1 answer
1k 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
1 answer
335 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 ...
5 votes
1 answer
334 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. ...
2 votes
1 answer
593 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). ...
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