Linked Questions

49 votes
3 answers
21k 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 ...
Jae Carr's user avatar
  • 24.1k
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 ...
TBBT's user avatar
  • 1,842
19 votes
3 answers
33k views

What is a vortex generator?

I saw a vortex generator mentioned in an aircraft listing. What is a vortex generator?
Bassinator's user avatar
  • 5,490
16 votes
2 answers
10k 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:...
mins's user avatar
  • 71.8k
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.
Aircraft Enthusiast's user avatar
11 votes
3 answers
6k 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 ...
Aerocurios's user avatar
8 votes
1 answer
13k 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 ...
Volkan Aydıngül's user avatar
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 ...
sroger13's user avatar
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 ...
user15037's user avatar
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 ...
ROIMaison's user avatar
  • 7,157
9 votes
1 answer
615 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 ...
Archana Choudhari's user avatar
4 votes
1 answer
2k 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.
user15037's user avatar
3 votes
1 answer
475 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 ...
Robert DiGiovanni's user avatar
4 votes
1 answer
492 views

Why XFOIL predicts a lower drag coefficient at higher Re?

A well known idea is that for aerodynamic/streamlined bodies the friction drag is larger than pressure drag. Hence, a laminar boundary layer is preferable (only looking at minimal drag, no other ...
lWindy's user avatar
  • 181
5 votes
1 answer
349 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. ...
Daniele Procida's user avatar

15 30 50 per page