Linked Questions

4 votes
2 answers
4k views

What is the use of saw-teeth present on the nacelle outlets of modern turbofans? [duplicate]

I've noticed that there are saw-teeth on modern jet engines such as the GEnx and the Rolls Royce Trent 1000. What is their purpose?
Madhav Sudarshan's user avatar
1 vote
1 answer
712 views

How does a normal aircraft exhaust nozzle (the base model) generates a lot noise? [duplicate]

How does a normal aircraft exhaust nozzle (base model) generates noise and, whats the difference between the operation of the normal base model of aircraft exhaust nozzle and the new design of ...
Ghaith SJ's user avatar
2 votes
0 answers
148 views

How do the chevrons on engine nacelles reduce noise? [duplicate]

The B787 has these chevron-shaped teeth on the exhaust port of its engines to reduce noise. And according to the answer to this question they will be incorporated into the new B737's Can anyone ...
TomMcW's user avatar
  • 28.6k
15 votes
3 answers
3k views

Do nacelles around aircraft engines help in reducing the engine sound?

I know that the nacelles around the aircraft engines are actually a housing and are generally lightweight and have may components like inlet cowl, fan cowl, etc., but do they help in reducing the ...
NitinG's user avatar
  • 6,889
14 votes
1 answer
7k views

Why do Boeing aircraft have serrated engine nacelles, but Airbus does not?

Why do Boeing's new generation of jets (787, 747-8, 777X, 737MAX) have serrated engine nacelles whilst Airbus' latest (A350, A320neo etc) do not? I understand that Boeing's nacelles reduce turbulence ...
Hamlet's user avatar
  • 175
9 votes
1 answer
2k views

Why does the chevron-shaped engine suffer losses in thrust performance?

From here I found out a lot about chevrons on the Boeing 787, but not enough to satisfy why it results in performance loss. My thinking was originally, if they are "cutting triangular holes" in the "...
DrZ214's user avatar
  • 17.8k
5 votes
1 answer
1k views

How much thrust do you lose by putting chevrons on a engine?

The chevrons on a 787 are there exactly to decrease a type of drag that makes the engine louder, but the chevrons form vortices causing more drag. How much thrust is lost from the vortices on the ...
Ethan's user avatar
  • 9,359
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
2 votes
1 answer
539 views

Which type of chevrons is applied on the B787?

Which type of chevron nozzle was applied on the B787? I'm really confused about whether if it's sawtooth or sine wave.
Ghaith SJ's user avatar
0 votes
1 answer
487 views

Relationship Between Aircraft Thrust and Jet Exhaust Velocity? [closed]

What is the relationship between aircraft thrust and jet exhaust velocity & thrust and mass flow. Actually, my question is how to reduce or decrease jet noise without decreasing the thrust ?
Selvakumar's user avatar
0 votes
1 answer
146 views

What type of engine sound suppressors are used in general aviation?

Today we were discussing about noise pollution and why aircraft engines considered one of the biggest contributors to producing high intensity sound and I thought are there any ways and/or methods ...
Ludwig T's user avatar
  • 389