Laser bird protection (split from Idea for jet engines, who to contact?)

[Nlertn]

Due to the recent bird strikes on jet engines. What if the intake of a jet engine has a weak laser barrier that cuts the birds into smaller pieces to comply to the standard digestion specifications to avoid large birds from damaging the blades. The lasers can be just enough to cover the intake, and turned off when the plane is above a higher altitude to avoid laser diversion due to atmospheric changes. Do you think this is an option?

[exchemist]

2 hours ago, Nlertn said:

Due to the recent bird strikes on jet engines. What if the intake of a jet engine has a weak laser barrier that cuts the birds into smaller pieces to comply to the standard digestion specifications to avoid large birds from damaging the blades. The lasers can be just enough to cover the intake, and turned off when the plane is above a higher altitude to avoid laser diversion due to atmospheric changes. Do you think this is an option?

No.

And can you refer me to an example of a "digestion specification"? I am unfamiliar with this term. 

[TheVat]

7 hours ago, exchemist said:

No.

And can you refer me to an example of a "digestion specification"? I am unfamiliar with this term. 

Max size of object that can go into the turbofan safely.  Agree, a "weak laser" cannot mince birds in advance.  About as feasible as installing a sushi chef in front of each engine.  

[swansont]

A weak laser isn’t going to slice up a bird, and a strong laser (even a weak one, really) is an eye hazard to anyone looking out the window

[studiot]

Amongst other things my brother worked on the RB211 jet engine development.

I remember him telling me how they used frozen chickens, fired from a cannon into the intake, to test the impact resistance of jet engines.

[Genady]

14 minutes ago, studiot said:

they used frozen chickens, fired from a cannon into the intake, to test the impact resistance of jet engines.

I heard this story ~50 years ago, but rather as a joke like this:

Quote

The US Federal Aviation Administration has a unique device for testing the strength of windshields on airplanes. The device is a gun that launches a dead chicken at a plane's windshield at approximately the speed the plane flies.

The theory is that if the windshield doesn't crack from the carcass impact, it'll survive a real collision with a bird during flight.

It seems the British were very interested in this and wanted to test a windshield on a brand new, speedy locomotive they're developing.

They borrowed FAA's chicken launcher, loaded the chicken and fired.

The ballistic chicken shattered the windshield, broke the engineer's chair and embedded itself in the back wall of the engine's cab. The British were stunned and asked the FAA to recheck the test to see if everything was done correctly.

The FAA reviewed the test thoroughly and had one recommendation:

"Use a thawed chicken."

Anyway, The Chicken Cannon | Snopes.com rates this story a legend.

[exchemist]

1 hour ago, studiot said:

Amongst other things my brother worked on the RB211 jet engine development.

I remember him telling me how they used frozen chickens, fired from a cannon into the intake, to test the impact resistance of jet engines.

I guarantee a frozen chicken would wreck a turbofan. Even a (defrosted, soft ) crow can be enough: 

 

 

1 hour ago, TheVat said:

Max size of object that can go into the turbofan safely.  Agree, a "weak laser" cannot mince birds in advance.  About as feasible as installing a sushi chef in front of each engine.  

Is there an actual spec for that?

Edited January 4 by exchemist

[MigL]

Modern turbofan engines pass 90 % of the airflow through the single stage fan.
the core is essentially used to spin the turbines that drive the massive fan.
the previous smaller straight blade fans were of honeycomb titanium construction, while newer ones are hollow titanium or CMC (ceramic matrix composite ) construction, wide bladed and convoluted 'scimitar' shaped to allow for supersonic tip speeds.

They are not bird strike resistant, but rather 'tolerate' ( to some extent ) bird damage.

Now we all know why Rolls Royce almost went bankrupt in the early 70s, while developing the RB-211.
It was Studiot's brother's fault 😄 .

[swansont]

2 hours ago, exchemist said:

Is there an actual spec for that?

NIST standard sushi chef for civilian applications. There might be a milspec sushi chef, but that would be classified. The SI unit is the benihana

[exchemist]

1 minute ago, swansont said:

NIST standard sushi chef for civilian applications. There might be a milspec sushi chef, but that would be classified.

Heh heh.😄

27 minutes ago, MigL said:

Modern turbofan engines pass 90 % of the airflow through the single stage fan.
the core is essentially used to spin the turbines that drive the massive fan.
the previous smaller straight blade fans were of honeycomb titanium construction, while newer ones are hollow titanium or CMC (ceramic matrix composite ) construction, wide bladed and convoluted 'scimitar' shaped to allow for supersonic tip speeds.

They are not bird strike resistant, but rather 'tolerate' ( to some extent ) bird damage.

Now we all know why Rolls Royce almost went bankrupt in the early 70s, while developing the RB-211.
It was Studiot's brother's fault 😄 .

Does the RB 211 have these features, or is it one the older type? I ask because the plane in the video I posted did apparently have RB 211 engines, one of which is taken out by a fairly small bird, a crow or blackbird or similar, by the look of it.

[MigL]

4 hours ago, exchemist said:

Does the RB 211 have these features, or is it one the older type?

The RR RB-211 was developed over 50 years ago by Rolls-Royce to power the Lockheed Tristar, a 1970s competitor to the McDonnel/Douglas DC-10. Both were three engined designs, with two underwing engines and the third under the vertical tail.
Rolls-Royce struggled to deliver engines capable of 40,000 lbst in time for the launch of the aircraft, and almost went broke, but later versions of that engine were capable of nearly 60,000 lbst. They are however still several generations old, and Rolls' newest engines, while still based on the three shaft design of the RB-211, are beasts producing well over 90,000 lbst ( Trent 800 series ).
The latest off the drawing boards is the Ultra Fan, which is a totally new design that, instead of using three shafts to optimize efficiency of different compressor stages, uses a geared fan approach similar to the Pratt & Whitney of much less thrust.

This may be more pertinent to the discussion 

 

Edited January 5 by MigL

[exchemist]

8 hours ago, MigL said:

The RR RB-211 was developed over 50 years ago by Rolls-Royce to power the Lockheed Tristar, a 1970s competitor to the McDonnel/Douglas DC-10. Both were three engined designs, with two underwing engines and the third under the vertical tail.
Rolls-Royce struggled to deliver engines capable of 40,000 lbst in time for the launch of the aircraft, and almost went broke, but later versions of that engine were capable of nearly 60,000 lbst. They are however still several generations old, and Rolls' newest engines, while still based on the three shaft design of the RB-211, are beasts producing well over 90,000 lbst ( Trent 800 series ).
The latest off the drawing boards is the Ultra Fan, which is a totally new design that, instead of using three shafts to optimize efficiency of different compressor stages, uses a geared fan approach similar to the Pratt & Whitney of much less thrust.

This may be more pertinent to the discussion 

 

Haven’t watched the video, as the picture shows something that would be insanely dangerous - and is thus clickbaitily misleading, as it is clearly not what is done.

 

I presume the purpose of destructive tests of this type is to ensure failures of the rotating assemblies are contained safely by the casing. Not to see if the engine can withstand the insertion of the foreign object - which obviously it cannot. 

[toucana]

In the case of the recent disaster at Muan airport Korea on Sunday 29 December 2024 (involving Jeju Air Flight 2216) it would appear that the starboard engine *did* survive the initial bird strike, and was still developing some thrust as the plane made a wheels up landing.

https://www.bbc.co.uk/news/articles/ckgzprprlyeo

Video taken from the ground on the plane’s initial approach shows a large puff of white smoke and flame from the #2 engine which was evidence of a compressor stall caused by bird ingestion. Another video taken a couple of minutes later as the plane made a belly landing shows a heat haze from the #2 engine and the thrust reverser cowl deployed as well, whereas the port #1 engine is dead.

What seems to have happened is that the crew inadvertently shut down the wrong engine while responding to the initial bird-strike, which left them flying with only the damaged starboard engine still developing any thrust, and with no time or height to restart the port engine. As the crew had already retracted the landing gear and flaps to fly a go-around, shutting down the wrong engine also had the disastrous effect of taking out the hydraulic pump driven by the port engine which powers the landing gear. They couldn’t get the gear down again !

The plane type was a Boeing 737-8AS fitted with two CFM International CFM56-7B engines.

https://en.wikipedia.org/wiki/Jeju_Air_Flight_2216

These are high-bypass turbofan engines.