I am watching the guardian starring kevin costner. I got it off of emule for free. emule is still the artful dodger's marketplace for seedless GM fruit. Let's see what kind of good stuff grows in the rebelicious sunshine. Beckon artsy fartsy and the av geek squad plz. I found hack 5.0 so far, what else is there? Specifically, I want to know if a C-130 is more efficient if it "cut's an engine". I think the system would have more dead weight and more wasted off-angle thrust. The only way it could be true is if the engines are very inneficient and are limited to high output on an innefficient airframe. Would seem obvious except for having heard of military industrial complex spending and car engines that cut off some cylinders for efficiency.(gimick?) I will only tolerate quips after I get answers.

2/23/2007 5:59:43 AM

Im not a pilot or an aerospace engineer, so i could be completely wrong.

My intital thought is that if the cargo plane was empty or lightly loaded, they could realistically fly on fewer engines.

2/23/2007 7:02:11 AM

i stopped reading when i didn't understand what the fuck you were talking about

2/23/2007 7:05:00 AM

holy shit wrong forum

[Edited on February 23, 2007 at 8:37 AM. Reason : damn pen input]

2/23/2007 8:36:56 AM

OK

My pops was a mechanic/ gunner on an aC-130.
1st they didn't have pistons
2nd jets never run efficiently.
3rd If you've ever seen one fly over they leave a faint black trail of partially burned fuel

so turning off the engines is probably smart while empty and not getting shot at.

2/23/2007 9:08:12 AM

ok but like in the movie there is a c130 out near a storm rescue site and some girl says "they're low on fuel" and this guy says "I dont care tell 'em to cut an engine". I just want to know if that's just hollywood bs like the goldfinger "skin needs to breathe" line. Regarding c130's thin black line, I can only imagine unburned fuel due to operating outside of design conditions. Such as max power for take off (ala low altitude observation), bird proof holyshit mode, top speed impress the spectators shenanigans, etc. BTW, jets are better than pistons. Actually, anything is better than pistons. Technology clings to dogma almost as bad as species do.

2/23/2007 9:30:33 AM

Who the fuck are you, and what are you, high?

Jesus how can anybody take this guy seriously. I know the answer and I'll be damned if I'm going to tell you.

2/23/2007 9:36:30 AM

^^

Jets are more efficient per lb but

E out vs E in typically isn't that great.
Especially on a turbo prop the compression ratio is horrible unless they have a centrifugal compressor stage.

2/23/2007 10:09:03 AM

what is a centrifugal compressor stage? All I need to know to recognize that pistons suck is that they go up and down. That takes alot of energy to reverse directions when something that keeps going would do better. Argue all you want, the bendy tree survives the flood and the oak tree breaks in half and gets carved into a boat for next time.

2/23/2007 11:22:23 AM

you have no energy knowledge at all

piston engines have friction and inertia

but compression ratio determines the efficiency of the explosion

2/23/2007 11:29:05 AM

hahahah

2/23/2007 11:36:38 AM

someone is getting pwnt here

2/23/2007 12:00:17 PM

prolly still gotta feather the engine, sitting prop throws up alotta drag on that side.

2/23/2007 12:16:14 PM

Quote :

"All I need to know to recognize that pistons suck is that they go up and down. That takes alot of energy to reverse directions when something that keeps going would do better. Argue all you want, the bendy tree survives the flood and the oak tree breaks in half and gets carved into a boat for next time. "

Looky here, scrotard. A goddamn C130 has 4 turboprops. TURBOPROPS. Which use gas turbines (of the freewheeling, divorced power turbine variety). There are NO FUCKING PISTONS TO RECIPROCATE.

Furthermore, there is no way the plane can fly as efficiently on three engines at 75% to 100% cruise power (even if lightly loaded) as it can on 50 or 60 percent cruise power with all four. You have got to consider that there are laws of diminishing returns, especially dealing with free-air fluid flows across propeller blades and friction-producing mechanicals like gearboxes.

More on this later. I have important work to do, and this is not it.

BTW, they also run at a constant speed. You vary torque by varying the pitch on the prop. That and the divorced power turbine ensure that the compressor maintains optimal efficiency, and if it has a centrifugal compressor, then yes, it's much more efficient than the axial flow.

[Edited on February 23, 2007 at 12:20 PM. Reason : prop.]

2/23/2007 12:17:42 PM

scrotard? nice dan

2/23/2007 12:18:58 PM

GG dan i forgot about constant speed drives.... spent too much time around a 172

2/23/2007 12:26:38 PM

Quote :

"i stopped reading when i didn't understand what the fuck you were talking about"

2/23/2007 3:15:33 PM

-I don't know, but I have experience in several multiengine aircraft, and I've never heard of intentionally cutting an engine for fuel purposes.

-who said anything about pistons (although for the record, yes, they are a turboprop)

Quote :

"BTW, jets are better than pistons. Actually, anything is better than pistons."

not necessarily

Quote :

"what is a centrifugal compressor stage?"

it is an antiquated jet engine design. all modern jets that I know of strictly use axial compressors. a centrifugal compressor is like the cold side of a turbocharger, or a leaf blower, or a box fan, etc.

Quote :

"All I need to know to recognize that pistons suck is that they go up and down. That takes alot of energy to reverse directions when something that keeps going would do better."

you're oversimplifying. for example a rotary (Wankel) type engine does indeed make better specific output, but its fuel efficiency still sucks. there are more factors at work than you are accounting for.

Quote :

"prolly still gotta feather the engine, sitting prop throws up alotta drag on that side."

yeah, an unfeathered, windmilling prop is THE worst thing you can have in terms of drag.




_____________________________________________________
and if you're gonna talk out your ass, at least do it in English.

2/23/2007 4:31:17 PM

most small dual engine (prop not jets) planes if you lose a motor and don't feather it almost immediately you're pretty much dead....
i doubt that would happen with a 130.

2/23/2007 4:37:56 PM

a lot of turboprops hold the prop unfeathered with oil px, and if the engine fails or is shut down, it automatically feathers.

2/23/2007 4:45:53 PM