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Roost Air Lounge => The Classroom => Topic started by: Frank N. O. on December 11, 2006, 03:33:43 AM

Title: More diesel questions
Post by: Frank N. O. on December 11, 2006, 03:33:43 AM
I've been thinking, I've heard here that most turbo airplane engines are normalized and not positively charged, but what about the diesel engines, are they running at reduced boost, and why does the airplane piston engines not use positive boost?
Speaking of diesel conversions, have you heard that Subaru is planning to make diesel engines, in boxer-form of course, and with help from Porsche, sounds very interesting indeed.

Btw, does anyone know of a low-level fly-by clip of a diesel plane? I've been wondering how one sounds, and how is the noise-level compared to a classic airplane engine?

I also wonder if MSFS can simulate a small automotive derived turbodiesel engine.

Frank
Title: Re: More diesel questions
Post by: undatc on December 11, 2006, 05:38:03 AM
dunno about the conversions or anything, but i can attest to the sound.

Personally i cant tell a difference, but maybe im not attuned to airplane sound.  Diamond runs diesels in their airplanes and they send a few up here to UND evey year for us to play with and abuse to see if we want to switch over.  From what i hear they are great engines, low fuel costs, great emmissions etc etc.

http://www.youtube.com/watch?v=XsZvVGyaKrk

here is a link to a 172 on diesel, not real good, but gives you an idea.
Title: Re: More diesel questions
Post by: Baradium on December 12, 2006, 08:24:59 AM
undatc, the only diamond factory availible with diesel engines is the twin star, which is a twin engine aircraft.

All their other aircraft are normal aircraft spark engines.   The 40s use lycomings and I want to say that the 20s use continentals (but they might be lycoming as well). 

So are they bringing twin stars by UND?

I'm not even aware of any of their singles that have been refit with diesels, although there may be one out there.  I don't believe diamond has explored that themselves yet though.
Title: Re: More diesel questions
Post by: undatc on December 12, 2006, 02:08:45 PM
Yea, they are twin stars, thought i said that but i guess i didnt.  We have the largest non military fleet in the world for aiplanes, so all the companines send up airplanes to play with.  We currently are running semionals but every two years "they" reevaluate to see if they want to switch, so every two years, brand new models, last spring we had two twin stars, like 4 diamond stars, a couple new 182's and 172's, sr20 and 22, and some other twin i cant remember.  We actually are supposed to be getting the first two VLJ eclipse 500's that roll off too, however it seems our order has been pushed back.  We are contracted with eclipse to provide training on them for pilots, so i assume they are gonna get a lot of flight time in the near future.

We also are home to NASA's DC-9  ;D  They have 'given' it to us for experiments and such, so its kinda weird seeing 70 warriors 30 arrows 30 semonals 15 sr20's our smattering of decathalons and cubs and then the DC9 sitting on our ramp.  We have a baron and ust to have a small lear jet, but ther meterology department crashed it up in alaska about a year ago.
Title: Re: More diesel questions
Post by: Gulfstream Driver on December 12, 2006, 05:08:23 PM
UND also had a couple of BeechJet 400's, but sold them after the Chinese students left.

Didn't know they were getting all of those cool aircraft.  Almost wish I was still there.  (almost)
Title: Re: More diesel questions
Post by: fireflyr on December 12, 2006, 11:56:52 PM
  We have the largest non military fleet in the world for aiplanes,
WHOOPS----maybe oughta check that out and qualify it ???
Title: Re: More diesel questions
Post by: undatc on December 13, 2006, 03:51:19 AM
WHOOPS----maybe oughta check that out and qualify it ???
Quote

We do.  At grand forks alone we have about 160 aircraft not including our fleet of helicopters, i think we have about 15 of them.  We also have satalite campuses around the nation in Phoenix, Honolulu, Spokane, Crookson, Lumberton, and Williston, each of which about about 20 aircraft each, so add that up and we have 175+(6x20) is about 295 aircraft.  Then you can also count the aircraft we lease out to other flight schools, i dont know exactly how many we do, but i know its quite a few.  So say about 360ish aircraft.  We also have an extension campus in Duluth that is teamed up with Cirrus to provide factory training with about 20 of our cirrus aircraft, so with that were up around 380 aircraft total system wide.

http://www.und.edu/president/reports/2005/info.html

If you go close to the bottom of the page it reads, "UND has the world's largest non-military training fleet of training aircraft."
Title: Re: More diesel questions
Post by: chuckar101 on December 13, 2006, 04:15:56 AM
I can verify the 20 aircraft at phoenix.  The planes aren't bad but the can't say the same for the students.   No offense to UND but the students here in phoenix can be a little scary.  But od cours they probably say the same thing about us ATP students so I'm really just blowing smoke out my ass.
Title: Re: More diesel questions
Post by: tundra_flier on December 13, 2006, 04:29:18 AM
I've been thinking, I've heard here that most turbo airplane engines are normalized and not positively charged, but what about the diesel engines, are they running at reduced boost, and why does the airplane piston engines not use positive boost?
Speaking of diesel conversions, have you heard that Subaru is planning to make diesel engines, in boxer-form of course, and with help from Porsche, sounds very interesting indeed.

Btw, does anyone know of a low-level fly-by clip of a diesel plane? I've been wondering how one sounds, and how is the noise-level compared to a classic airplane engine?

I also wonder if MSFS can simulate a small automotive derived turbodiesel engine.

Frank

I don't know about the engines Diamond is using, but I know some of the diesels that were being experimented with a few years ago for aircraft were 2 cycle diesels, like the old Detroits.  Those require positive boost to function well.

Phil
Title: Re: More diesel questions
Post by: fireflyr on December 13, 2006, 04:32:04 AM
WHOOPS----maybe oughta check that out and qualify it ???
Quote

We do.  At grand forks alone we have about 160 aircraft not including our fleet of helicopters, i think we have about 15 of them.  We also have satalite campuses around the nation in Phoenix, Honolulu, Spokane, Crookson, Lumberton, and Williston, each of which about about 20 aircraft each, so add that up and we have 175+(6x20) is about 295 aircraft.  Then you can also count the aircraft we lease out to other flight schools, i dont know exactly how many we do, but i know its quite a few.  So say about 360ish aircraft.  We also have an extension campus in Duluth that is teamed up with Cirrus to provide factory training with about 20 of our cirrus aircraft, so with that were up around 380 aircraft total system wide.

http://www.und.edu/president/reports/2005/info.html

If you go close to the bottom of the page it reads, "UND has the world's largest non-military training fleet of training aircraft."

I stand corrected and impressed |:)\ |:)\
Title: Re: More diesel questions
Post by: undatc on December 13, 2006, 04:32:54 AM
Never said we were the best pilots, actually a lot of guys that get their ratings outta here scare me, my self included, i can legaly fly a plane anywhere i want, but im no where proficient in flying and would definately be a danger to myself and others.  Also our satalite campusus kinda have a rep of being a lil shady....
Title: Re: More diesel questions
Post by: undatc on December 13, 2006, 04:34:50 AM
WHOOPS----maybe oughta check that out and qualify it ???
Quote

We do.  At grand forks alone we have about 160 aircraft not including our fleet of helicopters, i think we have about 15 of them.  We also have satalite campuses around the nation in Phoenix, Honolulu, Spokane, Crookson, Lumberton, and Williston, each of which about about 20 aircraft each, so add that up and we have 175+(6x20) is about 295 aircraft.  Then you can also count the aircraft we lease out to other flight schools, i dont know exactly how many we do, but i know its quite a few.  So say about 360ish aircraft.  We also have an extension campus in Duluth that is teamed up with Cirrus to provide factory training with about 20 of our cirrus aircraft, so with that were up around 380 aircraft total system wide.

http://www.und.edu/president/reports/2005/info.html

If you go close to the bottom of the page it reads, "UND has the world's largest non-military training fleet of training aircraft."

I stand corrected and impressed |:)\ |:)\

Hey no prob, sometimes I am wrong, if you want, here is a link to our aviation depatment, a lot of the number for instance the number of aircraft we have is old and outdated, but most of the stuff is the same.

[url]http://www.aero.und.edu/f1_Home/index.php (http://www.aero.und.edu/f1_Home/index.php)[/url]
Title: Re: More diesel questions
Post by: fireflyr on December 13, 2006, 04:48:08 AM
Guess I hadn't paid attention to the training programs available for quit a few years----Sure looks like UND and a few others offer comprehensive aviation programs--a very good thing indeed! |:)\
Title: Re: More diesel questions
Post by: Frank N. O. on December 13, 2006, 05:33:44 AM
I have heard of Detroit 2-stroke engines but not much more than the name since european truck companies make their own engines, Scania, Volvo, MAN, Mercedes etc. One problem with diesels though is that the automotive engines are mainly inlines and not boxers so even with smaller displacements I wonder how it can fit in a plane made for a boxer engine.

Diesels use the modern FADEC systems right? Does that mean that the mixture lever is obsolete then? And what about the cowl flaps for cooling control, are they still needed or is the water cooling taking care of itself?

Frank
Title: Re: More diesel questions
Post by: Mic on December 13, 2006, 08:17:14 AM
undatc, the only diamond factory availible with diesel engines is the twin star, which is a twin engine aircraft.

All their other aircraft are normal aircraft spark engines.   The 40s use lycomings and I want to say that the 20s use continentals (but they might be lycoming as well). 

Diamond is delivering directly from its factory Diamond DA40TD which is powered byt the diesel Thielert Centurion 1.7

We are (the flying school part of my Institute) using a dozen of this new aircraft. ( www.iaagepag.com )

I agree about noise reduction (helped by the low power applied on the 3 blades propeler : 135 HP instead of 180HP for the lycoming)

Just a remark : we're also operating the SOCATA TB20 (250HP, retractable landing gear, 4 places, metallic structure). Its cruise speed is 140 kts with an average consumption of 50 liters per hour

With the Diamond DA40 (135HP, fixed landing gear, 4 places, composite structure), we cruise at 130kts, 125kts at 70% burning only 19 liters of JET A1 (the Jet A1 is half the price of he AVGAS in France)
Title: Re: More diesel questions
Post by: chuckar101 on December 14, 2006, 01:48:32 AM
Never said we were the best pilots, actually a lot of guys that get their ratings outta here scare me, my self included, i can legaly fly a plane anywhere i want, but im no where proficient in flying and would definately be a danger to myself and others.  Also our satalite campusus kinda have a rep of being a lil shady....

Wasn't trying to be rude or anything, just saying what I saw.  Obviously there turning out decent students since we all use the same examiners here.  It is funy to see UND in Phoenix especially since there tucked into the far corner of the airport.
Title: Re: More diesel questions
Post by: Baradium on December 14, 2006, 04:02:58 AM
If you want to get technical, the first statement didn't say "training fleet" just "fleet."    There are airlines with much larger fleets.  ;)

UND is a big school though.   Wish MTSU had some of the options availible there, but on the other hand, I'm happy to have gone to a school with a smaller size to the aviation program.  We do have a 727 on our ramp... but it isn't going anywhere.  ;)

Diamond did have a prototype DA-42 with spark engines, supposed to have amazing single engine climb performance at low altitude due to the extra HP availible down low.  Report I read indicated that with a DA-40 redline they had to pull back power to stay below redline with the VSI pegged out because they were uncomfortable pitching back anymore on climbout (and these were test pilots).   Havn't seen any indication they are going to offer it now, although they'd been talking about making it an option to have the sparks instead of diesel.


Title: Re: More diesel questions
Post by: tundra_flier on December 14, 2006, 04:05:14 AM
I have heard of Detroit 2-stroke engines but not much more than the name since european truck companies make their own engines, Scania, Volvo, MAN, Mercedes etc. One problem with diesels though is that the automotive engines are mainly inlines and not boxers so even with smaller displacements I wonder how it can fit in a plane made for a boxer engine.

Diesels use the modern FADEC systems right? Does that mean that the mixture lever is obsolete then? And what about the cowl flaps for cooling control, are they still needed or is the water cooling taking care of itself?

Frank

Diesels don't have a mixture control anyway.  There's no throttle plate, the air induction system is just wide open all the time and power is regulated by how much fuel you pump into the cylinders.  If you use more fuel than you have air to burn you get the black sooty exhaust that old diesels were known for.

Phil
Title: Re: More diesel questions
Post by: undatc on December 14, 2006, 03:54:48 PM
One thing I dont think anyone has addressed though, is where do you get diesel on a ramp?

I know from my limited flying experience, you have 100LL and 110, and if youre lucky JetA at the smaller airports, but I dont think ive ever seen a tank of diesel sitting there.  I spose you just always just pull over to the mechanics bay and im sure they have a fuel caddy for their trucks, but this poses a problem for the average Private Pilot flying form podunk airport.  The bay may not always be open, and the airport youre going to may not have it either.  Do you always just carry some empty 10gal containers around and are ready to take a walk to the gas station or what?
Title: Re: More diesel questions
Post by: Gulfstream Driver on December 14, 2006, 04:41:59 PM
"Theoretically", your x-cntry planning should include airports with diesel available, I think.
Title: Re: More diesel questions
Post by: fireflyr on December 14, 2006, 06:42:24 PM
"Theoretically", your x-cntry planning should include airports with diesel available, I think.
There is a lot of difference between diesel and Jet A and the Thielert engines are designed to burn Jet A----wouldn't try pump diesel until I checked factory specs thoroughly ???
Title: Re: More diesel questions
Post by: undatc on December 14, 2006, 08:19:49 PM
"Theoretically", your x-cntry planning should include airports with diesel available, I think.
There is a lot of difference between diesel and Jet A and the Thielert engines are designed to burn Jet A----wouldn't try pump diesel until I checked factory specs thoroughly ???

Woah, so if i understand you right these diesel engines actually burn JetA and are just using the diesel type combustion principal?
Title: Re: More diesel questions
Post by: Baradium on December 14, 2006, 09:35:59 PM
"Theoretically", your x-cntry planning should include airports with diesel available, I think.
There is a lot of difference between diesel and Jet A and the Thielert engines are designed to burn Jet A----wouldn't try pump diesel until I checked factory specs thoroughly ???

Woah, so if i understand you right these diesel engines actually burn JetA and are just using the diesel type combustion principal?

Seems to be some misunderstanding going on here...

Diesel Engines don't neccessarily burn diesel fuel, it's a combustion process.  Yes, the aviation diesel engines are designed to run on Jet A.   However, any diesel engine will run on Jet A (which used to be called aviation kerosene).

It's not done this way anymore, but the flow for Jet A production used to be:  oil ---> Diesel fuel --> Kerosene --> Jet A

The thing is, Jet A is a lot more highly refined than Diesel fuel.  The modern diesel is probobly going to start getting a lot closer though with the change to ULSD (Ultra Low Sulfer Diesel).  What this leads to is that you can generally run Jet A in a Diesel engine without any ill effects, but an engine designed specifically with Jet A in mind miight not like diesel fuel becuase it'll essentially be "dirtier."

There is a question with modern Jet A about whether any new additives will harm seals in an engine not designed for it, but that's just theory and I've never heard of anyone having problems if they ran Jet A in their fuel trucks or other diesel vehicles on the ramp.


However, turbine engines don't actually *need* Jet A either.  In fact, they've had turbine engines running on anything from coal dust to powdered milk!  The problem with these is that you have to set up the burner to burn whatever fuel if it is a different form (such as powder).  We are allowed to run 100LL Avgas in our PT6s, although we are limited in how much power we are allowed to output with it (gasoline burns faster and hotter than Jet A or diesel fuel, gasoline tends to explode while diesel or jet fuel just tends to burn, this is why there have actually been instances of diesel fuel putting *out* fires because it actually isn't extremely easy to ignite like gasoline).


To further give you a headache, the first diesel engines didn't run on diesel fuel.
Title: Re: More diesel questions
Post by: fireflyr on December 14, 2006, 11:33:55 PM
There is no confusion------Thank you though for expounding on what was already stated 8)
Title: Re: More diesel questions
Post by: BrianGMFS on December 14, 2006, 11:36:29 PM
I pour the Jet A I sump out of our planes into the diesel tractors at work all the time.


Brian
Title: Re: More diesel questions
Post by: Baradium on December 15, 2006, 08:15:04 AM
There is no confusion------Thank you though for expounding on what was already stated 8)

Actually, the confusion was about the idea that a "diesel engine" is naturally *supposed* to run on "diesel fuel" just because it's called "diesel fuel."    ;)

Sorry for not being more clear.  I'm not even so sure now there was so much confusion anyway...   I was halfway thinking about work and then trying to be on the forum while waiting for my plane to get back from its previous run...  ;)
Title: Re: More diesel questions
Post by: Frank N. O. on December 15, 2006, 08:48:34 AM
To my knowledge, Diesel as well as Wankel (in USA perhaps better known as a rotary engine) is named after the last name of the person who invented it. The 4-stroke spark-ignition piston-engine normally called a gasoline engine is an Otto-cycle (I think that was the inventor's name as well). I also think I heard the term Brayton-cycle used with gasturbine engines. I actually think there's at least one more engine type with the inventor's name but I can't remember what it is, except it's not really used anymore. I think it was an engine-type used in early submarines.

Frank

P.S. Extra credit for those that can tell me what a Miller engine is, I know, but do you? :)
Title: Re: More diesel questions
Post by: Baradium on December 15, 2006, 11:03:56 AM
I do now... although I don't really think it should be considered it's own type of engine.  But that's just me.
Title: Re: More diesel questions
Post by: fireflyr on December 15, 2006, 03:45:52 PM
Googled it-----kind of interesting............and complicated :-\
Title: Re: More diesel questions
Post by: TheSoccerMom on December 16, 2006, 02:44:12 AM

P.S. Extra credit for those that can tell me what a Miller engine is, I know, but do you? :)

 ;D

I KNOW, I KNOW!!!!!!!!!  That's an engine that runs on Miller High Life, with mods for Miller Genuine Draft or Miller Lite.   ;)

Sheesh.  And mechanics think pilots are STUPID.  Hmmmpph!!   ::)
Title: Re: More diesel questions
Post by: Frank N. O. on December 16, 2006, 03:00:26 AM
LOL Soccermom that was a great one!
Actually it is true that it's not quite a seperate type of engine, but it is different than a std. Otto cycle engine but so far only one production car with such an engine was ever made to my knowledge, the Mazda Millenia in the late 90s.

Speaking of alternative engine parts then I'm intrigued by the rotary valves that the US company Coates makes.

Speaking of fuel control for diesels, does the FADEC system make sure you can't put in too much fuel when you come up into thin air, and how does it do it, is the throttle-lever on aviation-diesels a suggestion-stick and not a direct control like too many cars are using now?

Frank
Title: Re: More diesel questions
Post by: fireflyr on December 16, 2006, 05:48:03 PM

P.S. Extra credit for those that can tell me what a Miller engine is, I know, but do you? :)

 ;D

I KNOW, I KNOW!!!!!!!!!  That's an engine that runs on Miller High Life, with mods for Miller Genuine Draft or Miller Lite.   ;)

Sheesh.  And mechanics think pilots are STUPID.  Hmmmpph!!   ::)


Well DUH, talk about dumb!!!   I obviously googled the wrong site---I always wondered about those "MGD" stikers on the fuel caps :P
Title: Re: More diesel questions
Post by: Baradium on December 18, 2006, 12:18:36 PM
It's hard to generalize about "aviation diesels" since there are so few.

FADEC does everything on it's own.  Moving the lever in the aircraft is like moving the joystick on a computer, the computer controls fuel.

On these engines, the turbocharging keeps the pressure, as far as the engine is concerned, pretty constant.  The engine doesn't know you are changing altitude.
Title: Re: More diesel questions
Post by: Mic on December 23, 2006, 06:39:17 PM
About Thielert engines, it's allowed to use common diesel fuel instead of Jet A1 because the engine is originally designed for use on cars.

The only limitation is about the outside temperature : at low temperature (high altitudes) the diesel loose its fluidity carateristics and you must avoid these conditions because you encounter a filter clogging.
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