Engine types. Which is "better"?

[flying dog]

Ok, 3 "types".

 

1 - Steam

 

2 - Piston (internal combustion)

 

3 - Jet.

 

I appreciate when you don't have Piston (internal combustion) engines it is kind of difficult to use them, but......

 

From what I remember they got steam engines up to 25% efficiency.

 

How efficient are piston and jet engines at getting "bang for your buck"?

 

Cars have piston engines only because (again) they didn't have jet engines around.

 

Piston engines have many MANY moving parts. Jets have few. Less things to break - kind of.

 

I know they tried cars with jet engines, but I think they were going about it in the wrong way. (Eg: Bat mobile).

 

Instead of using the jet to directly drive the car, why not do like the trains to and use the "engine" to drive a geny (generator) and produce electricity and drive the wheels with an electric motor?

 

I had better stop there before I get on a soap box and .....

 

Ooops.

 

 

[facthunter]

Choice.

 

FD, the only suitable one of the three that you list for our operations , is the internal combustion engine. Specifically the "piston engine"., as the jet engine is also an internal combustion engine.

 

Even though I hate it for it's self-destructing tendencies, it ( the piston engine) is by far the most economical at low altitudes. A good version of the "wankel" should be a good sportplane engine also as it has the type of reliability that suits aircraft, for a small decrease in fuel efficiency.

 

A jet engine uses a hell of a lot of fuel at low altitudes and can cost a lot to build.

 

Steam .(You're not serious are you)? The latent heat of vapourisation of water ensures a poor efficiency thermally and it is sure to be heavier than the others.

 

Maybe a hydrogen engine converting to electricity directly, might be a possibility for the future, but perhaps not using compressed hydrogen as the tank would weigh a fair bit.

 

Think we're stuck with our "clunkers" for a while Nev..

 

 

[flying dog]

Nev,

 

Sorright.

 

I was only thinking. Yeah, I have been told that is dangerous.

 

Yeah, a wankel engine would be a good idea. Less moving parts there too. Forgot about that one.

 

Thanks.

 

 

[Tomo]

Hydrogen engines are a fascinating thing... There are so many factors to consider it is quite time consuming and difficult!

 

I've run a wipper snipper 25cc engine off Hydrogen, I've also run a glass bore single cylinder experimental motor off the Hydrogen as well... makes for a nice clean explosion anyway! It is just extremely hard to regulate how much of it to put in to make it work, not enough and it will fire every now and then, to much and it basically floods the engine and does nothing sensible.

 

Just to let you know FD - in a piston combustion engine we usually only get about 33% power out of what we put in.

 

 

[Powerin]

Hydrogen engines are a fascinating thing... There are so many factors to consider it is quite time consuming and difficult!I've run a wipper snipper 25cc engine off Hydrogen, I've also run a glass bore single cylinder experimental motor off the Hydrogen as well... makes for a nice clean explosion anyway!

Hey Tomo...experimenting with hydrogen power...that sounds cool! Where did you get the hydrogen from (make it yourself?) and how did you get the fuel/air mixture into the engine?

 

Like Nev, I think a hydrogen (or perhaps ethanol) fuel cell driving an electric motor might be the way of the future.

 

Peter

 

 

[Tomo]

Hey Tomo...experimenting with hydrogen power...that sounds cool! Where did you get the hydrogen from (make it yourself?) and how did you get the fuel/air mixture into the engine?

I knew I'd spark a bit of interest!!?

 

Yeah made it myself. Have been fiddling with it for quite some time now, have attached it to a few vehicles also, as a Hydrogen supplement/additive to the fuel/diesel for a reduction in fuel and exhaust emissions - though I mainly was interested in less fuel usage!

 

I haven't done much lately though, due to flying and been pretty busy.

 

Successfulness in less fuel usage was dependent on the vehicle, likes of my bush bash Nissan Pulsa was hugely different in more power! didn't actually do any fuel tests on it, but it made it twice as powerful so I'm guessing it would have been alright. Whereas my brother's 89 BMW made the fuel economy worse... It worked great on older Carby engines rather than the modern fuel injection ones. That is with hydrogen supplement.

 

 

[skydog]

Diesel

 

Diesel would be a good way to go for economy and power.

 

Shame Theirlert went bust.

 

 

[Powerin]

Have been fiddling with it for quite some time now, have attached it to a few vehicles also, as a Hydrogen supplement/additive to the fuel/diesel for a reduction in fuel and exhaust emissions - though I mainly was interested in less fuel usage!

I talked to a farm inventor at the Henty Field Days last year who was showing a system in an old Subaru (?) ute using an electrolysis unit to split hydrogen from water and then using it as a fuel supplement.

 

I was sceptical because it takes more energy to split water into hydrogen and oxygen than you get back out of burning it. But he claimed he was using the hydrogen/oxygen as a combustion enhancer and was getting incredible fuel economy. Sounds like the same thing you are doing.

 

Skydog: Thielert have been re-born as "Centurion Aircraft Engines" and are back in business. Diamond Aircraft now produce their own "Austro" diesels based on the same Mercedes engines. There are a few other interesting aero diesels in development...Wiksch, SMA and DeltaHawk come to mind. I think the 3 cylinder 100hp Wilksch has potential as a recreational aircraft engine. I have seen Youtube video of them in a few aircraft...but I must admit the rattling sound of a diesel just doesn't sound right in a plane!

 

Peter

 

 

[stanzahero]

Engines

 

Steam is an external combustion engine therefore it requires a pressure vessel to contain the energy (in this case steam). This is bad for at least two reasons:

 

1. extra weight, and

 

2. safety hazard - carrying a super heated canister under pressure at altitude creates more bad possibilities than just finding somewhere to stick it.

 

Wankel rotarys (Mazda, Suzuki, Morton, etc) have reliability issues because all the combustion pressure is kept in check by two apex seals and some flimsy looking side rings. These also tend to twist (the front and back rotor housings) if they are put under stress. Ever wonder why there are not many rotary racing cars?

 

I can't see CASA approving any hydrogen powered device flying in the near (or any) future because of Hindenburg type events...i_dunno

 

Just my opinion...

 

Stanzahero

 

 

[dazza 38]

Ok, 3 "types".1 - Steam

2 - Piston (internal combustion)

 

3 - Jet.

 

I appreciate when you don't have Piston (internal combustion) engines it is kind of difficult to use them, but......

 

From what I remember they got steam engines up to 25% efficiency.

 

How efficient are piston and jet engines at getting "bang for your buck"?

 

Cars have piston engines only because (again) they didn't have jet engines around.

 

Piston engines have many MANY moving parts. Jets have few. Less things to break - kind of.

 

I know they tried cars with jet engines, but I think they were going about it in the wrong way. (Eg: Bat mobile).

 

Instead of using the jet to directly drive the car, why not do like the trains to and use the "engine" to drive a geny (generator) and produce electricity and drive the wheels with an electric motor?

 

I had better stop there before I get on a soap box and .....

 

Ooops.

Hi all, jets engines IMO are out, because there they burn way to much fuel at low level.They work efficiently at high altitudes. Diesels are the go, but they are built relatively heavy, to combat the high compression.(please correct me tomo ,if i am leading people up the garden path since your a diesel mechanic). Rotarys from what i have read from articles can be a bit troublesome. Apparently it has something to do with having a very short, straight extremely rigid eccentric shaft (crankshaft) and a very high Q-component. (a frequency similar to a person holding a tone and breaking a glass ie- causing metal props to fracture.wooden and composite props are better suited.) Information sourced from american kitplanes magazine 1995. )Which to cut the story short, can effect stresses placed on the propeller/reducion drive. Although having said that, their are planes out their flying with rotarys.

[Guest check-in]

I just read today that Subaru now produce a boxer diesel engine. Turns @ over 4000 rpm so it sounds like it may be fairly light. Of course it would probably need a gearbox, but how heavy would such an installation be, compared with say a 4 cylinder Lycoming or Continental? Also would be great if it could be made to run on Jet A1 (less compression to do that?).

 

 

[dazza 38]

That sounds like a great engine. Is it 4 cylinder or six cylinder ?

 

 

[Guest check-in]

2.0 litre 4 cylinder with turbocharger. That's about all I know, other than it won't do for the Sonex (anything heavier than a Jab motor is too heavy).

 

 

[Tomo]

Diesels are the go, but they are built relatively heavy, to combat the high compression.(please correct me tomo ,if i am leading people up the garden path since your a diesel mechanic)

Yes that's pretty much the reason for it, also the extra heat created from higher pressure - and torque loadings on cranks would also be a problem. Not sure if you've ever pulled a diesel or petrol apart, but the crank size in a diesel is about 2-3 times the size of a petrol in most cases.

 

Diesel would be ideal if we can try and design one strong but light enough for the job, I'm sure they will in the near future...:thumb_up:

 

 

[wags]

There are certified diesel aero engines available now.

 

Although they are not yet available in sizes for fitment in RAAus aircraft it will not be very long before they are. Have a look at these sites and you will find that diesels are going to be the new generation (my thoughts) in aviation especially once the US military stop requiring Avgas in 2013.

 

Centurion Engines

 

DeltaHawk Diesel Engines

 

At least 6 new Glastar Sportsmen 2+2 aircraft are currently being built with the 200 HP Delta Hawk diesel fitted.

 

Glasair Aviation

 

 

[dazza 38]

2.0 litre 4 cylinder with turbocharger. That's about all I know, other than it won't do for the Sonex (anything heavier than a Jab motor is too heavy).

Hi all, just read the sunday mail with the engine in a outback. It is 110kw and 350Nm of torque.Cheers