Future small aircraft engines.Wich way?

[Niels Abildgaard]

Hello Makoman

Glad You like the V2 aircraft scheme with central exhaust valve and stratified charge by moderate swirl.
Would You invest in that?

 

[makoman1860]

Hello Makoman

Glad You like the V2 aircraft scheme with central exhaust valve and stratified charge by moderate swirl.
Would You invest in that?

Invest? If you need design help I would be more than willing to assist with that. Send me a PM and I will give you my e-mail.

 

[Niels Abildgaard]

Hello Makoman

As I wrote in the first letter this is just an mental game while we wait for another put put fourstroke design.
Future aircraft propulsion systems will not come from neither America or Europe,but we are still allowed to dream and argue.Let us enjoy that.

 

[mu38&Bg#]

I've been following along here. What is the story with Delta Hawk? Are they viable? I would think that multi-fuel (at least the ability to use kerosene) is beneficial.

With the twin prop arrangement I would expect noise due to the proximity of the prop tips to the fuselage. Has this been tested or is tip speed low enough to minimize this?

Fuel consumption piqued my interest. I saw mention of the BMW IIIa at 180g/HP-hr (240g/kWh), but the published tests put it at 270g/kWh? O-320, O-360 is something like 255g/kWh.

It seems knock limited large bore low RPM engines are pretty well sorted. Where is the increased efficiency going to come from? There is an interesting reference to the turbo versions burning much more fuel here, at the bottom of the page. Bristol was working with mechanical direct injection of gasoline during WWII, did it ever become common? Germany also used it in some airplanes in production, I think.

Niels, have you read anything about this company? http://www.achatespower.com It seems they are investing a lot in the Junkers type.

I agree that everything in the engine world was done by WWII when turbines took over. There have been advances since then, but the cost is staggering for the gains. Besides, much of the automotive work won't apply. Which brings me to question how much might development of this engine cost?

Greg

 

[makoman1860]

I've been following along here. What is the story with Delta Hawk? Are they viable? I would think that multi-fuel (at least the ability to use kerosene) is beneficial.

With the twin prop arrangement I would expect noise due to the proximity of the prop tips to the fuselage. Has this been tested or is tip speed low enough to minimize this?

Fuel consumption piqued my interest. I saw mention of the BMW IIIa at 180g/HP-hr (240g/kWh), but the published tests put it at 270g/kWh? O-320, O-360 is something like 255g/kWh.

It seems knock limited large bore low RPM engines are pretty well sorted. Where is the increased efficiency going to come from? There is an interesting reference to the turbo versions burning much more fuel here, at the bottom of the page. Bristol was working with mechanical direct injection of gasoline during WWII, did it ever become common? Germany also used it in some airplanes in production, I think.

Niels, have you read anything about this company? http://www.achatespower.com It seems they are investing a lot in the Junkers type.

I agree that everything in the engine world was done by WWII when turbines took over. There have been advances since then, but the cost is staggering for the gains. Besides, much of the automotive work won't apply. Which brings me to question how much might development of this engine cost?

Greg

Hi Greg,
DeltaHawk is doing well, and not that far away from me. I think the cert process will finish up the summer on the 180 horse V4. Honestly that seems like a viable engine. They are fortunate to be in "engine country" here in Wisconsin and have many manufacturers local to pick brains and such. Time will tell how well it is executed.

Niels,
If you are suggesting that a new engine will come from china.....I would be beyond shocked if that happened.

 

[Niels Abildgaard]

Hello Greg

I have seen 185 gram per hph for BMWIIIa in a german book ISBN 3_7637-6107-1.
The firm of Hirth who makes two stroke ultraligth engines measured 160 gram gas/petrol on 313 ccm cylinders with mechanical injection ten years ago.
All german 1000hp engines or more after 1939 were mecanical directinjected.

Hello Makoman

The CAFE test some years ago were won by a Slovenian aircraft with an Austrian engine.
Solidly
Initiative is moving east.
Just as wired telephones were bypassed in Africa and parts of Asia by mobilephones,the same thing can happen with road vehicles and aircrafts.
80 to 100 horsepower (Rotax 912) is were the action and numbers are.

 

[makoman1860]

Hello Greg

I have seen 185 gram per hph for BMWIIIa in a german book ISBN 3_7637-6107-1.
The firm of Hirth who makes two stroke ultraligth engines measured 160 gram gas/petrol on 313 ccm cylinders with mechanical injection ten years ago.
All german 1000hp engines or more after 1939 were mecanical directinjected.

Hello Makoman

The CAFE test some years ago were won by a Slovenian aircraft with an Austrian engine.
Solidly
Initiative is moving east.
Just as wired telephones were bypassed in Africa and parts of Asia by mobilephones,the same thing can happen with road vehicles and aircrafts.
80 to 100 horsepower (Rotax 912) is were the action and numbers are.

Niels,
Honestly over here in the US, there is not as much interest in the CAFE "green" stuff anymore on a corporate level. The shift seems to have gone to total performance, not efficiency, even though they are intertwined. Just a different set of needs. Fuel is plentiful, noise is not an issue, and we have large distances to cover. The work here is going into racing it seems. That being said there are some really neat engines that have come out, and will come out in the near future, just not competitive to the little euro stuff. The rotax made a big splash here, but has been slowly drying up. The cost of ownership is higher than many thought. The Jabiru, Rotec, M-14P, and Lom type engines are very popular. Delta hawk will have their 180hp diesel out soon, with larger engines to follow. Not much on the smaller scale.

Where am I going with all of this. Just because a country is not doing something, does not mean they are not capable of it. With the light sport category we are seeing the popularity surge of "cub" type designs with little Cont O-200 base engines. It works, it sips auto fuel, is easy to work on, parts are everywhere, and taken care of they last forever. Whats not to love? Ever come to Oshkosh?

 

[Niels Abildgaard]

Hello Makoman

Have been to Sun and fun and heard a Harvard and later an Antonov 2 full blast.The AN 2 has double power and less noise.More tipspeed means serious more noise


All You want is an O 200 (with Cub) to parafrase Beatles.
Was on the web and found this

http://www.flycorvair.com/thrust.html.

80 horsepower at 2750 rpm on a 72 inch prop is 265 meter per second tip speed and You are not allowed to fly in many parts of Europe and a lot of other crowded places.
American small arms and noise tolerance is not easy to export.
The O 200/Cub combination is not the future and I have reconsidered the functional model I want to builld based on some moped conrod parts I have.
60 mm stroke times two and bore 40 mm ie of the shelf chromed piston rings.
Some pictures.
If some one north of the Alps are tempted to join the moneyless fun and share the Glory (In heaven I asume) let me know.

 

[makoman1860]

So what you are telling me in short, is that you are trying to find an engineering solution to a social problem?
The way things look, Europe might just restrict themselves out of ever needing a new aviation engine. I am glad I live in a place where people still run outside to catch a glimpse of that airplane that just buzzed their house instead of phoning in a noise complaint.

 

[mu38&Bg#]

Your comment about Hirth, is that with the Orbital system? 160g/kWh in 300cc two stroke? The best I read about Hirth/Orbital is 330g/kWh. I think you have to be realistic with BSFC.

This adaptation of an auto diesel looks intriguing. http://flyeco.net/smart_diesel.html

 

[Niels Abildgaard]

Your comment about Hirth, is that with the Orbital system? 160g/kWh in 300cc two stroke? The best I read about Hirth/Orbital is 330g/kWh. I think you have to be realistic with BSFC.

This adaptation of an auto diesel looks intriguing. http://flyeco.net/smart_diesel.html

Hello Greg

It was 160 gram/bhph.
Hirth did not tell me what system.
Maybe a full mechanical high pressure like gutbrod 1952
NSU Lux 200ccm motorbike returned 200 gram /bhph in the early fifties.
Fuel octane and compression ratioes are higher today so below 200 are realistic.
Austrian engine developers AVL claimed 245 gram/kWh on a 100 ccm two stroke semidirect injection.
Orbital must have done better than 330 gram/kWh.

Combination of the three cylinder fourstroke diesel- toothed belt reduction(?)- and high inertia propeller is not flying me over hostile terrain.

 

[Niels Abildgaard]

The endless journey ( I had the vision 1988) takes a new turn.
In DDR a lot of motors was made and unused spares are cheap and awailable

http://www.crazybikes.net/el308_1.html

so here comes next scheme for trying.
Stroke 68.5 mm bore aprox 48 mm and based on crankcase and cranks as found in Germany

Angle Grinders are cruel.

 

[Tin Falcon]

The other day a friend e-mailed me about the Boeing Phantom Eye project .

The interesting thing here is the power plants are ford engines. Similar to used in the ford ranger and or fusion.
the main tweak is tuning them to run on Hydrogen. Stored in liquid form. the original reports mention turbo chargers but with a 65K foot flight level I think they are carrying Liquid O2 as well.

I expect All the nuts and bolts are safety wired as well.

My son had a ford ranger that had dual spark plugs IIRC this is something typical in AC engines.

Interesting though in the day of high speed turbo/jet engines that Boeing powers there latest UAV with something akin to what is found in the family car or truck.

Good to see ford building aircraft engines again.
Tin

 

[Niels Abildgaard]

Hello Tin Falcon

The Pietenpol Aircamber was one of the first homebuilts that multiplied.
Engine was a Ford A direct drive.
Can we get some information on this high altitude thing?
If it is a fourcylinder geared one,what kind of coupling gearing?
In the mean time the horrible angle grinder criminal has struck again.

 

[Tin Falcon]

Can we get some information on this high altitude thing?

Just Google Boeing Phantom eye. there are various videos out there. This project has been in development for a couple years. They are now field testing the prototype.
Tin

 

[Niels Abildgaard]

Somehow it feels wrong to use discarded engines for proving my wild ideas.
It cannot be said that I have not tried to make suitable crankshafts but up til now in wain.They either wobled or looked wrong.
My getting wiser engine shall (for the time being) look something like second picture and third picture shows the critical connection of hardened conpin to crankdisc.
The conpin is casehardened ,that means the outher mm is very hard and core not so but tough.
It is easy to turn end to shape shown using a homegrown tangental carbide tool.
It is then put on disc and pulled tigth by the M8 12.9 Unbrako screw using 25 Nm torgue giving ca 2 tons force.Screw can stand 2.5 tons ultimately.
I then removed the screw and pressed further with 8 tons.
The V shape valley in disc is now about .8 mm wide and pin is unchanged.
Very cheap fast and easy.
It migth even work.

 

[roleic]

Dear Neals,
I hope you are well. Thanks for your many posts on 2-stroke diesel aircraft engines. I agree that they are underrated and deserve a closer look. However the double piston version with 2 crank shafts seems very heavy (and costly) especially for aircraft engines. The Jumo 205 from the 1930ies came from the airship era and was not suitable for high performance aircraft. But the concept of a light, 2-stroke, Schnuerle ported, single crankshaft, exhaust turbo-charged, inter-cooled, diesel engine with a modern, highest pressure injection system (common rail, piezo valve control) would make very much sense especially in a V or radial layout. The big advantage with that concept is that you don't need to feed the air intake through the crank case as in traditional 2-stroke engines but in separate lines allowing for a normal oil lubrication of the crankcase creating oil free exhaust gases like in 4-stroke engines. If the engine is started with compressed air out of a light kevlar composite tank, spinning up the engine AND the turbo charger, and not with an electric starter as in cars, which does not spin up the turbo, you could reduce the mechanical compression ratio to take more advantage of the turbo charger at all altitudes. It could leave all other piston engines behind in terms of power per weight ratio (second only to gas turbines), fuel efficiency (second to none), low noise without reduction gear due to high torque at low engine revs. Such an engine could be so superior that it could become an interrupter for traditional aircraft engines which are mainly built by corporations being a part of the US military industrial complex with close ties to the US government (including FAA making certification extra difficult) and clandestine services (scaring foreign authorities from certifying and investors from investing). That leaves only the small experimental, home- and kit-built market. That is where Rotax started AFAIK... The main technical challenge is the injection system. The other main challenge is to gain enough money in the kit-built market to afford to jump over all hurdles the authorities put in your way to certification for the bigger general aviation market.

 

[Niels Abildgaard]

Hello Rolleic

Glad You have read it.
My aircraft engine thinking is Otto (spark ignition) engines only.
Diesels are useable for ships and locomotives maybe , but not for flying.

Some examples here

http://archive.is/G9Hpk

Young people in Copenhagen claimed 210 gram petrol for one kWh and a very good WV diesel is 195 that is 15 gram difference for say 60 kW makes 900 gram per hour in favour of a diesel engine that is probably 6-8 kg more heavy.
No deal.

 

[Mechanicboy]

Diesels are useable for ships and locomotives maybe , but not for flying.
.

Reading this further..

https://en.m.wikipedia.org/wiki/Aircraft_diesel_engine

 

[WOB]

The picture shows my fall back option if the Junkers thing is no good.
The german Argus 10C engine was 15 kg per litre and ran at 8.5 bar mean effective pressure.My Rotax 912 Erzatz will be 2 (92 mm bore and 150 stroke) litre and run at 7.5 bar and a mean piston speed of 12 m per second.Engine mass can thus be less than 30 kg plus turbo and cooler.Not much.
Four cylinder fourstrokes has a reaction torque variation dominated by the second order composant and is basicly the difference You feel between a six and a fourcylinder engine.It is zero in a V2-90 degree two stroke.

I didn't see this question asked, so pardon me if it has. Why a V configuration? It shakes. A 180 degree flat twin does not shake. See http://sense.net//~blaine/twin/twin.html

WOB