Rotary diesel?

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Reg LeBlanc

Member
Joined
Nov 13, 2006
Messages
15
Location
Haley Station Ontario Canada
Hi All: I'm not sure if this is the right place to ask but,does anyone have any information on a rotary engine that will run on diesel fuel. I have been told that there was something at Oshkosh a while back. I haven't been able to find any info on who it was or what the details of the engine were. Regards...........Reg
 

Kristoffon

Well-Known Member
Joined
Sep 4, 2009
Messages
348
Location
Brazil
From memory I believe the high compression ratio required for diesel doesn't suit rotaries very well and I also recall seing a photo from a diesel which used a first rotor to compress air for a second rotor to compress further and do the actual combustion.
 

Monty

Well-Known Member
Joined
Jul 15, 2010
Messages
1,294
Location
Fayetteville, AR / USA
You mean like this

I wouldn't get my hopes up.

Diesel is harder to make big power in an intermittent combustion engine. It burns too slowly. The new high pressure common rail systems may solve this. You could also probably use an electrically boosted turbo for starting...

It's still going to be a real challenge. The rotary has one serious achillies heel and it's not what many people think. I personally love rotaries, but the continuous power output is limited by how much heat you can move away from the combustion area around the spark plugs. Unlike a piston engine the combustion chamber does not get to rest between combustion events. The common wisdom for the MAZDA is 100 hp per rotor continuous without any problems. Although the engine can make far more than that, you will get cracking around the spark plugs if you try to do it continuously. Trying to air cool it is a big mistake in my opinion for this reason. High power density should mean liquid cooling unless the laws of heat transfer are different at Pratt.
 
Last edited:

Monty

Well-Known Member
Joined
Jul 15, 2010
Messages
1,294
Location
Fayetteville, AR / USA
Why would you be using spark plugs on a diesel?
That is actually a very good point. Most of the rotary diesels that have been tried are spark assisted. The compression is too low and the combustion chamber too odd shaped to get complete combustion. This problem may possibly be solved by using the high pressure common rail system. However, it still does not eliminate the problem of cooling the combustion chamber on the rotor housing, and you still need a hole for the injector/s.
 

Dan Thomas

Well-Known Member
Joined
Sep 17, 2008
Messages
5,084
Didn't Zoche (sp?) have a radial diesel?
Yes. But radials have pistons just like any other gasoline or diesel engine. You might be thinking of the radial rotary of WWII, the Gnome and its type, where the whole engine spun while the crank was attached to the firewall. The Wankel/Mazda rotary engine has no pistons or cylinders as we know them.

Dan
 

Starman

Well-Known Member
Joined
May 16, 2009
Messages
2,011
Location
High in the Andes Mountains
Even if a rotary can be made strong enough to handle the pressure it probably wouldn't work as a diesel anyway because there's so much quench area that it probably wouldn't get hot enough to ignite.
 

JCP

New Member
Joined
Oct 25, 2010
Messages
2
Location
Long Island, Ny, USA
The German company "WankelSuperTEC" appeared to have an approach to a Wankel-Diesel that looked very promising.

Direct Injection with a Spark plug to get it started.

Once Turbo spooled up under load, would run as a Diesel.

Turbo boost (2:1 to 3:1) plus Wankel compression (8:1 to 9:1)
got you into normal Diesel compression ratios.

No Intercooler, hot compressed air out from Turbo further compressed and heated by Wankel compression cycle to diesel ignition temperatures.

Hence 2 stage compression, and 2 stage expansion.

At light load (i.e., low boost) I've heard that it needed spark to run smoothly. (or a glow plug)

Project either ran out of money or went black and may now be powering drones.

JCP
 

JCP

New Member
Joined
Oct 25, 2010
Messages
2
Location
Long Island, Ny, USA
And sometimes very good valid patents have to expire before an idea moves forward.

i.e. Rosen Motors had an energy efficient electric car 10 years ago running a fantastic small gas turbine with flywheel energy storage, which suffered from "Death by Detroit". (the Big Three were not about to pay the Rosen Brothers a dime for their patents.....)

This year Porsche ran a flywheel energy storage car at Le Mons.....
Conspiracy ? No, just business, just a matter of money flow...

Anti-Wear Coatings, Heat Rejection Coatings, and Seals have all improved. Perhaps it is time to revisit a Wankel-Diesel !

JCP
 

charles

Well-Known Member
Joined
May 3, 2010
Messages
120
Location
northcarolina usa
IT WILL RUN ON DIESEL, kerosene,the more rpms it gets the more compression it will have.add glow plug ,add air heat,spin over rotor very quick. I ALSO GOT THAT SPAM JUNK MAIL TODAY WANTING TO SET UP A BANK ACCOUNT FOR 4 &1/2 MILLION DOLLARS.I DELETED ALL OF IT. VIRUS??????
 

Jman

Site Developer
Joined
Oct 22, 2002
Messages
1,881
Location
Pacific NW, USA!
I ALSO GOT THAT SPAM JUNK MAIL TODAY WANTING TO SET UP A BANK ACCOUNT FOR 4 &1/2 MILLION DOLLARS.I DELETED ALL OF IT. VIRUS??????
I took some steps that should keep that from happening again. Let me know if you get any others that are related to HBA. Thanks Charles....
 

Turner

Well-Known Member
Joined
Dec 19, 2010
Messages
78
Location
Stockholm / Sweden
As was already mentioned, Wankel Supertec and Wankel AG (both in Germany) are running a joint venture in a new line of diesel rotaries. It looks promising with plans for a range of engines of 1 up to 4 rotors, with 500 cc per rotor. They say they can get 65 hp per rotor which sounds reasonable.

I'm following their development with great interest.
 

Streffpilot

Well-Known Member
Joined
Jul 12, 2011
Messages
318
Location
Mukwonago, WI
What about the Renesis with its High Tech intake and fuel delivery system........how would that work running on desiel....maybe not a compression run desiel, but running on that fuel (or JET A)
 

dino

Well-Known Member
HBA Supporter
Joined
Sep 18, 2007
Messages
635
Location
florida
Zoche diesel radials are alive but not running. They exhibited at Aero 2012 last week. They have pursued design, patenting and prototyping but have stopped there most likely intentionally as it a more viable to develope using EU grants than it is to manufacture.


Dino
 
2
Group Builder
Top