Mistral proceeds toward certification

Rotary10-RV · #1 04-04-2008, 12:11 PM

Mistral Engines posted to the ACRE site recently that they are approaching certification on their G300 3-rotor (300 HP) and are seeing very good Hp and BSFC numbers. They have changed the desination of their G190 engine to G200 because they are now producing a consistant 200+ HP. They posted the HP curves and BSFC curves for the engine. Their redundant EMS is configured to take advantage of the rotaries ability to run LOP safely and they have posted the numbers in both the ROP (max power) and LOP (best economy) configurations. Both engines use the same PSRU a purpose built 2.8:1 reduction planetary. All the G200 numbers have been logged in-flight on their Piper Arrow with the rotary installed. Looks like there will be at least 1 more certified possibility in the near future. I've linked the performance graphs
Bill Jepson

kcameron · #2 04-04-2008, 01:34 PM

Thanks, Bill. I've been watching Mistral for years hoping they'd finally show fuel burn numbers. I can't find it on their site though: http://www.mistral-engines.com/index_files/Page423.htm

Maybe that site is outdated? Also, what is "the ACRE site"?

kcameron · #3 04-04-2008, 01:38 PM

Also, It looks like you forgot to insert the links.

JakeC · #4 04-04-2008, 02:14 PM

The ACRE is Paul Lamar's email list that deals with Rotary engines in aircraft. Here is the link to the subscription page. It's called the Aircraft Rotary Engine Newsletter on his home page but it comes through the email labled ACRE. Not sure why. He also has some interesting articles listed on his main webpage, here.

Rotary10-RV · #5 04-04-2008, 02:37 PM

Quote:

Originally Posted by kcameron

Thanks, Bill. I've been watching Mistral for years hoping they'd finally show fuel burn numbers. I can't find it on their site though: http://www.mistral-engines.com/index_files/Page423.htm

Maybe that site is outdated? Also, what is "the ACRE site"?

No, Kevin the site is not outdated, but Mistral has been holding the numbers until finishing on the G300. Francois the CEO has a good relationship with ACRE, (Aircraft Rotary Engine) newsletter and did something of a "pre release" of the happenings.
I have the excell spreadsheet of the G200 which looks great. I'm trying to figure how to put it on here. Max power rich of peak (ROP) on the 2 rotor is 200 HP at a BSFC of .57. The real suprise are the LOP cruise numbers. 75% power running LOP which the rotary is totally SAFE with BTW, are showing 168HP at a BSFC of .44! that is in there with the best them when running gasoline. Mistral is incorporating the LOP operation into their EMS which will really help the cruise and range numbers. Francois said that the G300 3 rotor is making the design 300 HP very easily they are control limiting the engine to 6200 RPM. That is on Mogas too, 95 RON (90 US) regular or mid-grade unleaded gas. The Mistral guys are out front about everything saying they wanted to get the NA engines done first because they are the easist. The 230-240 turbo 2 rotor will follow. They are working on turbo sizing and being sure the turbine wheel is tough enough to endure the high temp exhaust of the rotary. He commented that the turbo 2 rotor could easily make 300+ but they felt that they needed to limit it so bad gas wouldn't cause detonation problems. the same type of problems experienced by regular aircraft turbo engines.
Bill Jepson

rv6ejguy · #6 04-04-2008, 02:49 PM

Excellent. I'm glad Mistral has stayed with it. It has been a long journey. Those are really good numbers and tend to support what Tracy Crook has been saying for a long time- LOP, Wankels are pretty good.

The next step will be getting them out there are seeing how they really do in use.

I like how they have had a test airframe for some time and can validate in the test cell as well as in actual flight. They have seemed to do it right on not a massive budget and haven't posted a lot of unbelievable information- rare indeed.

Rotary10-RV · #7 04-04-2008, 04:44 PM

Quote:

Originally Posted by rv6ejguy

Excellent. I'm glad Mistral has stayed with it. It has been a long journey. Those are really good numbers and tend to support what Tracy Crook has been saying for a long time- LOP, Wankels are pretty good.

The next step will be getting them out there are seeing how they really do in use.

I like how they have had a test airframe for some time and can validate in the test cell as well as in actual flight. They have seemed to do it right on not a massive budget and haven't posted a lot of unbelievable information- rare indeed.

Quite true Ross!
Paul Lamar visited Mistrals florida location where they are working with Embry Riddle on the Piper Arrow. He was given a ride in the plane and was very impressed. His site has a link to the video of the flight. ACRE is www.rotaryeng.net I believe. Paul often run down some odd tangents but there are many people colaborating and there's frequently some good information there.
Bill Jepson

Michael White · #8 04-04-2008, 05:33 PM

Here is the Power and Fuel Consumption chart:

http://img382.imageshack.us/img382/4...umptionen7.jpg

And here is the Power and Torque chart:

http://img241.imageshack.us/img241/9...dtorquefo7.jpg

SHIPCHIEF · #9 04-05-2008, 02:21 AM

I would suggest that most of gmcjetpilot's comments are true...up until electronic engine management and continuous high load operation are considered.
His friend with an RX-8 will never benefit from the rotary engine's true advantage, which is continuous high engine load economy @ LOP.
The rotor path geometry is inferior to a traditional piston, true. However the wide open exhaust and intake ports don't have the throttle losses incurred by Piston Engine's old poppet valves which never get out of the gas path. I say the results could be a wash with computerized fuel injection and LOP.
Also; the fuel is thrown centrifugally toward the spark plugs because the intake charge is carried around from the intake side to the combustion side. The resultant stratified charge is easily lit by the plugs even though it would be too lean to light in a piston engine.
As for noise, some rotary powered aircraft are quieter that thier piston powered siblings, mufflers have been a problem in the past, but now better mufflers have been developed that can withstand the high energy exhaust pulses.

The Rotary Engine community is growing, and the results look pretty good.

SvingenB · #10 04-05-2008, 04:09 AM

Comparing the CO2 emmisions (EU standard for cars) of the Mazda RX8 with the state of the art Wankel, the RENESIS engine, to the similarly powered BMW 325 (stright 6), they are 267 and 225 g/km respectively. This means that the RENESIS uses approximately 15% more fuel on average. For the sake of completeness, the much stronger BMW 3.0L diesel with 500Nm of torque only has 174 g/km of CO2 (35% less fuel compared with the RENESIS).

However, the EU standards for car CO2 emmisions is made for average car operation incl city driving, highway and so on, and not for peak power operation. At high load the Wankel can operate with a much leaner mix than a gasoline piston engine, so no one should be surpriced if a state of the art Wankel would actually be more efficient than a similarly powered gasoline piston engine.