Bring On The DORA

[RAM]

 

Originally posted by funked:


 Nope, it had MW 50 for sure.  Wells did some really nice test charts and they showed the same performance as RLM MW 50 stats.

Well, the pages of Wb I have seen so far talk about a D9 with 426mph top speed.

And that speed is the one of a 190D9 with no MW50...

[funked]

Those pages are wrong RAM, unless the flight model has been changed in the last 6 weeks.

[juzz]

Hey! I just d/l WarBirds 2.76(35Mb minimum with only low-res F6F cockpit art!!!   ), I can check that!  

Yep - it certainly does do more than 357mph at S/L. I'd say, about 380mph.  

[This message has been edited by juzz (edited 10-24-2000).]

[Minotaur]

I have some questions about MW50, Water injection and WEP.

To my understanding the MW50 system included a small tank tank that contained a mixture of methanol alcohol and water.  To gain added engine performance this mixture was injected directly into the cylinders.  The engine then had a noticeable Hp increase.  This Hp increase was because the engine, in effect, operated some what like a steam engine.

Some US planes had a system that was similar, but only used water and a tank that was much larger.  I had thought that this system was used by the big radial engines and that this water system was in use when ever the engine was running.  I thought that this system operated by using a fine mist of water sprayed into the intake manifold.  It basically had the same function as MW50.  By giving the engine a steam engine effect.

Concerning AH, the issue of WEP comes to my mind.  For AH, WEP is modeled as increased engine output for a period of 5 minutes for most planes and 10 minutes for German planes.  The AH WEP can be used until a high engine temperature condition exists, then can not be used until the engine cools.

In this thread it is stated that the AH 109G-10 uses MW50.  Is MW50 automatically engaged when the player selects WEP?  If so then it seems that there should be only one 10 minute period of "maximum" WEP or however long the MW50 supply lasted.  Then the following use of WEP would be at a reduced Hp as compared to the MW50 WEP.

More questions...

Does the water injection for US planes only have a 5 minute duration?  Is it only applied when WEP is used or is it used all the time?.  If it does should not the same rules apply as those for MW50 WEP.  One use, and then reduced Hp for further WEP's?

I had thought that WEP was more like a bypass of the normal throttle setting.  This being a bypass function to the normal throttle stop.  So WEP simply allowed a higher manifold pressure and engine Hp output at the expense of temporarily allowing the engine to exceed the capacity of its cooling system.  Basically trading higher engine Hp at the expense of higher engine temperature.

I could research this on my own and not seem such the dummy, but this seems much easier and quicker.  I know that there is a vast pool of ready knowledge lurking.

Thanks in advance!  

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Mino
The Wrecking Crew

"Anyway, more golf..."
Humble

[RAM]

AFAIK you are wrong. MW50 ijected methanol-water mixture into the cylinders not to make them work like a steam  machine, but to cool them down and allow for a higher power output for a longer time without overheating the engine.

I think it has nothing to do with the water injection system...but I can be wrong  

[funked]

MW 50 and the US methanol-water injection systems are pretty much the same thing.  They worked as anti-detonants.  You could run higher boost pressures without running into detonation.  There were other benefits as well but this was the main one.


[This message has been edited by funked (edited 10-24-2000).]

[Jigster]

 

Originally posted by funked:
MW 50 and the US methanol-water injection systems are pretty much the same thing.  They worked as anti-detonants.  You could run higher boost pressures without running into detonation.  There were other benefits as well but this was the main one.


[This message has been edited by funked (edited 10-24-2000).]

The injection also increases the compression ratio, increases the air density, and provides higher chamber pressure after detenation via the vaporizing water. (i.e. like a steam engine)

I have a 1942 John Deere H that had the optional water carb. affixed to it. It worked somewhat like it's aircraft counter parts, with the exception that it only worked on hot days or days with low humidity. It gave about a 3 HP boost on either kerosene or gasoline, and a little less on cheap distillites. While that don't sould like much, it only has an 8 HP engine. But, that 3 HP created another 250 foot/pounds of torque at the drawbar.

And when you get into 1,500 to 2,000 HP engines, the benefits are, well, much greater  

- Jig

[juzz]

The RAF didn't use additives - instead, they used 150 Octane fuel to achieve much the same power gains. Eg: DB 605A from 1475HP->1800HP with MW 50, Merlin 66 from about 1700HP->2100HP with 150 Octane fuel.

[Minotaur]

My Father, when I was a "wee lad", was an automobile mechanic.  One of his customers was developing a water mist injection system.  This system was designed to be  attached to the air filter.  My Father did the assembly while the customer did the design.  

The engine was naturally aspirated, used a carburetor and the ignition timing system was not modified.  The test car was a VW Beetle, which has an air cooled engine and is generally a pretty under powered vehicle.  

Although not used all the time, the system was turned on for climbing hills and passing.  With the water system on, the engine exhibited a very noticeable Hp increase.

As I recall, a topic of discussion at the time was the caution to be used in adjusting the water injection rate.  The fear was that too much water would place too much stress on engine components and lead to rapid failure.

I don't believe that they mixed any Methyl Alcohol with the water.  I am not sure why.  

Methanol to my knowledge is a poor fuel, considering energy released as compared to gasoline.  The primary advantage to Methanol is that it burns with very cleanly and that it burns relatively at a low temperature.  Additionally Methanol burns at a much slower rate than gasoline.  When Methanol is mixed with gasoline it, in effect, acts like a combustion retardant.  

Would this effect to retard the overall fuel combustion rate, preventing detonation (pinging), for the gasoline / methanol combination?

Thanks for the replies!    


------------------
Mino
The Wrecking Crew

"Anyway, more golf..."
Humble

[This message has been edited by Minotaur (edited 10-25-2000).]

[fd ski]

 

Originally posted by juzz:
The RAF didn't use additives - instead, they used 150 Octane fuel to achieve much the same power gains. Eg: DB 605A from 1475HP->1800HP with MW 50, Merlin 66 from about 1700HP->2100HP with 150 Octane fuel.

yeah, and odds of us getting that are.....

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Bartlomiej Rajewski
aka. Wing Commander fd-ski
Northolt Wing
1st Polish Fighter Wing
303 (Polish) Squadron "Kosciuszko" RAF
308 (Polish) Squadron "City of Cracow" RAF
315 (Polish) Squadron "City of Deblin" RAF

Turning 109s and 190s into scrap metal since 1998

Northolt Wing Headquarters

[flakbait]

Our 109 G6 should have GM-1, but I don't know the specs of a G6 to know for sure. Nearly every Bf-109 G6 aircraft were factory fitted with GM-1 boost [Goring's Mischung]. Every G model had the provision for installation of it. Squadron/Signal book "Bf-109 in action part 2" has this line in it refering to the GM-1 system:

 

"...not only allowing the G to operate above the rated altitude for the DB-605, but to literally leave a persuing Spitfire V standing still."

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Flakbait
Delta 6's Flight School
"My art is the wings of an aircraft through the skies, my music the deep hum of a prop as it slices the air, my thrill the thunder of guns tearing asunder an enemy plane."
Flakbait
19 September 2000

[This message has been edited by flakbait (edited 10-25-2000).]

[fd ski]

 

Originally posted by flakbait:
Nearly every Bf-109 G6 aircraft were factory fitted with GM-1 boost [Goring's Mischung]. Every G model had the provision for installation of it.

You have got to be on crack...

Please find some more good sources to back this up.... last time this same kind of bs was being sprewed about MW50.


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Bartlomiej Rajewski
aka. Wing Commander fd-ski
Northolt Wing
1st Polish Fighter Wing
303 (Polish) Squadron "Kosciuszko" RAF
308 (Polish) Squadron "City of Cracow" RAF
315 (Polish) Squadron "City of Deblin" RAF

Turning 109s and 190s into scrap metal since 1998

Northolt Wing Headquarters

[juzz]

Considering that the Me 109F-4 could leave the Spit V behind at 30k+, I think the "improved" Gustav bloody well ought to as well, GM-1 or not...

[Wanker]

Creamo said:  

The Luftwhiners can’t possibly whine anymore.

Wanna bet?  

[flakbait]

Fd ski, every Bf-109 G model had the provision for installing GM-1. Note the bold; provision. This doesn't mean every G had it installed, but it was available for installation. I know the G6 had GM-1 installed from the start, along with the paddle prop from the F model's "Z" option (designated U-2). Pressurized variants (G-1, G-3, G-5) either had it standard, or the option of installing it. The latter being more common than the former.

I got this information from Squadron Signal Publications, Aircraft #57 "Messerschmitt Bf 109 in action, part 2". And from a few web sites which give somewhat conflicting info. They either say "I guaran-damn-tee you it was there" or "it was only an option, and was nearly never used". I simply said "screw it, split the difference". Oddly enough, the Luftwaffe Resource Group states all G6 models used the DB-605 AM engine.

If you've got a great source for 109 info, tell me. If I'm wrong then at least I'll be able to get better info in the future.



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Flakbait
Delta 6's Flight School
"My art is the wings of an aircraft through the skies, my music the deep hum of a prop as it slices the air, my thrill the thunder of guns tearing asunder an enemy plane."
Flakbait
19 September 2000