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Levon1981
10-22-2005, 01:22 PM
In the museum of the game it's written that FW-190A-4 (unlike previous modifications) had MW-50. But when I fly the plane the MW-50 isn't working, why?, is it just a bug from caused bu my PC, a bug of the entire game? or what? I don't know what to think, if you can give me any info concearning this, I'd be gatefull.

GH_Klingstroem
10-22-2005, 01:59 PM
im with you on this one! the Fw190A4 did indeed have this

From the book "Focke wulf in action"

"To increase its performance the A4 series was equipped with a methanol-water 50 (MW50)power boost system in order provide extra power below 16 000 feet"

Why the a4 in this game does not have it I dont know... Sure she is fast as it is but it wouldnt hurt to have it in 1942 servers... http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

I also read somewhere in that book that the A4 engine ran at 2700rpm and not 2400rpm as we now have in the game... Cant find the statement in the book now tho...

3.JG51_BigBear
10-22-2005, 02:05 PM
We have the A4 version that was common on the Eastern Front. Focke Wulfs were used more for ground attack in the East and given the quality of opposition in the early war period the lower powered A4 was good enough.

JtD
10-22-2005, 02:07 PM
Instead of MW 50 the Germans used higher grade C3 fuel and to my knowledge MW50 was never used on the A-4.

GH_Klingstroem
10-22-2005, 02:23 PM
JtD check my quote from the book above! It seems like the A4 had MW50 as standard according to the book...

JtD
10-22-2005, 02:49 PM
Yes, many books say so.

There are also a lot of books that say the Bf 109 E was armed with 3x20mm cannons...

But afaik the MW50 installation was tested and not adpoted. MW 50 was just used to allow engines to get the similar performance from the worse B4 fuel they got with C3 fuel.

109's used B4 fuel and got the MW 50 system, however, Fockes with BMW always used the C3 fuel instead of B4+MW50.

C3 is better than B4+MW50.

Kwiatos
10-22-2005, 03:22 PM
Probably first serial Fw 190 with MW50 was A-8. Previous version have only tank for MW50 but didnt used it.

CUJO_1970
10-22-2005, 03:38 PM
Originally posted by GH_Klingstroem:
JtD check my quote from the book above! It seems like the A4 had MW50 as standard according to the book...


Sorry, but MW50 was never serialized for the FW190A-4.

Probably it was tested, but it was never put into production. At this stage, BMW was injecting C3 fuel directly into the eye of the supercharger - it had the benenfit of requiring no extra tank,plumbing, or fluid to be carried.

So C3 injection saved weight and space.

There is evidence that Methanol/Ethanol could be(and was)used some on the later A-series fighters.

Bremspropeller
10-22-2005, 03:51 PM
MW-50 was never operationally used with any Fw 190A flown on among a front-line unit (though A-8s and A-9s had an additional tank to be filled with MW-50 - which was generally filled with "normal" fuel or even removed).


The only operational 190s that had a MW-50 boost were the Doras (from jan.'45 on).

faustnik
10-22-2005, 05:34 PM
There is evidence that GM-1 was used in operations.

The way Crumpp explained it was that C3 injection (EN cooling) produced better results the MW50. All BMW801s ran on C3 grade fuel so, there was no benefit from using an MW50 based cooling system. The late Doras took advantage of MW50 because it the Jumo could run B4 fuel and therfore get increases in performance from MW50.

Ratsack
10-22-2005, 05:52 PM
Originally posted by faustnik:
There is evidence that GM-1 was used in operations.

The way Crumpp explained it was that C3 injection (EN cooling) produced better results the MW50. All BMW801s ran on C3 grade fuel so, there was no benefit from using an MW50 based cooling system. The late Doras took advantage of MW50 because it the Jumo could run B4 fuel and therfore get increases in performance from MW50.

Yes, I was going to say, 'Call Crump if you want an explanation.'

I recall reading that some A4 Jabos on the Channel Front had the MW50 for the low altitude boost, but I've never seen it confirmed.

Ratsack

ZG77_Lignite
10-22-2005, 07:27 PM
Faust, I'm not an expert, but I think thats not quite right; Brems has it I think. It doesn't (necessarily) matter what grade of fuel is used. The injection, be it MW50 or C3 mixture, is used to cool the supercharger blower (C3 does just as well as MW50 for this) and lower fuel detonation point allowing for higher manifold pressures (more horsepower). MW50 will more quickly lower detonation points, which is why it is more common when B4 fuel is used, such as late in the war. C3 (high octane) fuel already has a fairly low detonation point, thus it doesn't require anti-detonants (much like American 150 octane).

B4 fuel is a lower octane fuel (higher potential energy), and can be used by any engine, but its easier combustion requires lower compression ratios (mechanical adjustments, less power).

Like Bremspropeller said, no -A's with MW50 were ever used. They were capable of it from the A4 on, but lack of the correct apparatus, combined with the fact that it was not a significant improvement over C3 injection kept it out of use. The FW190A-4 in game does not have C3 injection, and the result is its lower manifold pressure (and horsepower) rating.

Buzzsaw-
10-22-2005, 08:06 PM
Salute

As Cujo/FW190 Fan said, there was no use of MW-50 by any 190 model except the D series, and only after December of 1945. Earlier D models, as is shown in the game, used C3 injection.

MW-50 could work with C3 fuel, but the issue is not whether it would work, but whether or not the engine could sustain the boost level without damage occurring.

Both direct C3 fuel injection into the supercharger venturis, and Methanol/Water 50/50 injection, (MW-50) aim to do the same thing, ie. to reduce heat in the combustion chamber and therefore detonation. How they do that is a little different process.

First of all, combustion in a reciprocating engine is a function of a fuel/air mix being created by the velocity with which the two elements are drawn into the combustion chamber. The mixing of the elements, ie. the 'atomization', of the fuel and oxygen molecules, is the process whereby the molecules of fuel and air are broken down into gaseous form and mixed. This gaseous mix is very suseptible to being ignited by a spark, and provides excellent combustion.

What works against good combustion, is the extreme heat generated by the combustion process. The cylinder combustion chamber can become so hot, that the fuel/air mix tends to ignite spontaneously, BEFORE the spark plug fires. This is called DETONATION. Detonation is counterproductive, since it means the explosion which results, will happen BEFORE the piston reaches top dead center. Ie. the piston is coming up to top dead center, or the highest point of its stroke, and the force of the exploding fuel is pushing back against it, working against the overall smooth revolution, (reciprocation) of the engine. Detonation can also spontaneously happen as a result of the fuel/air mix being compressed to a very high number of atmospheres. This is why the level of supercharger boost cannot be set too high. Counters to this are fuel types which have very high 'Anti-knock' ratings, which means they are resistant to spontaneously detonating as a result of excees heat and compression.

The MW-50 process adds an extra process into the equation, ie. water and methanol. In addition to the fuel and air, we have water/methanol injected into the combustion chamber. When it arrives there in the midst of enormous heat, the water and methanol is also atomized, and the water molecule is broken down into its components, ie. H2O broken down into Hydrogen and Oxygen. The Oxygen released from the water gives a better combustion process in the cylinder head, (oxygen is needed for combustion) and the heat dissapated by the atomization of the H2O reduces overall cylinder head temperature, and thus reduces detonation. In addition, the hydrogen provides combustible fuel, as well as the methanol.

The direct C3 injection uses a different set of processes. When an engine is operating at very high RPM's, and injesting very large forced, (from the supercharger) volumns of air/fuel mixture into the combustion chamber, the atomization of the fuel/air mix becomes somewhat less efficient, and droplets of fuel are persistent and don't fully break down into gaseous form. The result is a less than perfect gaseous mix in the combustion chamber, and the gas which is there tends to be on the lean side for combustion purposes. Lean mixtures tend to produce more heat when they combust, and heat increases the chances of detonation. By injecting additional fuel into the supercharger venturi, the designers accomplish two things. First, the fuel directly injected into the supercharger is more thoroughly atomized, and addition, it adds overall to the richness of the mixture in the combustion chamber, thus reduces heat generation during combustion, and the likelyhood of detonation.

Grey_Mouser67
10-22-2005, 08:19 PM
Problem with books are, once one error gets published, it tends to get copied over and over and over.

I can't say what the A-4 had in real life, but I can find scores of errors printed in books...the most notable one, due to my fancy for the aircraft, is the speed of the P-38L listed as 414...a common error that has been copied to several books....books just use other books as resources and references.

Oleg must make choices about what data he uses because there is much contradictory. If for some reason, he chooses to boost the A-4 I hope he inserts and A-2 and/or A-3 for replacement. The A-4, as modelled, is basically an A-3 afaik.

faustnik
10-22-2005, 08:56 PM
Originally posted by ZG77_Lignite:
Faust, I'm not an expert, but I think thats not quite right; Brems has it I think. It doesn't (necessarily) matter what grade of fuel is used.

Yes, I should have been more clear. Mw50 could certainly be used with C3 or B4 systems. The use of C3 in place of Mw50 is just as effective, simpler, and better for the engine. So, if you have C3, there is no need for Mw50 with the BMW801s if you have the EN C3 injection system insatlled. BMW801s didn't run on B4, they were sensitive engines that ran on very specific fuel mixtures.

The Jumo213 could run on C3 or B4. When run with B4, the Mw50 cooling (anti-detonation) would be a benefit.

I like Buzzsaw's explaination of the process. http://forums.ubi.com/images/smilies/25.gif

faustnik
10-22-2005, 09:11 PM
Originally posted by ZG77_Lignite:
The FW190A-4 in game does not have C3 injection, and the result is its lower manifold pressure (and horsepower) rating.

All BMW801Ds were rated at 1.42ata@2700rpm until Fall '43 when jabos with EN cooling were rated to 1.58ata under 1,000 meters. In '44 all EN injected Fw190 BMW801D fighters were rated to 1.58ata at all altitudes.

Some, the percentages are still unknown, Fw190A3s with BMW801Ds were derated to 1.32ata@2400rpm before June 1943. Some A4 & A5 Jabo versions may have remained at the derated limits by decision of the unit mechanics. Some A4 & A5 jabos may even have been equipped with older BMW801C2 engines due to shortages of 801Ds.

(I'm trying hard to get this BMW801 boost rating story together but, it isn't easy. http://forums.ubi.com/images/smilies/blink.gif The above account is subject to revision as new info becomes available. Crumpp (Kettenhunde) has been a great help in piecing the picture together. If you have questions, try to contact him through PM here, or in the Fw190 Consortium.)

VW-IceFire
10-22-2005, 09:56 PM
Originally posted by Grey_Mouser67:
Problem with books are, once one error gets published, it tends to get copied over and over and over.

I can't say what the A-4 had in real life, but I can find scores of errors printed in books...the most notable one, due to my fancy for the aircraft, is the speed of the P-38L listed as 414...a common error that has been copied to several books....books just use other books as resources and references.

Oleg must make choices about what data he uses because there is much contradictory. If for some reason, he chooses to boost the A-4 I hope he inserts and A-2 and/or A-3 for replacement. The A-4, as modelled, is basically an A-3 afaik.
Too true!

Lots of Spitfire publications list the LF models as being clipped wing types. Or rather suggesting that the clipping of wings meant that it was a LF model. This is not true. LF, F and HF refered to the types of engines used...but this error is reprinted in many locations.

alert_1
10-23-2005, 06:26 AM
OK, it's somewhat confusing, but can anyone post horsepower nominal output for Fw109A4 we hae in the sim? I always thought that it should be 1600/1780 (for 1 min notleistung)?

Viper2005_
10-23-2005, 10:24 AM
C3 (high octane) fuel already has a fairly low detonation point, thus it doesn't require anti-detonants (much like American 150 octane).

B4 = 87 octane
C3 = 96 octane

Octane numbers are much misunderstood.

In the 1920s it was discovered by Ricardo et al that different hydrocarbons had different performance when used in Otto Cycle internal combustion engines.

Fuels were tested using a variable compression ratio engine. The compression ratio was increased until the fuel started to mis-behave (pre-ignition, knock, detonation etc). The highest compression ratio which could be obtained was then used as a basis of comparison. However, some engines are better than others, so you can't just say "This fuel is good for a compression ratio of 6.5,"

As such an alternative reference system was needed.

Fortunately a rather elegant solution was at hand.

Because real fuels are a complex mixture of hydrocarbons (and other things), they have extremely complex combustion chemistry. Therefore, scientists took to testing pure hydrocarbons.

It turns out that iso-octane (C8-H18) does very well under test, allowing high compression ratios to be obtained. Heptane (C7-H16) on the other hand does very poorly.

As such, a reference fuel was constructed by mixing iso-octane and heptane.

This reference fuel was referred to by the percentage of octane it contained, which rather confusingly was called the octane number.

So an octane number of 0 means that the reference fuel contained 100% heptane.

An octane number of 50 means that the fuel contained 50% iso-octane and 50% heptane.

An octane number of 100 means that the fuel contained 100% iso-octane.

Real fuels were assigned octane numbers on the basis of side by side testing with reference fuels on a standard variable compression ratio engine.

This all seemed very reasonable in the early 1920s, when most fuels under test had octane numbers of around 30. It was assumed that 100 octane would never be reached in a practical fuel.

Then Tetra-Ethyl lead came along.

This allowed real fuels to do better than 100% iso-octane.

As such, the octane system broke down. You can't make a reference fuel out of 110% octane.

A new system was needed. This new system is the Performance Number system.

This is a rather crafty extrapolation from the octane system.

Take your fuel, run until the onset of knock. Measure the IMEP.

Now take 100 octane fuel, run on the same engine until the onset of knock.

Performance number = 100*(test fuel IMEP/ 100 octane IMEP)

In aviation, we tend to run at both rich and lean mixtures and it turns out that rich mixtures perform much better than lean mixtures.

As such you really need a pair of performance numbers or octane numbers for your fuel - a lean one and a rich one.

I don't think that there ever was a 150 performance number fuel BTW. Purple avgas is 115/145.

F19Gladiator
10-23-2005, 11:28 AM
Adding in late on this thread I would only like to give some additional info to the above.Also putting in some stuff on later D-9 and the very late Ta152H, as we have them in the sim.

The German speaking part of the forum can find data on MW50 at:
http://www.focke-wulf190.com
Check under "Motoren" and then "Aggregate".Here you find info on both MW-50 and GM1 boost for FW190.
As stated there the Methanol also has an anti-freeze and anti-corrosion effect. Pure water would have a better cooling effect but the disadvantages as per above. Also 0.5% oil to enhance the anti-corrosion effect was added.
There is also info on the later high pressure MW-50 developed for the Ta-152 H-1, which generated about 300hp extra, and that in later built engines the MW-50 could be operated for the duration of 20 instead of as earlier 10 minutes (Ta152 H-1, Jumo 213 E-1, my comment).

According to the book Focke Wulf Ta 152 by Dietmar Hermann:
Deliveries of the high-pressure system for the Jumo 213E-1 was scheduled to start on 29 April 1945.
Further that it can not be verified that any Ta 152H-1 flew with MW-50 or GM-1 in operation in WW2.

Regarding the A-4 and further A-variants check:

http://www.csd.uwo.ca/~pettypi/elevon/baugher_other/fw190.html#

Here it is stated that, Quote:
"In July 1942, the A-3 was replaced on the production lines by the newer Fw 190A-4 version. The main difference was an BMW 801 D-2 engine adapted to use with a MW 50 system for short period engine power increase by injection of a water-methanol (methyl alcohol CH3OH) mixture in the proportion of 1:1. In this way it was possible to raise engine power to 2100 kW for 10 minutes, after which a high probability of engine failure prevented longer use. Due to delays in MW 50 device production, this system was not mounted on the Fw 190A-4 engines, which had the capability to accept this system. It was not used and only A-8 and later series planes would use the advantages of this invention."

In Osprey, Production Line to Frontline No5 Fw190,it is stated that with late built A-8 aircraft, BMW 801D-2, GM-1 or MW-50 option existed. To what extent it was utilized is not revealed.

According to the publication 'Sturmstaffel 1' by Eric Mombeek, Classic Publications: The production of A8 with provision for GM-1 or 115 liter extra tank expected to start in August 1944 (page 32 F-W factory document). (I assume the 115 l tank is the one in the fuselage behind the pilot, which was also used for the MW-50 mix)
The same factory document states that all fighters are to have increased emergency power as from production by June/July 1944. If this was really implemented is another matter, I believe.
The same source tells at page 30 That none of the A-6 or A-7 variants the Sturmstaffel flew had MW-50 installed.
My comment:
An aspect is also the increased weight the MW-50 but also GM-1 boost systems added.
The MW-50 added 155 l fluid of 85Kg plus tank and some pipes, manometer, switches and so on.

GM-1 with 85liter fuselage tank weighed 104 Kg.Total GM-1 weight added +150Kg (140Kg according to a factory document related to Ta152) to aircraft.
(A factory drawing of MW-50 is included in Hermann's book on Ta 152.Page59)
In an aircraft already weighed down with increased armour and cannons any extra penalty was adding insult to injury.

Speed advantage/Performance increase?
Ta152
The Ta152H could reach 749Km/h at 9.500m and with GM-1 760Km/h at 12.500m.I believe these data refer to calculated figures but with armament included.
Also emergency power could not be used fully with the third gear because of weakness in the transmission. Only the later Jumo 213E-1 could cope.
GM1 incremental horsepower boost was 135hp max fro Jumo 213E-1.(Source: D. Hermann's book on Ta152 again.)

Fw190D-9
Equipped with Jumo 213A-1 rated at 1700hp gave 1600hp at 6000m which could be boosted to 2100hp by MW-50.(Source: Osprey Productionline to Frontline No.5)
It is not stated how many D-9 were equipped with MW-50.


Fw190A

As per above max 2100hp for max 10 minutes for the BMW801D-2.(1700hp at ground level normally. Some state 1715 or 1730hp) I don't have at what height or what incremental speed for 2100hp.

Perhaps a graph on the Bf109G6 can give at least an indication, which reveals:
At 2000m +40km/h extra speed with MW-50
At 4000m +70Km/h dito
At 6000m +35Km/h dito

Let's see if the above info adds further to the confusion or if it clearifies something. http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

ZG77_Lignite
10-23-2005, 07:33 PM
Great information Buzzsaw, Faustnik and Viper. Very informative, thanks for the corrections, I am attempting to understand them as I write http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif It is a complex subject, and mis-information is easily spread (I'm a terrible offender for parroting information that may not completely be understood by myself).

luftluuver
10-23-2005, 08:38 PM
When you see Allied fuel, such as 100/150, one is the lean mixture rating and the other is the rich mixture rating. 100=lean, 150=rich, I think.

German fuel was stated at the lower mixture rating.

JtD
10-24-2005, 11:51 AM
I don't think I missed it, but sorry if I did:

How lean is lean and how rich is rich?

Browning50cal
10-28-2005, 07:22 AM
Originally posted by JtD:
I don't think I missed it, but sorry if I did:

How lean is lean and how rich is rich?

"Lean" or "rich" can be stated in terms of an amount of air used in burning a specified amount of fuel. This is called an Air/fuel ratio. Balanced combustion occurs at about 13.8:1 air fuel ratio. This is called a stoichiometric mixture. "Rich" for most aircraft is 12:1 air/fuel ratio. "Lean" for most aircraft is about 16:1 air/fuel ratio. An internal combustion engine usually will not run at all if it is richer than 10:1 or leaner than 18:1. This info is generalized due to differing engine types, fuels and usages, but should answer the question.

JtD
10-28-2005, 07:26 AM
Thank you.

NorrisMcWhirter
10-28-2005, 07:41 AM
Originally posted by Browning50cal:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
I don't think I missed it, but sorry if I did:

How lean is lean and how rich is rich?

"Lean" or "rich" can be stated in terms of an amount of air used in burning a specified amount of fuel. This is called an Air/fuel ratio. Balanced combustion occurs at about 13.8:1 air fuel ratio. This is called a stoichiometric mixture. "Rich" for most aircraft is 12:1 air/fuel ratio. "Lean" for most aircraft is about 16:1 air/fuel ratio. An internal combustion engine usually will not run at all if it is richer than 10:1 or leaner than 18:1. This info is generalized due to differing engine types, fuels and usages, but should answer the question. </div></BLOCKQUOTE>

Just for info, at what ratios would you expect to get harmless 'pinking/knocking' and what ratios would you expect to get serious pre-ignition (i.e. engine damage potential) problems?

Ta,
Norris

Buzzsaw-
10-28-2005, 08:40 AM
Salute

The point at which you might get pre-ignition happening depends on the cylinder head temperature level, and the level of compression.

For example, the Allied Escort fighters typically ran very lean mixtures when at cruising speed during the non-combat periods of their escort legs. (ie. when leaving Britain and crossing the channel, or vice versa)

At low rpms, and boost, the engine cooling systems are efficient enough to allow the running of very lean mixtures without cylinder head temperatures rising to the point that pre-ignition starts to occur. Still prolonged running at these types of mixtures can result in gradual increase in temperature and eventually mild detontation begins. This was manifested in the Allied fighter engines in the form of deposits and fouling on the plugs. This had to be cleared by running the engines at full boost and richness for a couple minutes in each hour.

Once in combat, the richest possible settings were used. That is why the fuel consumption rates at maximum power are so high when compared to normal power consumption rates, or lean setting consumption rates.

Something which I haven't mentioned, is that the fuel/air charge has a cooling effect on the cylinder head as it enters. The richer the mixture, the more cooling. And as mentioned, the cooler the cylinder head, the less chance of premature detonation, and loss of power.

In some aircraft engines, (or auto engines) an intercooler is used to cool the charge even further. This occurs between the supercharger, (or turbocharger) impeller, and entry into the combustion chamber.

Basically a rule of thumb is that the cooler the air/fuel mix is when it enters the combustion chamber, the more power will be produced when it eventually is ignited. There can be a net gain of as much as 15% in power between a normally cooled charge and one which has been run through an intercooler.

Some details on the result of detonation:

Minor detonation, as mentioned above, can result in simple plug fouling and deposits on the cylinder head wall and piston crown as a result of the poor combustion which occurs when the charge fires spontaneously without the benefit of a spark. These deposits will then tend to remain at very high temperatures, glowing, and increase the chance of further detonation. If detonation continues to occur, the areas of the cylinder head, and more particularly, the aluminium piston crown, where the deposits formed, will begin to become superheated as well, and approach molton temperatures. Small molton drops of metal will begin to break free from the piston crown, and can either adhere on the cylinder walls, the piston rings, or on the valve stems or seats. When this occurs, scuffing of the cylinder walls occurs, cracking of the rings, as well as scratching of the valve stem or improper seating of the valves occurs.

Eventually the piston crowns will reach temperatures where the entire crown collapses, and holes form. Meanwhile all the molton metal continues to be deposited in areas where it causes extreme friction and more heat. In this scenario, engine seizure occurs quickly.

All of this can happen in the space of a few minutes, when extremely high RPM's and very high levels of boost are being used in conjunction with insufficiently highly rated fuel and too lean mixtures.

The use of Water injection, direct injection of fuel into the supercharger impeller, or an intercooler will only delay the onset of detonation. The fact is, when running an engine at high RPM's and very high levels of boost, heat is a consistent result, and that heat cannot be dissapated entirely and will eventually overtax the cooling systems.

That is why all max. power settings for aircraft engines have time limits and also why extended running of these engines at full power will result in wear and tear.

(I haven't even mentioned the issue of crankshaft main bearing failure due to the very heavy loads imposed during sustained full power operation. That is another issue... http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif )

luftluuver
10-28-2005, 09:28 AM
You did not mention crankshaft twist either. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Buzzsaw-
10-28-2005, 09:40 AM
Originally posted by luftluuver:
You did not mention crankshaft twist either. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Yep, producing power outta a piston engine is a b*tch... http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif