Crumpp

Well, then you are wrong on the point of air mass flow as others have explained. I am an A&P too, btw. :music_whistling: As for the time...24 secons vs 8 seconds is a few seconds.... A few seconds is subjective but the fuel air flow vs volume of fuel in the metering system can be easily calculated to give a reasonable approximation. Just need a good source on the volume of usable fuel in the system when inverted.

Falke, I think you guys are talking past each other. Both statements are correct depending on the type of engine being discussed. That is correct in a fixed propeller aircraft, automobile engine, and a turbine engine. PLANK/33000 tells us that. However, in a constant speed propeller aircraft, that relationship of air mass flow being proportional to rpm does not hold up under all circumstances. It goes even farther from the mark with a supercharged engine. Just look at the power production for any supercharged constant speed propeller aircraft after critical altitude. You can see that in Table 2, Hooker's Expression shows us that charge flow, air plus fuel is the main relationship. http://www.enginehistory.org/members/articles/ACEnginePerfAnalysisR-R.shtml I think Otto has a point. Rolling upside down should not destroy the engine but neither should intentional inverted flight for more than a few seconds be allowed.

It terms of combat service in World War II, there is no difference. The Bearcat did not enter service before VE Day and it never saw combat in World War II. They all are a "never was" for World War II.

For air racing servers...it would be great. It would ruin any World War II scenario for me as much as the napkin Luftwaffe 46 designs do. It just simply was not a world war II bird.

Fly it more often! What engine settings do you typically use on the P-51?

I think you need to do a DCS repair. My Dora engine goes out quite regularly if I do not fly it by the approved ratings or run it out of MW50. In fact it died at the top of the climb on ACG server today when I had it set at ~3100rpm for the climb out.

It is a Jumo 213 for the Dora 9, which was next on the list after Little Missy.

Yes it was sold to the Collings Foundation. If you wanted pictures of the early project, you should have joined and contributed. Thanks! :thumbup:

Nice find, Keelvra!

A lot less that that. In FW-190A series, the inertial starter is combined into a single unit with the electric generator. Inserting the hand crank for the inertial starter withdraws the brushes from the electric motor. It maybe more of cowling space issue than weight in the Bf-109 series.

Exactly, I think everyone agrees it the VVS data gives good agreement with the RAF flight test's when converted to the same conditions and weight. :thumbup:

The Merlin 61 used and was approved for +15lbs. I do not see how that proves the VVS Merlin 66 curve is only for +15lbs? The VVS Merlin 66 data agrees with the RAF Merlin 66 data at +18lbs.

Укажите, пожалуйста, точно место, где говорится, что давление наддува +15. Yeah, the ground tends to prevent that for everyone. The data is reduced mathematically by the engineers to sea level. Because of that it makes a great point for use to compare performance as that point is not effected by atmospheric modeling. It is mainly just instrumentation error. True airspeed = Equivalent airspeed at sea level. The results above that point are due to atmospheric modeling, which is why I asked you about the specific details of the atmospheric model the VVS was using. Comparing that Equivalent Airspeed the VVS data gives good agreement with the British data for a Spitfire Mk IX Merlin 66 at +18lbs.

Then we can agree that if they do not say they have Merlin 63 and we have NO Evidence of them using +15lbs AND the performance agrees with a Merlin 66 +18 engine.... They probably had Merlin 66 +18 engines. Looks like a duck, walks like a duck etc etc... It is probably a duck. He did not post the entire article, just the charts from it so stop with the childish innuendo's. I have LOTS of Russian data from friends over there including some original TASGI reports. Most of it is snippets and clips. Some of it is even rewritten because the archivist did not have a way to copy it at the time it was viewed (~8 years ago). They poor guy had to copy what was in the reports himself. The performance reported by the VVS at 528kph or 328mph at sea level is only 2.3% behind BS543 in this report: http://www.spitfireperformance.com/bs543.html http://forums.eagle.ru/showthread.php?p=2122488 The British aircraft, BS543 is 150 lbs lighter than the VVS aircraft. Factor that in and the difference between them becomes even less. The VVS data gives good agreement with the RAF examples.

There is no need to continue back and forth over this either, Fredrich. If you wish to believe the VVS could not tell which engine was in their aircraft, I have no issue or desire to persuade you otherwise.

That is the definition of the Merlin 63 Fredrich. It is a Merlin 61 with a Merlin 66 supercharger. The engine data plate will say...MERLIN 63. I am sure the VVS were smart enough to know what engines they used.

Harnessing exhaust thrust was one of those areas of aircraft engineering discipline that came into its own during World War II much like stability and control engineering. Like stability and control engineering, the levels of technical savvy were not always equal. The first real theoretical investigation appears to be Hermann Oestrich Prospects for Jet Propulsion of Airplane with Special Reference to Exhaust Gases. That was in 1932. When the war started, it appears the idea appeared much more than theoretical and everyone started investigating the most efficient way to harness it. The British put up some very good designs and were a leading nation in subsonic aerodynamics. Gates can be considered one of the founding fathers of modern stability and control engineering and his stick force per G criteria is still used today. That does not mean the establishment at the RAE welcomed outside ideas with open arms. Exhaust stacks for individual cylinder exhaust-Jet-Propulsion system.pdf Exhaust thrust thru experimentation.pdf

I agree. However the Merlin 63 is a different designation and I would think the VVS would know the engines they have. Additionally, the performance gives good agreement with the published performance figures for the Merlin 66 series at +18lbs. Look at that document. I do not think it is an original TASGI report at all.

I noticed there was no data on the Merlin 66 Spitfires. Also, are you sure this is a TASGI report? It looks like something a modeling enthusiast might have put together. It talks about post war designs and the aircraft serving thru 1955!! That is a lot for two TASGI reports from 1944 and 1945. The NKVD were good but that good? :huh:

That would be great Kodoss!

DCS's ground behavior is spot on IMHO. Based on my experience owning and flying taildraggers. Each aircraft is a little different. The DCS P-51 and Dora both remind me of a heavier Pawnee. Very honest in their ground handling. The worst taildraggers I have ever flown for ground handling are a Luscumbe 8E and an OV-1 Birddog. Both of those aircraft felt extremely unstable and have a reputation for loving to ground loop. You taxi them no faster than a walk.

The Spitfire Operating Instructions for the Spitfire Mk IX series only clears the Merlin 63 for +15lbs. You can get your own copy, here: http://www.zenoswarbirdvideos.com/Spitfire9_Manual.html

Privet SKR, Ok, You are saying the data is converted to some standard atmosphere. Any idea what those "standard conditions" are in the report? The AIAA publishes a list of "standard atmosphere's" IIRC, there are 37 standard models in common use in that reference atmosphere guide. For subsonic imcompressible flow, the important things do not change much. That being said, it would be nice to see the VVS "standard atmosphere" model parameters. For now, let's move on. The data is within + or - 3% of the RAF Merlin 66 +18lbs data and the Merlin 66 was not using +15lbs as a published Manifold pressure limit....that only corresponds to the Merlin 63 engine 5 minute rating. So that is why SKR, the +15lbs rating is difficult to digest. It was never a rating for the Merlin 66 engine issued by Rolls Royce. It is lower but not by much than the +18lbs so you are saying the VVS de-rated the engine. It would be nice to see the original document! The VVS curve for Merlin 66 Spitfire follows BS 543 closely and is at most only 1.5% behind which does gives good agreement with a Merlin 66 +18lbs aircraft. That leads me to believe it is a Merlin 66 engine as it is labeled but the 15lbs boost limit is still not clear. What would clear it up is the document stating the 15lb boost limit or a VVS Pilot Operating Instructions for the Spitfire Mk IX Merlin 66.

My question is under what atmospheric conditions was the data derived for the USSR Spitfires?

Unless your building a header system and using the low pressure to increase the high pressure velocity... Back pressure is not a good thing to have in an exhaust system. Was that the thinking behind the huge exhaust system on Spitfire Mk I? Kind of short to achieve that effect weren't they?