Explain this and win the prize!

[Kurfürst]

I looked up it at NACAs archieves, fairly good stuff to read. Didnt read the whole section, but basically it says that most modern wind tunnels mimic the one built during WW1 at Gottingen, and the large ones follow the example of the 2nd generation large wind tunnel at Gottingen, Germany in 1916, again by Herr Prandtl. But I did not find any other *very large* windtunnels big enough to take wholesized aircrafts, even the NACAs own, while being so big that it was capable of taking bombers, was limited to slow flight speed emulations, and so they used it for t/o and landing tests.. I may have missed it, but the others were only capable of aircraft parts tests, not complete a/c. Some details I found on (some of?) the Peenemunde windtunnels, one(?) of the m being described as a rather small (half meter big) w/t, but which was capable of simulating Mach 5!

Good read... http://www.hq.nasa.gov/office/pao/History/SP-440/contents.htm

[MiloMorai]

The Peenemünde Wind Tunnels

A Personal Memoir

Peter P. Wegener

In 1943, on orders from the German Air Ministry, young physicist Peter P. Wegener left the Russian front and reported to the Baltic village of Peenemünde. His assignment was to work at the supersonic wind tunnels of the rocket laboratories of the German Army. Here Wernher von Braun led a team that developed the V-2, the world’s first large rocket-powered guided missile, and laid much of the groundwork for postwar rocket development.

In this fascinating book, Wegener recounts his experiences during Hitler’s time, World War II, and his years at Peenemünde. He tells how he was working one night in August 1943 when the Allies bombed the laboratories, but left the wind tunnels undamaged. The tunnels were moved to Bavaria, and Wegener was ordered to follow in 1944. After the war, the tunnels were moved again--this time to the United States, accompanied by the author and other German scientists. Shortly before the end of the war, Wegener visited Germany’s underground V-2 production plant to retrieve archival material on aerodynamics that had been stored in caves for safekeeping. He describes the appalling history of the concentration camps where SS guards watched over inmates who toiled underground in inhuman conditions and often did not survive. A photoessay enhances this remarkable memoir.


There is a photo of a 109E-3 in the wind tunnel of the Goring Aviation Resaerch Institute in Volkenrode near Brunswick, pg 126 of Bf109 A-E by Radinger/Schick.

[Crumpp]

There is a photo of a 109E-3 in the wind tunnel of the Goring Aviation Resaerch Institute in Volkenrode near Brunswick, pg 126 of Bf109 A-E by Radinger/Schick.

Yep, that would be this one:

The Fw data is probably determined with even smaller model (Ta 152s).

Is a totally false statement.  The FW Data comes off the aircraft.  Not a model.

Crumpp

[gripen]

AFAIK that is a 8m tunnel called A3. Not large enough for lift coefficient measurements.

gripen

[Charge]

"There were modifications withing the Mk IX series, and then there was the superb Mk VIII....."

The VII was stretched a bit and was mounted with 61, 64 or 71 Merlin and was the first to have those two similar radiators under the wings and it had a retractable tail wheel. The VIII was unpressurized variant with Vokes filter with a few different engines.

The tail wheel was however made fixed in IX and the late IX model had again the retractable one where as the other later models again had fixed wheel and again from XII onwards the tailwheel was retractable. Maybe just a feature of parallel development, dunno.

-C+

[Angus]

Many things getting developed at the same time, definately.
Never heard of a Mk VIII with a Vokes filter, can you give some more data on that please?

[MiloMorai]

As if the 109 did not have protrusions, Issy.  

Bulges for the cowl mgs, bulges for the wheels, numerous other little bulges and scoops, an air intake sticking out from the side of the fuselage, 3 radiators (2 coolant, 1 large oil), ADF loop, a retractable tail wheel that was sometimes locked down, extended tail wheel strut, gondola guns hung from the wings, . . . . . . .

[gripen]

Originally posted by Crumpp
The FW Data comes off the aircraft.  Not a model.

The 8m A3 was the largest wind tunnel in the LFA and the wingspan both Ta 152s is more than 10m, even the the short span Bf 109 V24 was too large for the A3, that's why it was tested later in the Chalais-Meudon.

Besides, most of the high speed testing in the LFA was done in the 2,8m tunnel called A2.

And you should still point out what is wrong with the testing with models.

gripen

[Crumpp]

And you should still point out what is wrong with the testing with models.

Did not really press the engineers about it Gripen.  They told me you can't do it and Pyro told me you can't do it.  I did not argue and gave them data off of actual aircraft.

The 8m A3 was the largest wind tunnel in the LFA and the wingspan both Ta 152s is more than 10m, even the the short span Bf 109 V24 was too large for the A3, that's why it was tested later in the Chalais-Meudon.

Wingspan on that E3 is 9.9 meters.  Looks like it has some room to spare Gripen.  At least in the photo.

For the FW-190A8 Finish.  This came out of the original report translated in Valkyrie Publications FW-190A8 Pilots Manual.  It is one of several errors in that book.



It clearly states the finish of the aircraft is "Surface primed and Smooth Painted"  Smooth painted refers to standard RLM semi-gloss aircraft paints.

Crumpp

[gear]

Ok so the topic is about parasitic drag. How much drag is invoved here?

[Crumpp]

Nice arms on that chick...



Crumpp

[Angus]

What's that thing under that thing?

[joeblogs]

The f4f was cleaned up on the basis of full scale wind tunnel tests. NACA made quite a business of this starting in the late 1930s.

-Blogs

Originally posted by Kurfürst
I looked up it at NACAs archieves, fairly good stuff to read. Didnt read the whole section, but basically it says that most modern wind tunnels mimic the one built during WW1 at Gottingen, and the large ones follow the example of the 2nd generation large wind tunnel at Gottingen, Germany in 1916, again by Herr Prandtl. But I did not find any other *very large* windtunnels big enough to take wholesized aircrafts, even the NACAs own, while being so big that it was capable of taking bombers, was limited to slow flight speed emulations, and so they used it for t/o and landing tests.. I may have missed it, but the others were only capable of aircraft parts tests, not complete a/c. Some details I found on (some of?) the Peenemunde windtunnels, one(?) of the m being described as a rather small (half meter big) w/t, but which was capable of simulating Mach 5!

Good read... http://www.hq.nasa.gov/office/pao/History/SP-440/contents.htm

[gripen]

Originally posted by Crumpp
Did not really press the engineers about it Gripen.  They told me you can't do it and Pyro told me you can't do it.  I did not argue and gave them data off of actual aircraft.

Well, the problem is you have claimed things which are not true several times in this thread. I don't see here any evidence that Pyro or somebody else has really said so. And if somebody has said so, I'd like to know why?

Probably over 90% of all wind tunnel testing has allways been done with models and I really like to hear what's wrong with that.

Originally posted by Crumpp
Wingspan on that E3 is 9.9 meters.  Looks like it has some room to spare Gripen.  At least in the photo.

You can easily see from the photo that the wing tips are out of the tunnel, it's the 8m tunnel A3. AFAIK the Bf 109 V24 had short span wing, less than 9m, at least that is the configuration it was tested in the Chalais-Meudon.

Originally posted by Crumpp
For the FW-190A8 Finish...

Not the topic of this thread and learn German...

gripen

[Charge]

Angus, the VIII which where use outside Europe featured a well streamlined Vokes filter which was a much better design than the earlier Vokes or Aboukir filters seen in SpitV. (Aboukir was in fact claimed to be quite good with only 5mph speed loss...)

-C+