BMW turbojet

[Bruno Ogorelec]

Just saw a BMW 003 jet engine (the thing that just narrowly missed being the world's first production turbojet) in a museum in Prague. It is partly sectioned so that you can see the innards in great detail. A fascinating design.

Its mechanical complexity is rather greater than I would have expected, with a jewel-like crown-wheel and pinion shaft drive from the compressor shaft to the variouls ancillaries like the fuel pump, generator, oil pump etc. etc.

It's got an 11-stage axial compressor, a can-annular combustor and a single stage axial turbine. The combustor is a complex affair with 9 inlets, each with an intricate turbulator. Additional fresh air is added halfway down the combustor through angled blade-like vanes.

Hot gas blows onto the turbine through a very short, simple nozzle.

The turbine has interesting blades, fabricated out of sheet metal. The sheet is bent into airfoil shape and -- apparently -- welded at the trailing edge. Fresh air is pumped through hollow blades for cooling.

No attempt is made to straighten the gas flow after the turbine -- there is just a very simple nozzle to accelerate the flow and that's it.

The whole thing looks quite surprisingly modern -- much more so than the contemporary Whittle designs.

[Tom]

Bruno, Were you lucky enough to take some photographs?

Tom

[ed knesl]

Bruno,

when I was a kid, in very small courtyard near rail station in Brno
was a very tiny museum with only two items on display :

1. Me-262 A2 WOOOW !!!
2. Arado 234 B

both of them had turbojets, if I remember one had Jumos and other
BMW. ( Czechoslovakia was than the Germany's machine shop and
lot of these airplanes were produced there, particulary Me-262 and
Bf-109 , still after the war ).

Recently I searched for these aircraft and curiously - nobody has any
clue what hapened, how and when they disappeared.
Wonder who got a hold of these priceless machines ! Some investigation would be apropriate here.

What were you doing in Prague ?

Ed

[skyfrog]

Just google search and got this link, if Bruno didn't take any photoes, well here they are.

http://www.clubhyper.com/reference/bmw003tb_1.htm

[Bruno Ogorelec]

Tom, idiot that I am, I failed to take a camera, thinking that taking photos would not be permitted. (A day earlier, I was not allowed to take a photo of the inside of the main post office, for instance.)

Horace, yes, this is the engine I saw, only, the one in the Prague museum was partly sectioned, so that you could see plenty of fascinating internal detail.

For instance, the one on the photos has the oil cooler covered with a casing plate, while the one I saw was open. That cooler by itself is a work of art, with about 30 aluminum tubes about two feet long wrapped halfway around the nose of the engine in five rows, with very thin, fine pitch cooling ribs across the tube. I have no idea how such a ribbed tube is produced. Cast? Must have been very expensive.

You should have seen that crownwheel and pinion shaft drive to the ancillaries! Like the old racing motorcycle engines; beautiful.

Ed, I was in Prague with my wife. We went along with the Croatian national women's softball team for the European Championship (my daughter is the main pitcher and 3rd base player in the national team). We took advantage of the preferential hotel rates offered to the competing teams.

We did attend the most important games, but spent most of the time gawking around the truly splendid city. Prague is truly a must for everyone visiting Europe. It's difficult to understand Central Europe if you have not absorbed some Prague. I know it will sound strange to some people, but Prague has more and richer layers of history than, say, Paris.

I spent most of a day at the National Museum of Technology and I can tell you, it can hold its own with any other I have seen. Some amazing exhibits. The problem is that they only have room for maybe twenty percent of the stuff to be exhibited at any given time.

Eighteen flying machines are suspended from the ceiling at the moment, including one of the earliest Bleriot monoplanes, an Etrich Taube, two really pretty Zlin aerobatic craft, a Flying Flea etc. One of the prettiest jet aircraft ever (to my eye), the Albatross L39, is parked on the floor and you can inspect it in detail. (Most of the aircraft are at a separate exhibit at an airport I did not have time to visit -- apparently a lot of WW II aircraft, including Russian Lavotchkins, Lebedevs etc.)

The car collection is no less impressive. As I wrote to Bill Hinote after returning to Zagreb, the range of cars the Czechs produced until WW II boggles the mind. But, they have many others on show, including a Mercedes 540K supercharged straight-eight, two Bugattis, a 1901 steam Serpollet and a 1910 White (a beautiful, beautiful car). Perhaps the most amazing is an 1906 locally made racer with a 5.3-liter flat twin engine and chain drive. A monster!

Smaller stuff is great, too. There's an amazing US-made bicycle with a bamboo frame from the turn of the century, with pretty cast and machined lugs holding the bamboo poles. Some amazing motorcycles from all over the world, including incredibly advanced machines made locally in the 1930s (overhead camshafts, shaft drive...).

My head was spinning after a while.

A thoroughly enjoyable and enriching trip.

[ed knesl]

Bruno,

I wonder if you saw aircraft engines exhibition.
That is realy incredible, all WW II engines and probably most interesting
prewar radials from 3 to 9 cylinders ranging from about 25 to 200 HP.
Most of them were original Czech Walter engines and these were made
as Swiss watch. Incredible machine work on cylinder cooling fins
( no casting rough stuff - all machined out of solid stock ) Very
lightweight powerplants and entire line was spaced by only few HP.

Nothing even close is available nowdays.

Did you drink beer " U Fleku" ?

Yes, Prague is a Mother of all cities.
Next time you have to, I mean, have to visit Cesky Krumlov in southern
Bohemia. A killer town !

[Bruno Ogorelec]

Ed, yes, I saw the engines. Drooled over them, too. The Walters were real gems.

What I also liked was the history of aircraft development told in scale models. Some were really special, like the Esnault-Pelterie monoplane (arguably the first real monoplane aircraft) by the guy who invented the 'reciprocating' pulsejet.

I'd have taken a few cars from that collection home if I could. Especially the 1932 Wikow sports two seater, which looks like it could have given the contemporary Alfa Romeos a run for their money. Amazingly, it looks like having hydraulic brakes.

Ah to be back in the 1930s and to run one of those on the Targa Florio...

I had plenty of very good beer but avoided 'U Fleku' because it not just a great beer place but also a tourist trap. I tried to avoid crowding where I could. Fortunately, Prague is crammed with good pubs.

What amazed me by far the most is the bizarre fact that the city has no fewer than FIVE baseball and EIGHT softball fields.

For those into softball, here's two pictures -- Yours Truly with his favorite softball player somewhere in Prague and the same player in the middle of a pitch at the European Championships. (We placed fourth out of ten; the best we've ever done. We lost a medal by a whisker.) This is very much off topic but I like them. :o)

[steve]

Bruno,

when I was a kid, in very small courtyard near rail station in Brno
was a very tiny museum with only two items on display :

1. Me-262 A2 WOOOW !!!
2. Arado 234 B

both of them had turbojets, if I remember one had Jumos and other
BMW. ( Czechoslovakia was than the Germany's machine shop and
lot of these airplanes were produced there, particulary Me-262 and
Bf-109 , still after the war ).

Recently I searched for these aircraft and curiously - nobody has any
clue what hapened, how and when they disappeared.
Wonder who got a hold of these priceless machines ! Some investigation would be apropriate here.

What were you doing in Prague ?

Ed

You may find this interesting-
I took this at the NASM at Dulles:

[ed knesl]

You have a beautiful daughter, Bruno; congratulations to her and her team. It sounds like a great trip, and you've sold me on Prague. Maybe I'll make it there in a year's time.

Bruno,

Ben needs a new girlfriend.
( Ben is very nice and smart young gentleman - you better think about it )

Ed

[Bruno Ogorelec]

You have a beautiful daughter, Bruno; congratulations to her and her team. It sounds like a great trip, and you've sold me on Prague. Maybe I'll make it there in a year's time.

I do, I do, I know. I am enormously proud. The best thing I've done in my life (to the extent that I have had any influence, that is). She's also very smart, competitive, successful etc. etc. Speaks a heap of languages, shooting to be a good biotechnology engineer... I wish I was her kind when I was her age. Instead, I was a bum.

Ben, Prague is wonderful. Not to be missed. I am certain you'd like it very much. Just ignore the crowds. (It's become a tourist Mecca.)

Ben needs a new girlfriend. (Ben is very nice and smart young gentleman - you better think about it )

Ed, I know. I like Ben a lot. But, my Mirna is 23, going on 24, and very much her own woman. She's quite attached to us and will gladly listen to my (and my wife's) advice but will no longer necessarily follow it. Especially not in the matter of boyfriends, he-he-he...