Japanese jet flying wing study

[sienar]

Sounds pretty notional but maybe something more has survived?

"Captured documents indicate that, as far back as 1941, the Japanese were considering jet-propulsion as a means of powered flight, and that by early 1942 they had developed the theory of a turbo-jet power unit, had the basic design of such a unit already completed and had evolved the design of an aircraft— of the flying-wing type - powered by two turbo-jet units"

"In the fields of turbo-jet propulsion research, a captured document reports on the results of experiments during the period April 41 - March 42 as carried out at the Naval Air Technical Depot, presumably at Yokosuka. That document, stated to be the sixth report on the sub­ject, includes & theoretical treatment of pressure and temperature distribution in & turbo-jet unit together with an analysis of the thermodynamics of such a unit. The report concludes with a schematic diagram of a turbo-jet unit, together with a tailless aircraft powered by two such units."

From German Technical Aid to Japan Military Intelligence Service

 

[windswords]

Hidemasa Kimura was experimenting with tailless aircraft His HK-1 glider made it's first flight in January 1939, followed by more advanced designs (Ku-2, Ku-3 & Ku-4) through April 1941. Data from these flights was used in the development of the J8M rocket plane.

Japanese jet development began in 1942. Initial work was done by the First Air Technical Arsenal and employed centrifugal compressors. The first Japanese jet engine was the TR-10. The TR 10 produced 770 lbs. thrust. The TR-12 was the next of the series and represented an improved TR-10 with four axial compressor stages added; thus following a compressor development pattern similar to the German Heinkel engines. The TR-12 was considered to be too heavy. The TR 12B followed with a weight of 770 lbs. This latter engine was abandoned in March 1945 in favor of the Ne-20. It was found that the TR-12B lagged considerably behind the development of the Kikka airframe. In May 1944 photographs of the BMW 003 arrived by submarine. From these photos and a single cut-away drawing the Ne-20 was developed.

So in response to your post, the timeframe is right - Japanese jet engine program started in 1942 and tailless aircraft experiments started in 1939. But the Japanese did not consider a full flying wing configuration like the Ho-229 - only tailless aircraft like Kimura's gliders and the J8M derived from the Me-163.

 

[sienar]

So in response to your post, the timeframe is right - Japanese jet engine program started in 1942 and tailless aircraft experiments started in 1939. But the Japanese did not consider a full flying wing configuration like the Ho-229 - only tailless aircraft like Kimura's gliders and the J8M derived from the Me-163.

Its from a US military report written in Sept of '45. I would take the line that a captured report depicted a twin jet flying wing to be accurate.

 

[newsdeskdan]

So in response to your post, the timeframe is right - Japanese jet engine program started in 1942 and tailless aircraft experiments started in 1939. But the Japanese did not consider a full flying wing configuration like the Ho-229 - only tailless aircraft like Kimura's gliders and the J8M derived from the Me-163.

Its from a US military report written in Sept of '45. I would take the line that a captured report depicted a twin jet flying wing to be accurate.

On p281, that same report (September 25, 1945, author: Colonel Alfred McCormack) calls the Me 163 B a flying wing...

 

[windswords]

On p281, that same report (September 25, 1945, author: Colonel Alfred McCormack) calls the Me 163 B a flying wing...

I wondered if that were the case. A tailless aircraft is technically not a flying wing, but very close to it. Perhaps the Colonel confabulated the rocket powered J8M "flying wing" with the twin engine Kikka to get the twin engine "flying wing"?

 

[Orionblamblam]

I wondered if that were the case. A tailless aircraft is technically not a flying wing, but very close to it.

Keep in mind that early on, the definition of "flying wing" was vague. Northrops's first named "flyign wing' was not what we would not call a "flyign wing.'

 

[Maveric]

Do you have drawings of the Kimura Ku.3 and Ku.4?

 

[windswords]

Do you have drawings of the Kimura Ku.3 and Ku.4?

 

[Maveric]

Many thanks windswords!!!!!!!

 

[hesham]

From my dear Boxkite.

 

[riggerrob]

When you visit the The Wing Is The Thing (TWITT) website, you will see a bewildering variety of “flying wings.” A purist would only acknowledge wings that conceal: crew, engines, payload, etc. completely inside a single horizontal airfoil. That airfoil (wing) might be a simple, straight up plank (Backstrom) with zero sweep or taper. At the other end of the scale, Concorde’s ogee-curved, low-aspect ratio, Delta also counts as a flying wing from the aerodynamic perspective.
Purists may be offended by canopies, propellers, vertical fins, etc. protruding from their “perfect” wing, but crew and engines do not always scale down small enough to fit completely inside even the fattest of wings.

Bottom line: any flying machin with only one horizontal surface counts as a flying wing aerodynamically.

 

[Silencer1]

Bottom line: any flying machin with only one horizontal surface counts as a flying wing aerodynamically.

Objection!
Dunne swept-wing biplanes have had two horizontal surfaces

Perhaps, we could say "any flying machiine, that has horizontal surfaces placed without any horziontal shift to each other counts as a flying wing aerodynamically"?

Picture from Wikipedia

 

[windswords]

When you look at the Dunne airplanes and the Coanda-1910 ducted fan (yes I know it is not a true jet), you realize there is almost nothing new, at least in concepts in aviation, but new approaches on first attempts.

 

[Silencer1]

Perhaps, it would be more suitable split this thread:
1) about Japanese jet tailless aircraft
2) definition of flying wing/tailless aircraft and related?

Off-topic: When we mention Coanda and Dunne inventions, did we think about origins of their ideas?
There were compressors and turbines in ships and other steam machinery, but what's the origins of biplanes and swept wings?

 

[QAZ]

A bit of a necro, but as some people may visit this thread and be confused, I want to point out what the OP's document was referring to.

https://twitter.com/x/status/1523107328270409729

View: https://twitter.com/QAZ_jpav/status/1523107328270409729


In 1942 Cmdr. Tanegashima submitted a report on the theoretical compound free-piston turbine engine and axial turbojet engine. In this report, he used a turbojet-powered flying wing to calculate his theory, but the plane is not a real design. A copy of the document was captured on Saipan and translated as CINCPAC-CINCPOA Item #9256, and somehow the US intel later interpreted this as a real design.

 

[hesham]

A bit of a necro, but as some people may visit this thread and be confused, I want to point out what the OP's document was referring to.

https://twitter.com/x/status/1523107328270409729

View: https://twitter.com/QAZ_jpav/status/1523107328270409729


In 1942 Cmdr. Tanegashima submitted a report on the theoretical compound free-piston turbine engine and axial turbojet engine. In this report, he used a turbojet-powered flying wing to calculate his theory, but the plane is not a real design. A copy of the document was captured on Saipan and translated as CINCPAC-CINCPOA Item #9256, and somehow the US intel later interpreted this as a real design.

Are you sure about it,never heard ?!.

https://mobile.twitter.com/qaz_jpav