Lippisch Projects P.12, 13 and 14

[Justo Miranda]

Speculative variant of the Lippisch DM-2 powered by two HeS 011 turbojets

 

[richard B]

Thank you .

 

[Dagger]

While clearing out old paper article that I forgot I had, I found one that seemed worth scanning and posting.

In another topic there has been some discussing years ago on a Lippisch P13 drawing that appeared in Lippisch book "Ein Dreieck Fliegt" as well as in Dabrowski's "Überschalljäger Lippisch P13a und Versuchsgleiter DM-1",
see https://www.secretprojects.co.uk/th...s-of-the-third-reich.25158/page-2#post-299147
but I think this is a more suitable topic to post the article, which has a similar but much clearer and detailed drawing that is moreover coloured. Even if it is not entirely correct, it looks great......

The article was written by Dabrowski and appeared in FlugRevue of September 1998:

 

[klem]

Re: Lippisch P.12 and P.13 projects

IF not a fake (And that's really difficult to prove!), it's quite clearly not a real
aircraft, the canopy would be recognisable in the stills otherwise (Don't think,
they would have used such an aircraft for blind-flying training ! ). And the
landscape doesn't look suited very well for a real airfield, does it ? Could be
a model test by the Lippisch team of course, but be aware, that, instead of photo-
shopping such a film, it's much easier to build a flyable scale model and make a
b/w-film with it. Alexander Lippisch did a lot of aerodynamical research, but
after the war, Convair still had to do quite a lot of work, to make their deltas
supersonic. Would it have been necessary, if the "P.13a" already was a "ready-
to-use" supersonic fighter, as often is claimed today and in the title of that film ?

Hi,Jemiba.Following the new posts today on this thread. I re-read everything that was posted before and that's when I saw that you were talking about the IOWA university film, I have it and you can clearly see the launch pad for the Lippisch models.

 

[klem]

Testing of Lippisch aircraft models in Vienna around 1944,pictures taken from a video.

 

[T. A. Gardner]

I've noticed one thing that has never been pointed out about the P 13 design. It is definitely a subsonic aircraft based on the engine. The ramjet proposed and shown in every drawing lacks a supersonic shock cone and inlet for the engine. It is highly unlikely that the P 13 could have gone sonic without losing engine power and likely would have lost power during transonic acceleration.

I don't think the Lorin ramjet design from which the P 13 gets its engine, would have worked at supersonic speeds in any case.

 

[Justo Miranda]

I've noticed one thing that has never been pointed out about the P 13 design. It is definitely a subsonic aircraft based on the engine. The ramjet proposed and shown in every drawing lacks a supersonic shock cone and inlet for the engine. It is highly unlikely that the P 13 could have gone sonic without losing engine power and likely would have lost power during transonic acceleration.

I don't think the Lorin ramjet design from which the P 13 gets its engine, would have worked at supersonic speeds in any case.

In the first designs there were such structures to cushion the shock in air intake, but later they were eliminated because they generated too much drag.

 

[T. A. Gardner]

In the first designs there were such structures to cushion the shock in air intake, but later they were eliminated because they generated too much drag.

Well, without them, the P 13 wasn't going to go sonic. I suspect that Lippisch simply didn't have enough data to design a true supersonic fighter plane. The designs you show simply show variations on a plain inlet that wouldn't work in the capacity for a supersonic ramjet.

Inlet cone - Wikipedia

en.wikipedia.org

https://www.smithsonianmag.com/air-space-magazine/how-things-work-supersonic-inlets-35428453/

You need an inlet cone or ramp that is variable to allow for subsonic air to enter the inlet and supply the engine. Without that, the plane's engine stalls and flames out. Also, with ramjets of the early post war period that were supersonic they were limited to about a 4G maneuvering envelope to prevent flow disruption at the inlet.

This was a problem on many early jet and ramjet engine designs. The Me 262 suffered this on its maiden flight when both BMW 003's compressor stalled in a shallow turn, something BMW hadn't designed for because they didn't know about it at the time.

 

[Justo Miranda]

Well, without them, the P 13 wasn't going to go sonic. I suspect that Lippisch simply didn't have enough data to design a true supersonic fighter plane. The designs you show simply show variations on a plain inlet that wouldn't work in the capacity for a supersonic ramjet.

Inlet cone - Wikipedia

en.wikipedia.org

https://www.smithsonianmag.com/air-space-magazine/how-things-work-supersonic-inlets-35428453/

You need an inlet cone or ramp that is variable to allow for subsonic air to enter the inlet and supply the engine. Without that, the plane's engine stalls and flames out. Also, with ramjets of the early post war period that were supersonic they were limited to about a 4G maneuvering envelope to prevent flow disruption at the inlet.

This was a problem on many early jet and ramjet engine designs. The Me 262 suffered this on its maiden flight when both BMW 003's compressor stalled in a shallow turn, something BMW hadn't designed for because they didn't know about it at the time.

Most of Alexander Lippish's research was concentrated on obtaining a stable delta wing in all flight conditions. I don't think he was interested in the problems of transonic flight. The poor aerodynamic conception of the Convair XF-92 and YF-102 prototypes reveals its shortcomings.

 

[CaseyKnight]

Re: Lippisch P.13A unknown version

From "The ultimate flying wings of the Luftwaffe"

Impressive performance, a ramjet that can work as low as 200 mph and with a power/weight ratio for a 45˚ climb is quite impressive. Even if the plane had to accelerate a bit before increasing the climb angle to 45˚ is quite remarkable.

 

[T. A. Gardner]

Impressive performance, a ramjet that can work as low as 200 mph and with a power/weight ratio for a 45˚ climb is quite impressive. Even if the plane had to accelerate a bit before increasing the climb angle to 45˚ is quite remarkable.

That's a Lorin-type ramjet. These are subsonic in nature and more of an athodyd than a true ramjet.

Lorin Ramjet

An early Lorin ramjet on a truck for testing.

So, a P 13 using this type of ramjet is pretty much going to be subsonic in all flight regimes.

 

[T. A. Gardner]

Most of Alexander Lippish's research was concentrated on obtaining a stable delta wing in all flight conditions. I don't think he was interested in the problems of transonic flight. The poor aerodynamic conception of the Convair XF-92 and YF-102 prototypes reveals its shortcomings.

It shows the difficulty in getting an aircraft into supersonic flight at the time. Convair did briefly consult with Lippisch, but I'd say 98% of what they did was internally engineered or done with consultation of the NACA. I'd also agree that Lippisch was likely more interested in researching and designing a delta wing than on building an actual combat capable aircraft using one. Like many late-war advanced German projects, it had to be given at least a veneer of plausible combat use to get any funding. I'm sure Lippisch, like other research engineers simply added some gibberish about it being an "interceptor" or whatnot to the proposal to get the cash.