Convair XF-92A Air intake -the definitive answer

[John R]

When the XF-92A was re-engined with an afterburning engine was the size of the air intake changed to cope with the extra airflow?

Also does anyone know the diameter of the intake(s)?

I'm building anAirmodel XF-92A and the intake looks too small

John

Edit: August 18

to save anyone scrolling down I received the following definitive answer from the National Museum of the United States Air Force.

At your request, our restoration team took the following measurements of the XF-92A:

Intake exterior = 203/4 inches
Intake interior lip =19 3/4 inches
Distance lip to splitter =10 3/4 inches

Width/ Diameter at wing leading edge t fuselage tangent point =66 inches

In addition, you can find an excellent photo walk-around of the XF-92 posted on the Dayton Area Plastic Modelers Society's web site at http://daytonipms.com/Walks/XF-92/convair_xf.htm.

Edited August 18, 2015 by John R

[e8n2]

From the books that I have read and the photos I have seen, the size of the intake never changed. Sorry I don't have anything immediately at hand to tell you the size of the intake.

Later,

Dave

[pigsty]

An afterburning engine doesn't, of itself, increase the airflow it needs, because the extra thrust comes from burning extra fuel downstream to use up the oxygen that wasn't burnt in the main part of the engine. So the intake wouldn't need to be any bigger. Can't help on the actual diameter, I'm afraid.

[Space Ranger]

I can't find any reference to the size of the XF-92A intake, either. If it helps, the external diameter of the Olimp kit's intake at the very tip of the nose is 0.32 in, which scales to 23.04 in on the full-scale article. I'm betting that the real thing had an external diameter of 24 inches. But it never changed over the life of the aircraft.

[John R]

Thank you. Whilst my experience of Olimp products leads me to treat any of their stuff with suspiction that figure does tie in with the drawing in the Airmodel kit and my best guess from looking at pictures of the a/c.

The Airmodel kit does not match the drawing supplied with it. Details here if you are interested

http://www.britmodeller.com/forums/index.php?/topic/234986765-convair-xf-92a-airmodel-vacform-172/

Pigsty

I was led to believe that the engine was uprated as well as having an a/b fitted hence the thought about increased airflow. It is probably perspective but the diameter seems to vary depending on which photos you look at.

John

[John R]

Just found a video of the XF92A in flight with an almost perfect side view - a rough measurement seems to indicate that the intake was about 18 in in diameter. Aaah!

[pigsty]

Pigsty

I was led to believe that the engine was uprated as well as having an a/b fitted hence the thought about increased airflow. It is probably perspective but the diameter seems to vary depending on which photos you look at.

John

Even then, the first change is usually to increase the compression ratio and/or the turbine temperature. Changing the mass flow can mean redesigning the engine, its mountings, accessory parts, and a good proportion of the airframe. Mind you, I'm no expert on the XF-92, so who knows?

[John R]

I emailed the Museum of the Air Force if they knew the actual size and they went out and measured it and the fuselage diameter for me. the answer is in an edit to the original post.

Result!

Edited August 18, 2015 by John R

[gingerbob]

Bravo to them!

By the way, I was going to say that this was the winner of the "most esoteric question" award for the week, but I didn't want anyone to be offended- I like esoteric questions.

bob

Edited August 18, 2015 by gingerbob

[John R]

Nerd, Geek,Anorak? Guilty as charged I'm afraid.

Actually there some inaccuracies that don't seem to affect the look of a model but with this item on this model I think that it matters even though the range of values from kits, plans and drawings only covered a few mm.

John