The Potentially Revolutionary Celera 500L Aircraft Officially Breaks Cover - The Drive


Bob Holliston
 


Cameron Garner
 

Here's the official website too: https://www.ottoaviation.com/celera-500l
Fascinating, and it appears they are using every drag-reducing and efficiency trick in the book.
I'm skeptical about the air taxi market, we've seen this show before with the Eclipse 500, though this one might have a better chance, and the economics should be a lot better.



‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Friday, August 28, 2020 12:16 PM, Bob Holliston <bob.holliston@...> wrote:



Kevin R. Walsh
 

I've been loosely following this aircraft since the first pictures were published.  It was interesting to me because it has a very similar fuselage profile to the wheel pant mold I made for my Cozy IV.  That shape was first published by Fabio R. Goldschmied in work he was doing on low drag bodies for airships from the 50s through the 70s.  you can see some of the CAFE Foundation papers on those shapes and research here:

I took the X-35 coordinates and adjusted them to fit the wheels & brakes of the Cozy IV, and did some CFD analysis of it, which you can see here:

And you can see the mold I made on a CNC router here:

and one half of a finished wheel pant in carbon fiber here:

Unfortunately, life got in the way and I still fly my Cozy with no pants.  Well, no wheel pants at least.  I will say that a CFD comparison of drag forces at 180 Knots between this and a "standard" wheel pant shape yielded less than 1% difference in drag just for the pant & gear leg.  Which means that without a true side-by-side comparison between the two on the same plane under the same conditions, we'll never know if I spent a lot of time for nothing.  At least it is fun to talk about when people look and ask why my wheel pants look so funny.

On Fri, Aug 28, 2020 at 9:16 AM Bob Holliston <bob.holliston@...> wrote:



--
Kevin


Vance Atkinson
 

Kev,

Hang in there bud.... If we don't even try stuff you'll never know if it makes a difference. 


Vance Atkinson





On 8/28/2020 12:10 PM, Kevin R. Walsh wrote:
I've been loosely following this aircraft since the first pictures were published.  It was interesting to me because it has a very similar fuselage profile to the wheel pant mold I made for my Cozy IV.  That shape was first published by Fabio R. Goldschmied in work he was doing on low drag bodies for airships from the 50s through the 70s.  you can see some of the CAFE Foundation papers on those shapes and research here:

I took the X-35 coordinates and adjusted them to fit the wheels & brakes of the Cozy IV, and did some CFD analysis of it, which you can see here:

And you can see the mold I made on a CNC router here:

and one half of a finished wheel pant in carbon fiber here:

Unfortunately, life got in the way and I still fly my Cozy with no pants.  Well, no wheel pants at least.  I will say that a CFD comparison of drag forces at 180 Knots between this and a "standard" wheel pant shape yielded less than 1% difference in drag just for the pant & gear leg.  Which means that without a true side-by-side comparison between the two on the same plane under the same conditions, we'll never know if I spent a lot of time for nothing.  At least it is fun to talk about when people look and ask why my wheel pants look so funny.

On Fri, Aug 28, 2020 at 9:16 AM Bob Holliston <bob.holliston@...> wrote:


--
Kevin


Bill Allen
 

The best of luck to them, and anyone bringing 3 new Aviation technologies to market at the same time. New airframe, new engine and new transmission.
Here’s the engine; 

The driveshaft to a pusher propeller has been tried before with mixed results on the BD5, the LearFan and the Grinwalds Orion. Others are available.
 Torsional harmonics are a terrible thing.

Having been involved in developing new power plants in aircraft (Norton Rotary MWE110 and Wilksch diesel) I’m amazed at the ingenuity of the fickle finger of fate in coming up with left-field failure modes that a good writer of suspense fiction couldn’t dream up.

Bill Allen
CZ4, LED, VE.

On Fri, 28 Aug 2020 at 18:16, Bob Holliston <bob.holliston@...> wrote:












--









--


KEN4ZZ
 

Hi Kevin-

Many thanks for publishing the photos and the link to the CAFÉ research page.  When I checked out the page, I noticed the link on it to the reports about the various CAFÉ 400 races thru the years.  As you no doubt know, the first one in 1981 was actually 250 (vs. 400) miles. That's the one in which I flew my - still flying - geriatric VariEze, N4ZZ.  When I checked the report out it was quite the stroll down memory lane, seeing familiar names and tail numbers from nearly 4 decades ago.  It's even easy (for me) to recognize mine in the picture of the Ezes by my first iteration Scimitar prop.  I had cleanly forgotten I'd placed so high, just 2 out of the money.  Good times!

Ken

On 8/28/2020 12:10 PM, Kevin R. Walsh wrote:
I've been loosely following this aircraft since the first pictures were published.  It was interesting to me because it has a very similar fuselage profile to the wheel pant mold I made for my Cozy IV.  That shape was first published by Fabio R. Goldschmied in work he was doing on low drag bodies for airships from the 50s through the 70s.  you can see some of the CAFE Foundation papers on those shapes and research here:

I took the X-35 coordinates and adjusted them to fit the wheels & brakes of the Cozy IV, and did some CFD analysis of it, which you can see here:

And you can see the mold I made on a CNC router here:

and one half of a finished wheel pant in carbon fiber here:

Unfortunately, life got in the way and I still fly my Cozy with no pants.  Well, no wheel pants at least.  I will say that a CFD comparison of drag forces at 180 Knots between this and a "standard" wheel pant shape yielded less than 1% difference in drag just for the pant & gear leg.  Which means that without a true side-by-side comparison between the two on the same plane under the same conditions, we'll never know if I spent a lot of time for nothing.  At least it is fun to talk about when people look and ask why my wheel pants look so funny.

On Fri, Aug 28, 2020 at 9:16 AM Bob Holliston <bob.holliston@...> wrote:


--
Kevin