Aerodynamic Streamlining Template: Part-C

[kach22i]

Originally Posted by ERTW

lifting bodies are new to me. There's a pdf in post #2.

Lifting Body Design - The Rocketry Forum

the flat is on top, and it flies at a large angle of attack. I'll explore any tech transfer to ground vehicles (specifically my malibu

Thanks, the PDF in post #2 goes a long way in explaining how it's supposed to work.

There were another series of lifting bodies from the early 1970's which had flat bottoms and flew in level flight. Which is why these inverted cone ones always look upside down to me.

Lifting Bodies » Galaxy Wire


Collect Aire 1/48 X-24B Lifting Body



Here is the X-24 with the original short nose.
NASA - NASA Dryden Fact Sheet - Lifting Bodies


I built a metal model similar to these in shop class around 1974, I was 14 years old and was crazy about aircraft. It weighed a lot, covered the spars with heavy aluminum foil, it never flew but was always meant to be a static model anyway.

EDIT:
http://s184.photobucket.com/albums/x...%20and%20Ends/

[KamperBob]

Originally Posted by cfg83

aerohead -

Here is a normal 1980's Trans-Am with a spoiler that appears to closely match your template :



Now, if we were to turn the Trans-Am into a "Limo Trans-Am", I would like to know how to apply the template. Assuming I elongate the Trans-Am from the point of max camber, would I (B) keep it in the same place? :



Or (C) be allowed to slide it to meet the spoiler? :



CarloSW2

(C) ... but dictate by roof not spoiler. If the doors are stretched then aft body template fit should be the same as (A). With a flat roof the max point should be that furthest back generally speaking.

[cfg83]

KamperBob -

Originally Posted by KamperBob

(C) ... but dictate by roof not spoiler. If the doors are stretched then aft body template fit should be the same as (A). With a flat roof the max point should be that furthest back generally speaking.

Ok, thanks. Let's use a better example, the Toyota Matrix :



Now, if we were to turn the Matrix into a "Limo Matrix", I would like to know how to apply the template. Assuming I elongate the Matrix from the point of max camber, would I (B) keep it in the same place? :



Or (C) be allowed to slide it to meet the spoiler? :



CarloSW2

[Frank Lee]

Come on now, you know the answers!

It's "B" if you are after that extra count of lower drag and are willing to chop the roof up; and "C" if you want practically the same aero result without all the work and reduced interior volume.

Like I said, nothing sticky-outey (looks like "C" could be back a skosh further too, or pull that spoiler off).

[cfg83]

aerohead -

Would these two elevations be equally aerodynamic? :





CarloSW2

[cfg83]

Frank -

Originally Posted by Frank Lee

Come on now, you know the answers!

It's "B" if you are after that extra count of lower drag and are willing to chop the roof up; and "C" if you want practically the same aero result without all the work and reduced interior volume.

I want aerohead to chime in. Years ago he told me that I couldn't slide the template back on my wagon to "fit the template".

Like I said, nothing sticky-outey (looks like "C" could be back a skosh further too, or pull that spoiler off).

I knew someone would point that out. I think that the spoiler is deliberately sticking out to "trip the flow" (not the right term?).

CarloSW2

[Frank Lee]

I want aerohead to chime in. Years ago he told me that I couldn't slide the template back on my wagon to "fit the template".

I know; I was waiting for him too but he endorsed #332 so I figured "he has spoken". Don't know why he would have said not to slide it back.

I'll chime in on the Limo Template: It would gain just a wee bit of drag due to the increased skin friction from the increased surface area.

P.S. And in YAW the limo will have a bit more "frontal" area.

[skyking]

Originally Posted by cfg83

aerohead -

Would these two elevations be equally aerodynamic? :





CarloSW2

I can answer that for you. The forward and rear shapes are the same, but the wetted area is greater. It will have a little more drag based on that observation.

[aerohead]

Originally Posted by cfg83

aerohead -

Would these two elevations be equally aerodynamic? :





CarloSW2

Frank Lee and Skyking covered the answer as I would have.
You're basically just adding a constant-velocity section in between the acceleration and deceleration sections.
You'll see this done on commercial jetliner fuselage and submarine hulls.McDonnel Douglas has kept stretching the original DC-9 to end up with today's MD-80.
The antithesis would be the Granville Brother's Gee Bee R-1 racer which is one of the shortest but aerodynamically correct forms when viewed in plan.Jimmy Doolittle had to fly this plane bare-footed,as it was very sensitive to control surface corrections and tended to 'swap ends.'
Mair stuck a section like this into his boat-tailed wind tunnel research model.It is nearly identical to a Gavre artillery projectile which you'd see fired from a howitzer at the Aberdeen Proving Grounds and it has an identical drag coefficient of Cd 0.20,before the boat-tailing begins.
PS I should mention,that by extending the body,the SAE break-over angles would no longer be good and unless you had active suspension to raise the car around town,you'd likely suffer a ground strike at the summit of some driveway ramps.Hate it when that happens!

[cfg83]

Frank and skyking and aerohead -

Thanks for the corrections. I am happy that I can slide the template for my wagon :



CarloSW2