View Single Post
  #300  
Old 04-06-2006, 12:51 AM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Exclamation New Plan -- Prowler

Another Schoolyard Sounder...

OK, folks, I know these 3FNC designs are not the most interesting, but there is a purpose behind them. Especially this one, as it again uses that stepped fin shape to reach the lowest Dv possible with a rocket of this shape and weight. Altitude was not a priority, but keeping it stable and getting the softest deployment possible were priorities.

You will notice a full dozen runs on a single motor, which demonstrates the range for the Dv better than a single run. It took me over two hours to tweak the shape to get those low numbers; even the slightest shift in the fin plot points could alter the Dv by as much as 200% from what you see here (or, the Dv's would easily double to 8 and 10 FPS).

Take this one as an academic study in fin shapes and their respective flight characteristics...

Length: 15.0434"
Diameter: 0.908" (ST-8)
Fin Span: 3.2272"
Weight: 0.822 oz

Average range:

A3-4T.....397'.....4.75-to-6.19 FPS Dv.....576.70 FPS/S.....36" Rod

I think it still makes a great flying design, even if it is just 3FNC...

Enjoy!
Attached Thumbnails
Click image for larger version

Name:  Prowler.jpg
Views: 112
Size:  44.9 KB  
Attached Files
File Type: rkt Prowler.rkt (104.2 KB, 101 views)
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote