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Old 02-21-2012, 09:45 AM   #260 (permalink)
KamperBob
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Join Date: Dec 2009
Location: Somewhere USA
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Black Stallion - '02 Toyota Tundra 4WD xCab

Half Pint - '06 Yamaha XT225
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Quote:
Originally Posted by ERTW View Post
so...21 hours later...I realized how to drastically cut calculation time.

Results for a sharp nosed revolved template - 295 N total drag => Cd = 0.178
The frontal area is 3.0656 m^2 (60" tall, 5" ground clearance)
air speed is 30 m/s (108 kph or 67 mph)
air density at 20C is 1.204 kg/m^3

I realised that from 70% to 80% of the template is a straight section, whereas I use a curve. Phil, if you were expecting a lower Cd, I strayed from the template, as you can see, and this is what I got. This software has good correlation. I didn't want to go beyond solid models and get into surfaces, so I'll leave it at that.

It's expected, and still pleasant confirmation, to see the surface pressure *increases* near the very tip of the tail. I made the nose sharper because there was a large high pressure area on the blunt nose.

Tomorrow will be an interesting day at the University of Toronto


Thanks, dude! Now I'm really looking forward to how this compares with your prismatic template model.

Your earlier point, ERTW, about modeling spheres as known problem solutions is actually a great idea!

So what was the trick for cutting computation time?
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Last edited by KamperBob; 02-21-2012 at 09:46 AM.. Reason: typo
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