Quote:
Originally Posted by ERTW
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 20°C 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?