Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Aerodynamic Streamlining Template: Part-C

Bicycle Bob · 08-01-2009, 02:20 PM

[QUOTE=aerohead;119009]---- The template respects streamline flow with an economy of structure and literally guarantees attached flow,at least if you don't cheat the minimums.----------- YOU CAN make the body with higher fineness ratio,I just want everyone to understand that there will be a small penalty to extra skin friction.

I agree that it is good to avoid extra skin friction, but when only one study suggests that flow can stay attached to a shape at 2.5 : 1, and hundreds of tests at a more suitable Reynold's number disagree, I want to see some tuft tests. In the NASA tests for streamlining trucks, you can see a tailcone extension eliminating a Kammback, while increasing the angle a bit, and the tell-tales show separation there, at an angle that is still less than this "ideal."

08-01-2009, 02:20 PM	#32 (permalink)
Bicycle Bob EcoModding Apprentice Join Date: May 2008 Location: N. Saskatchewan, CA Posts: 1,805 Appliance White - '93 Geo Metro 4-Dr. Auto Last 3: 42.35 mpg (US) Stealth RV - '91 Chevy Sprint Base Thanks: 91 Thanked 459 Times in 327 Posts	A lonely messenger [QUOTE=aerohead;119009]---- The template respects streamline flow with an economy of structure and literally guarantees attached flow,at least if you don't cheat the minimums.----------- YOU CAN make the body with higher fineness ratio,I just want everyone to understand that there will be a small penalty to extra skin friction. I agree that it is good to avoid extra skin friction, but when only one study suggests that flow can stay attached to a shape at 2.5 : 1, and hundreds of tests at a more suitable Reynold's number disagree, I want to see some tuft tests. In the NASA tests for streamlining trucks, you can see a tailcone extension eliminating a Kammback, while increasing the angle a bit, and the tell-tales show separation there, at an angle that is still less than this "ideal."