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Old 01-28-2010, 04:53 PM   #23 (permalink)
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Cont'd from yesterday

Originally Posted by aerohead View Post
(1) Yes,the longitudinal centerline constitutes the ground plane and the vehicle would be scaled to fit with it's wheels on the "ground",and the highest point of the roof aligned with the 12:00 O'clock position.The rest of the roofline is defined by the curve.
(2) The very back of the teardrop is the separation point,so all points ahead of that are in attached flow.
(3) Since all vehicles must have ground clearance,it would be impossible(and unnecessary ) to build a body the full length of the drop,as it would end where intersected by the belly line.
Al is closing the store,I've got to close now,will catch up asap.
I'm trying to pick up where I left off yesterday,but all the original graphics and questions didn't get included in the new"quote".
(3)(cont'd) This 'clock-face' template is more liberal than the "Aerodynamic Streamlining Template",at about 2.78:1 L/D ratio as opposed to 2.5:1.And with the hemispherical nose instead of the prolate ellipsoid,it has more aftbody.It's more akin to the one Darin first posted with "Permanent Metro Kammback." They all will provide attached flow.The 2.5:1 has the least drag,with lowest friction drag,as it has the least "wetted-area"(i.e. skin friction).
The spirit of the clock-face template,is that,in light of it's origins,it could be used with an extremely high degree of confidence to construct a roof-line of any length(or boat tail or trailer )which maintains attached flow,working with virtually no other reference.
This line of reasoning was the foundation for Kamm's,von Fachsenfeld's,Jaray's,Klemperer's,Lay's,Heald's,Re id's,and others development of low-drag cars,including Hucho,for the VW 2000 concept.
Today,university teams are using this form to win solar car and HPV competitions,whether on land or underwater.
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