Quote:
Originally Posted by JulianEdgar
1) OK, so now you can work out the front and rear coefficients of lift for us - based on frontal area and not the deceptive plan view as you did before.
2) and 3) Seriously, you're still applying the template to guess where airflow goes? Even when I have run multiple tuft pics showing the airflow not following the template at all?! That's just very odd.
4), 5) and 6) Yes, what is your point? We're not expecting the car to fly. Maybe read pages 180 and 181 of my book that reference the SAE papers showing how small a lift force needs to occur before it impacts car stability?
7) Yes, lift coefficients have dropped considerably since 1969. What is your point?
8) Page reference please for that specific statement? I am not aware of any such statement in the book.
9) and 10) See above.
11) Lift would in fact be more with the template - repeatedly saying something doesn't make it true.
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1) I'm not interested.If you are, do your own work.You talk of wings. For wings, the plan-view area of chord and span is used.
2-3) The template was created to serve as a Go NoGo. It's derived from technology developed in the 1920s by NACA ( NASA). Its contour is incapable of producing flow separation ( that's why you'd want to use it). If you go ahead and revolve the contour you get a half-body of revolution. The VSPORT is close to the contour. Its profile is a bit mutilated, but flow perturbation would be limited to a very small area. Your tuft study does not have scientific rigor. It's fraught with shortcomings. Automakers don't use it.
4-5-6) Sometimes you appear to be obsessed with lift issues. Given the lift values reported for the Cadillac, Hucho's non-concern with lift was only reinforced. If you're a Princess and can feel a pea under a stack of mattresses, that's your problem. Lift is not associated with attached flow.
* revisit your polar diagrams for wing sections.( A. Silverstein, NACA Report 502, p. 15, 1934 will be a revelation ).
* Hucho, p. 122 ( aspect ratio )
* Hucho, p. 151, Fig. 4.54 (attached flow= lower lift)
* Hucho, p. 217, Fig. 5.4, RAE 101 aerofoil @ 4-degrees offset flow pressure distribution, both sides.
* Hucho, p. 282, Fig. 7.34 ( attached flow = lower lift )
7) what is your point?
8) I can't exit this post to see what I posted in order to reply.
9-10 ) ditto
11) you have measured a half-body in a wind tunnel? If a wing produces zero lift, what would make a half-body produce lift? Hucho presented data for only full bodies of revolution being tested, which is not germane to half-bodies. The virtual aspect ratio for a half-body isn't even 0.3, due to transverse curvature. It would be best characterized as two wingtips joined together. Wing circulation strength is function of shape, velocity, and 'orientation' ( angle-of-attack ). You are speculating about the template's ability to generate lift. An extremely contextual subject.