Quote:
Originally Posted by aerohead
Book,'Aerodynamic Drag,' by Sighard Hoerner,self-published,might be a source for that data.
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The closest thing I could find to a head fairing was from Hoerner's drag table for landing gear (all data from NACA (now NASA))
*A wing with 1/2-retracted Goodyear Aerowheel had Cd 0.19.
*When the best fairing was placed behind it,the drag dropped to Cd 0.10.
*This is a 47.3 % drag reduction.
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*Between Hoerner's book,and TECHNICAL AERODYNAMICS,by Karl D. Wood,Cornell University,it looks like the presence of an open cockpit can increase fuselage drag from 41.3% to 87.5%,depending on the case specific application.
*A windscreen can add another 33% drag.
*A fully-enclosed canopy of best design,with no more frontal area than 10% of the host fuselage frontal area added 8.5% overall drag.
*The addition of the two wheels and the affect of ground proximity appears to add drag on the order of 0.0436 to a fuselage Cd measured in free-flight.
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*I looked at Craig Vetter's 1981 Kawasaki,KZ 250 project and in plan-view measure a chord-to-thickness ratio of 3.333,or 30% thickness.
*According to Hoerner,the 'ideal' section achieves the drag minimum with 25.5% thickness.(NOTE the difference between Vetter's and 'Ideal' is so statistically insignificant that I will chime in with Craig's comment that you can experiment all you want,but you'll end up doing essentially what he's done.It's just borne out of the experimental data).
*Jean Andreau's 1937 Cd 0.201 Peugeot 405 used 3.781.
*The 1951 75cc Moto Guzzi Minimotor LSR streamliner utilized the 3.92 ratio.
*So too for the 1957 MG EX 181 LSR streamliner.
*Volkswagen's 1981 Cd 0.14 'Flow' body was very close (3.847).
*Porsche's 1982 956 canopy is based upon a 3.617 section
*Daihatsu's Cd 0.163 UFE-3 is 3.866.
*The 2012 Edison-2 is based upon a 3.351 section.
*An effective fineness-ratio for Craig's KZ is 2.698:1 (almost identical to Paul Jaray's 1922 patented 'Kombination-form' roof section in plan-view.