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Old 02-25-2012, 10:03 PM   #267 (permalink)
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Phil, do you have a front view and a plan view of the template? I don't think I'm getting the shape right. I set ground clearance at 10% of the body thickness with sharp edges and the Cd is coming in at 0.275 :/ Do you have a solid model?

I've also taken a 4:1 rear body with a 1:1 front end (same length as a 2.5:1 ellipse) which comes out to Cd 0.247. Using a 6:1 rear body (used to model dolphins) only dropped it to 0.243. Both had a 10% fillet and 10% ground clearance. What do you think?

edit: I rounded the bottom edge (R5" or 10%)...Cd 0.191, CL ~ 0.055. Sharp leading edges are a no no! I want to protrude the nose a little into the wake, and sharpen up the trailing edge. I believe it "wants" a 20% radius on the leading edge, and ~12.5 max angle. I think 25% ground clearance is closer to your template (and helps get it above the earth's boundary layer). I'll report it asap.
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Last edited by ERTW; 02-26-2012 at 12:48 AM..
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