Topic: Split's wind tunnel test data
A while back Split did some tests with Nerf darts in a wind tunnel to figure out their drag coefficients. The following conversation is copied verbatim from IRC logs.
Jun 12 21:25:04 <Split> just looked up my results from last semester
Jun 12 21:25:55 <Split> standard deviation between darts with different lengths ranging from 1" to 2.5" was only .006, average ~.245
Jun 12 21:26:15 <btrettel> What's this? Drag coefficient?
Jun 12 21:26:20 <Split> yeah, sorry
Jun 12 21:26:24 <btrettel> Interesting.
Jun 12 21:26:34 <btrettel> Good to hear, I guess.
Jun 12 21:26:49 <btrettel> I need to take more measurements. I guess I'll do that next weekend.
Jun 12 21:26:52 <Split> too small of a sample to draw any large confidence, but it's better than nothing
Jun 12 21:26:57 <btrettel> Definitely.
Jun 12 21:27:27 <Split> my computer is running frustratingly slow today
Jun 12 21:27:41 <Split> mozilla freezes if i type more than like 30wpm
Jun 12 21:28:51 <btrettel> That's odd.
Jun 12 21:29:33 <Split> slug tipped darts had average drag coefficient around .2505, molded domes around .2316
Jun 12 21:30:08 <btrettel> I measured about 0.35 for my slugs.
Jun 12 21:30:17 <btrettel> But I only did about 10 shots.
Jun 12 21:30:41 <Split> these are in a wind tunnel
Jun 12 21:30:46 <btrettel> Wow, nice.
Jun 12 21:30:49 <Split> not calculated from shots
Jun 12 21:31:00 <btrettel> I was thinking about making a small wind tunnel for testing darts.
Jun 12 21:31:05 <btrettel> Did you use a real wind tunnel?
Jun 12 21:31:29 <Split> yeah
Jun 12 21:31:42 <Split> 50k lines of data
Jun 12 21:32:12 <btrettel> Crazy.
Jun 12 21:33:46 <Split> the data also suggested that there was a somewhat significant (5%) difference between drag coefficients of slugs with painted tips and slugs with no paint on them
Jun 12 21:34:11 <btrettel> Higher with paint?
Jun 12 21:34:16 <Split> yeah