On Monday, June 12, 2017 at 1:38:22 AM UTC-4, Bret Hess wrote:
Hi, we see lots of mylar gap seals and read lots of discussion of them. Does anyone know of an engineering study that quantifies their effect on sailplane wings or other wings? Nothing pops up quickly in Google. I'm wondering how much science there is to this practice.

I'm hoping for more than anecdotal comments. Saying that top racers all use them doesn't tell us much because so do almost everyone.

Look up any of Richard Johnson's flight tests before and after seals, especially the LS-4. Or any other modern sailplane. There was as much as a 5 point difference.