ORIGINAL: nicholdime
Hi I'm curious about the difference in drag between various surface finishes and the effect on speed.
For example would there be a ''noticeable'' difference in performance between a molded glider and the exact same model covered in Solartex ? and Solartex after a bit of scuffing from a few landings?
Is there a ''friction coefficient'' for different surface finishes?
I've tried Googling but most references are to technical for me or don't seem to apply at our Re numbers.
Hello nicholdime,
I think the Universal Answer applies here: "It depends." One of the primary effects
of surface roughness is that it affects the transition from laminar to turbulent flow. Less
roughness will tend to delay the transition. The effect of the transition location is a bit
complicated to assess. Laminar flow can make one component of drag smaller, but
turbulence can prevent a laminar separation bubble or delay trailing edge separation,
either of which will probably reduce drag.
banktoturn