Measurement techniques and problems: II. Resolution issues
Kolmogorov scale h (eddy size, log law region)
- lowest Re h ~ 10 -4 m
- highest Re h ~ 10 -6 m
-
Attenuation of Hot Wire response for k L > 1 with L / h = 1 (Wyngaard, 1968)
- HW L = 0.24 mm
- actual L / h ~ 1 - 270
- best case attenuation of k > 2000 / m
Preston probes for skin friction measurement
- height ~ 1, 0.5 mm
- calibration in Superpipe