Performance characteristics of some wind sensors

Abstract

Summaries of performance data on three wind recorder sensor sets are presented a W.H.O.I.-built vane and cup set mounted on a vector averaging current meter (VAWR), a set of standard orthogonal propellers from the vector measuring current meter (VMWR), and an R. M. Young Company utility cup and vane set (Gill). Data were recorded in a wind tunnel and on a dock. Cup or propeller distance constants were 14.5 m (VAWR), 11m (VMWR), and 3.5 m {Gill). The VMWR propeller distance constant varied little with azimuth. The VPWR cups had the least sensitivity to tilt, less than 5% at 30° compared to 5% and 10% at 20° for the Gill and VMWR. The Gill and VAWR vanes had delay constants of 1.4 m and 2.6 m, damping factors of .67 and .58, and natural wavelengths of 5.9 m and 10 m, respectively, with some doubt of the VPWR vane figures due to experimental uncertainties. That the Gill cups had the least overspeeding was apparent even in the vector averaged wind speeds from the dock intercomparisons. In general, the Gill set is capable of recording vector averaged winds on a buoy more accurately than the VAWR or VMWR set although it is not as rugged mechanically.