Turbulence Statistics Studies at Trombay with a New Wind System

Abstract

An electronic wind analysis system used for turbulence studies at Trombay has been devised for computing the standard deviation of wind direction fluctuations by measuring the accumulated value of the displacements of a wind vane during a predetermined interval and the number of reversals of wind direction during the same interval. Median values of observed standard deviations of wind direction fluctuations have been classified according to wind speed, wind direction and time of the day. It is observed that local obstructions have a major effect on the standard deviations, which almost double in magnitude when the wind vane is downwind from an obstacle. A diurnal cycle in turbulence intensity has been observed.