The non-real-time explicit data analysis method of crossed hot-wire anemometer measurements including tangential cooling velocity correction

Abstract

An explicit, non-real-time method of analysing crossed-sensor hot-wire anemometer data to obtain the two mean velocity components and three Reynolds stresses, as well a their turbulence spectra, is proposed. Equations which explicitly relate the mean velocity components and Reynolds stresses in laboratory coordinates to the mean and mean square sensor output voltages in three distinct stages are derived. The method was verified satisfactorily by comparison with single-sensor hot-wire anemometer measurements and Klebanoff's data in a zero pressure gradient turbulent boundary layer flow. It includes the cooling effect of tangential velocity component in a fixed-angle calibration method and is much simpler than the tedious variable-angle calibration method. The cooling effect of tangential velocity component in a crossed wire is not negligible, especially in high turbulence flow, unsteady flow, flow of unknown mean direction and measurements with a fibre-film probe.