SIMULTANEOUS TEMPERATURE AND VELOCITY-MEASUREMENTS

A technique for making simultaneous temperature and velocity measurements, required for measuring temperature-velocity correlations used to determine turbulent heat fluxes, and temperature-velocity correlation coefficients, is described. This technique uses a two-component laser Doppler velocimeter (LDV) which gives a direct measure of velocity fluctuations and a 0.64 mum cold-wire which gives a direct measure of the temperature fluctuations. This technique has the advantage over multi-element hot- and cold-wire anemometry systems in that there is no sensor interference between the velocity and temperature sensors, and there are no corrections which need to be applied to the velocity measurements because of temperature influences of the surrounding fluid.