Hot-Film Turbulence Measurements in Water Flow

Turbulence measurements in water have been carried out using hot-film anemometers in a circular conduit. A circulating water loop was specially designed for such measurements. The calibration of the anemometers and measurements of turbulence intensities and energy spectra were made in this water-loop. Two special types of hot-film probes were tried: (1) wedge-shaped probes must take into account a drift of the characteristics which can be corrected experimentally; and (2) conically shaped probes which do not present the disadvantage of drift seem to be of great use for measuring longitudinal velocity components. A study of the heat transfer between such a probe and the water led to the establishment of a non-dimensional relationship. Measurements of relative intensities and energy spectra were carried out and compared with those of previous authors in air and for dynamically similar flows. This comparison proves that hot-film anemometry methods can be used, under controlled conditions, for turbulence measurements in water with the same degree of accuracy as that found for measurements in air.