Hot-Wire Anemometry: Principles and Signal Analysis

Abstract

Hot-wire anemometry (HWA) is one of the basic measuring techniques used by research scientists and engineers working in fluid mechanics. It is applicable to a wide variety of flows from studies of atmospheric phenomena to investigations of supersonic flows. HWA is an indirect measuring technique based on the heat transfer from a sensing element and for this reason is very sensitive to ambient variations in the temperature. The use of HWA is therefore not usually recommended for the measurement of mean flow properties. However, owing to the fast response and good spatial resolution of the technique, it is irreplaceable for investigations of rapidly varying flows and especially turbulence. Different modes of operation of the hot-wires permit measurements of velocity, temperature and concentration at a modest price and effort which makes the technique attractive and profitable in many situations. In spite of tremendous developments of other measuring techniques over the past two decades, particularly optical techniques such as laser-Doppler anemometry (LDA) or particle image velocimetry (PIV), HWA retains a number of distinct advantages which ensure its present and future use. Hans Bruun has written a comprehensive book which provides a state-of-the-art survey on developments and use of HWA. In many details the book complements the classical monographs of Corrsin (1963), Melnik and Weske (1967) and the more recent contributions to the subject from Perry (1982) and Lomas (1986).