Dynamic response of a hot-wire anemometer. Part I: A marginally elevated hot-wire probe for near-wall velocity measurements

Experiments were carried out to generate a known near-wall fluctuating flow field for the purpose of quantifying the dynamic response of a marginally elevated hot-wire probe. It is found that the dynamic response of the hot wire is dependent on both the wire's height ( h ) above the wall substrate and the convective velocity at the wire's location. Both larger values of and smaller values of h improve the dynamic response of a near-wall hot wire. Further experiments were also performed to investigate the effect of the thermal conductivity of the wall substrate on the response characteristics of the hot wire. A thermally more conducting material for the wall yields a better response hot-wire probe for near-wall velocity measurements.