Time-resolved near-wall hot-wire measurements: Use of laminar flow wall correction curve and near-wall calibration technique

Abstract

This work describes the use of the laminar flow wall correction method and near-wall calibration technique to account for the influence of wall effects on near-wall hot-wire measurements thereby enabling the realization of a true instantaneous velocity field. Most previous works for near-wall hot-wire correction have only concentrated on obtaining the true mean velocity. Experiments were carried out with different wall substrates in both turbulent channel and boundary layer flows. The corrected instantaneous velocity is evaluated in terms of the higher order moments of fluctuation and their respective distributions for comparison to published works in the literature. There is good agreement between results which supports the use of the said methods on near-wall hot-wire measurements to obtain a true instantaneous velocity field.