Fluctuating heat transfer from hot wires in low Reynolds number flow

Abstract

An estimate is obtained of the heat transfer from a constant-temperature hot wire in a two-dimensional low Reynolds number flow (R [Lt ] 1). The flow has a small sinusoidally fluctuating velocity superimposed on the mean velocity. For the fluctuating components it is shown that at low frequencies the heat transfer is in phase with the velocity, the magnitude of the heat transfer being given by the result for steady heat transfer, but at high frequencies the heat transfer lags behind the velocity, the relative magnitude of the heat transfer decreasing as (frequency)−1.