Experimental study of the aerodynamic perturbations induced by the single normal hot-wire probe positioned normally in the vicinity of a wall

Abstract

The conducted research, though still at the preliminary stage, is a step toward a better understanding of the flow phenomena accompanying hot-wire probes. For the flow in the vicinity of a wall, a potentially non-optimal case was analyzed – a single normal hot-wire probe oriented normally to the surface. According to the results, undisturbed flow, as measured in the absence of a hot-wire probe, was significantly altered in its presence. Differences in the vertical profiles of the velocity magnitude in the upstream direction of up to 40% were observed 0.43 mm from the probe’s longitudinal axis of symmetry, and up to 8% at a distance of 3.73 mm. The lower Reynolds numbers were considered the more complex velocity profile perturbations were present. The highest differences in undisturbed vs. disturbed flow were observed at the level of the wire and below, regardless of the distance from the hot-wire probe.