Vibration suppression of stepped beams: new designs for hot-wire probes

Local geometric modifications to slender stepped-beam structures are presented to minimise dynamic response under broadband excitation. The particular application in this paper is the sensing wire of a hot-wire probe. Hot-wire anemometry is an experimental technique to measure instantaneous velocity and temperature fluctuations in flows. The sensing wire of the probe is a thin wire. It is prone to large amplitude resonance vibrations when exposed to turbulent flow, which may cause significant errors in measurements. Therefore, minimising resonance vibrations of the wire should improve the accuracy of measurements. To this end, numerical predictions and laboratory measurements with a scaled model are presented. Currently, flow measurements are being taken to demonstrate the accuracy due to the proposed structural modifications. The method also holds promise for other problems where it is possible to manipulate the spectral distribution of natural frequencies.