Noise Mitigation and Post Processing Strategies for Hot-Wire Anemometry Signals Through Wind Tunnel Assessment

The article presents simplified methodologies for evaluating the turbulence intensity (TI) of a time-lapsed flow signal acquired through a single-channel hot-wire anemometry (HWA). Apart from the classical method, the TI is also calculated through the root mean square (RMS) component of fluctuating voltage using a well-calibrated HWA. Using the proposed methodologies, the TI of a subsonic wind tunnel has been carried out. The TI measured from fluctuating voltage component is found to be relatively high, mainly due to noise imposition. In order to reduce the noise mitigation, the RMS share of non-flow signal (NFS) is evaluated and then subtracted from the flow-signal (FS). Upon execution, a reduction in TI is observed. Due to the non-discretization of raw signal into NFS and FS, a pre-spectral analysis is performed through to identify the influential frequency. Thereupon, a systematic low pass and high pass filter is applied that retrieves the required flow signatures