Investigating scale interactions in temporal and spatial velocity signals of a Plane Wall-Jet

Measurements were conducted using 1D Hot-Wire Anemometry (HW) and 2D Low Speed Particle Image Velocimetry (LS PIV) on a plane wall-jet facility. The jet exit velocity was U_j = 31.8 ms^-1 with the jet exit Reynolds Number, Re_j = 21228. The scale decomposition of the velocity signals from both these methods was obtained using wavelet transform. The measure of interactions between the scales was determined using the Amplitude and Frequency modulation coefficients (R_AM and R_FM) as proposed by Baars et al. 2015. The coefficients were estimated assuming Taylor’s hypothesis for the HW measurements. Whereas, for the LS PIV, spatial velocity signals were considered. The trends of R_AM and R_FM obtained through both the measurement techniques were compared across all the wall normal locations. Attempts are made to explain the discrepancies between the two results and shortcomings of one measurement technique over another.