Augmenting PIV Temporal Resolution via Semi-Lagrangian Estimation of Velocity Fluctuations

This study introduces a convective velocity estimation method based on space-time correlations to enhance the temporal resolution of turbulent flow measurements using semi-Lagrangian techniques. The approach is evaluated using DNS data of a turbulent plane jet at Re=10,000$$Re = 10{,}000$$. Comparison between correlation-based convective velocity Uc$$U_c$$ and mean axial velocity Um$$U_m$$ reveals significant differences, with Uc$$U_c$$ generally lower near the jet centreline and higher towards lateral edges. Spectral analysis demonstrates that Uc$$U_c$$ based advection yields improved predictions of the turbulence spectrum compared to Um$$U_m$$. Future work will explore scale-dependent convective velocities and their impact on reconstructed frequency spectra.