Wavelet Multi-Resolution Analysis on pressure fluctuation signals in pipe flow

Particle image velocimetry (PIV), a whole-field, non-invasive velocity measurement technique was performed to obtain a full-field quantitative description of a three-dimensional pipe flow. Steady-state and transient flows of fluid PIV is produced by instantaneous velocity maps of seeded particles. Traditional PIV approaches such as digital auto-correlation methods and the optical processing techniques can hardly help us capture the small time and length scales in fast-varying flows field with fine spatial structure and even harder to see the temporal-spatial evolution. It is necessary to use some new methods to show us transient and detailed information of both the fluid and the structure during rapid fluid-structure interactions or the energy transfer process among the different scales in transition and turbulence. The 2-D Multi-resolution analysis of wavelet technique was applied to analyze the PIV data to reveal a good understanding of the multi-scale vortice structures in the pipe flow. The instantaneous 3-D velocity fields were decomposed into large- and small-scale velocity fields. We also address the derivation of wavelet based multiresolution methods for velocity field reconstruction which can help us remove noise and extract useful information in which we are interested.

Wavelet Multi-Resolution Analysis on pressure fluctuation signals in pipe flow Conference Paper