Tomographic 3D-PIV and Applications

Direct calculation of depth of correlation and weighting function in ?PIV from experimental particle images

Micro-PIV (?PIV) uses volume-illumination and imaging of fluorescent tracer particles through a single microscope objective. Displacement fields measured by image correlation depend on all imaged particles, including defocused particles. The measured in-plane displacement is a weighted average of the true displacement with a weighting function W...

Time-resolved image analysis for turbulent flows

Classical Particle Image Velocimetry (PIV) uses two representations of the particle image distribution to determine the displacement of the particle image pattern by spatial cross-correlation. The accuracy and the robustness are however limited by the fact that only two representations at t and t +?t are present. Thus, only a first order...

Time-resolved image analysis for turbulent flows

Classical Particle Image Velocimetry (PIV) uses two representations of the particle image distribution to determine the displacement of the particle image pattern by spatial cross-correlation. The accuracy and the robustness are however limited by the fact that only two representations at t and t +?t are present. Thus, only a first order...

On the universality of PIV uncertainty quantification by image matching

The topic of uncertainty quantification in particle image velocimetry (PIV) is recognized as very relevant in the experimental fluid mechanics community, especially when dealing with turbulent flows, where PIV plays a prime role as diagnostic tool. The issue is particularly important when PIV is used to assess the validity of results obtained...

Lagrangian and Eulerian views into a turbulent boundary layer flow using time-resolved tomographic PIV

‘Shake The Box’: A highly efficient and accurate Tomographic Particle Tracking Velocimetry (TOMO-PTV) method using prediction of particle positions

A novel approach to the evaluation of time resolved particle-based tomographic data is introduced. By seizing the time information contained in such datasets, a very fast and accurate tracking of nearly all particles within the measurement domain is achieved at seeding densities comparable to (and probably above) the thresholds for tomographic...

On the universality of PIV uncertainty quantification by image matching

The topic of uncertainty quantification in particle image velocimetry (PIV) is recognized as very relevant in the experimental fluid mechanics community, especially when dealing with turbulent flows, where PIV plays a prime role as diagnostic tool. The issue is particularly important when PIV is used to assess the validity of results obtained...

Direct calculation of depth of correlation and weighting function in ?PIV from experimental particle images

Micro-PIV (?PIV) uses volume-illumination and imaging of fluorescent tracer particles through a single microscope objective. Displacement fields measured by image correlation depend on all imaged particles, including defocused particles. The measured in-plane displacement is a weighted average of the true displacement with a weighting function W...

A super-resolution approach for uncertainty estimation of PIV measurements

A super-resolution approach is proposed for the a posteriori uncertainty estimation of PIV measurements. The measured velocity field is employed to determine the displacement of individual particle images. A disparity set is built from the residual distance between paired particle images of successive recordings. Within each interrogation window...

Eulerian and Lagrangian views of a turbulent boundary layer flow using time-resolved tomographic PIV

Coherent structures and their time evolution in the logarithmic region of a turbulent boundary layer investigated by means of 3D space–time correlations and time-dependent conditional averaging techniques are the focuses of the present paper. Experiments have been performed in the water tunnel at TU Delft measuring the particle motion within a...

Multi-frame pyramid correlation for time-resolved PIV

A novel technique is introduced to increase the precision and robustness of time-resolved particle image velocimetry (TR-PIV) measurements. The innovative element of the technique is the linear combination of the correlation signal computed at different separation time intervals. The domain of the correlation signal resulting from different...

Time resolved PIV and flow visualization of 3D sheet cavitation