Calibration of multiple cameras for large-scale experiments using a freely moving calibration target

Abstract: Obtaining accurate experimental data from Lagrangian tracking and tomographic velocimetry requires an accurate camera calibration consistent over multiple views. Established calibration procedures are often challenging to implement when the length scale of the measurement volume exceeds that of a typical laboratory experiment. Here,...

Ψ -PIV: a novel framework to study unsteady microfluidic flows

Abstract: In microscopic particle image velocimetry (micro-PIV), correlation averaging over multiple frames is often required, leading to a loss in temporal resolution, therefore limiting the measurement accuracy for unsteady flows. Here, we present a new PIV method suitable to study steady and unsteady laminar flows between parallel plates ...

Scalar mixing in a turbulent boundary layer

We present results on the analysis of measurements on the dispersion of a contaminant in a turbulent boundary layer. The contaminant is a fluorescent dye (Rh.-B) that was introduced in a turbulent boundary layer (푅푅푒푒# = 3050) in a water channel. The velocity field was measured by means of tomographic PIV. Simultaneously, the concentration field...

Ψ-PIV: A novel framework to study unsteady microfluidic flows

In micro-PIV, reaching the optimum image density has always been difficult due to high displacement gradient, coagulation of particles at the inlet and due to particles adhering to the surface to name a few. The most widely used method is to take ensemble correlation average of multiple PIV images to extract the velocity field. However, this...

Multiple-view camera calibration for large scenes with limited spatial access at the Rotterdam Zoo

Obtaining accurate experimental data from Lagrangian tracking and tomographic velocimetry requires an accurate and consistent camera calibration over multiple views. At length-scales that span beyond the laboratory environment obtaining a camera calibration can be challenging. Combining tools developed in computer vision and non-linear camera...