High Resolution Shadow Imaging
High resolution imaging and special backlight illumination are the key components of the ParticleMaster Shadow system. As opposed to laser diffraction or interferometric methods shadowgraphy does not require transparent and spherical particles and, therefore, is a quite universal technique for comprehensive particle characterization.The ParticleMaster software package automatically identifies valid particles in an image series and calculates all particle properties with outstanding processing speed incl. statistical information in real-time.
Shadowgraphy can well be combined with other flow imaging methods like PIV or thermometry for use in multiphase flows.
Tomographic Shadow Imaging
Our ParticleMaster 3D Shadow systems are based on tomographic shadow imaging. Using multiple shadow projections the tomographic reconstruction module in DaVis calculates the position and shape of particles, bubbles and droplets in 3D space. With time-resolved recordings particle trajectories with velocity and acceleration data are measured.
Time-resolved tomographic shadow imaging was successfully applied in bubbly flows for 3D flow imaging of both phases.
- Simultaneous size, position and shape
- Particle number density (corrected for different size classes)
- Particle velocity derived from double frame exposures
- Velocity - size correlations, histograms, scatterplots
- Mass flux
- Visualization of ligaments, spray break-up and atomization
