Shake-the-Box is the most advanced 3D Lagrangian Particle Tracking Velocimetry (PTV) method for densely seeded flows at highest spatial resolution. Compared to the voxel-based Tomo-PIV approach Shake-the-Box is a purely particle-based technique using an Iterative Particle Reconstruction (IPR) technique in combination with an advanced 4D-PTV algorithm using the time-information for track reconstruction. Shake-the-Box achieves a higher reconstruction accuracy at much faster processing speed compared with its TR-Tomo-PIV counterpart.
Beside different DaVis software packages FlowMaster systems for TR-Tomo-PIV and Shake-the-Box are using the same hardware.
Air seeding with µm-particles is not suitable for large scale PIV/PTV experiments due to their limited scattering power. Neutrally buoyant Helium-filled Soap Bubbles (HFSB) with a diameter of 0.3 mm and a response time less than 15 µs scatter 10000x more light than µm-particles and, therefore, are suitable for large scale PIV/PTV experiments in the lower subsonic regime.
LaVision’s HFSB Seeding Generator can deliver 0.3 mm mono-sized bubbles at a production rate of 40000 bubbles per second and per nozzle and can operate simultaneously up to 50 nozzles in parallel. The typical life time of the Helium-filled soap bubbles is a few minutes. Furthermore, the increased scattering intensity allows to switch from laser to LED illumination, greatly reducing the cost of the light source.