Shake-the-Boxis the most advanced 3D Lagrangian Particle Tracking Velocimetry (PTV) method for densely seeded flows at highest spatial resolution. Compared to the voxel-basedTomo-PIVapproachShake-the-Boxis 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-Boxachieves a higher reconstruction accuracy at much faster processing speed compared with itsTR-Tomo-PIVcounterpart. Beside differentDaVissoftware packagesFlowMastersystems forTR-Tomo-PIVandShake-the-Boxare using the same hardware.
time-resolved PTV for 4D flow analysis at high seeding densities
award-winning particle reconstruction and tracking algorithm: 4th International PIV Challenge
unsurpassed precision for velocity and acceleration of particle tracks
TheMiniShakeris an aligned multi-sensor system in a compact housing for quick and easy volumetric flow measurements. Integrated into LaVision’s DaVis software,Shake-the-Box(4D-PTV) as well asTomographic PIVflow fields are readily obtained. The power supply and data transfer of the system both use USB-3 interfaces largely simplifying installation and operation.
TheMiniShakeris available in three models and with adaptable lenses for diverse measurement tasks. In combination with LaVision’s cost-effectiveLED-Flashlightit is ideal for measurements of water applications. Mounted to a robotic arm and combined withHelium-filled Soap Bubbleseeding, the flexible system is most appropriate for large-scale flow analysis of low- to mid-speed wind tunnel and convective air flow applications.
Flow field of a large thermal air plume calculated withShake-the-Boxapplying Helium-filled soap bubble seeding, DLR 哥廷根友情提供
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’sHFSB Seeding Generatorcan 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 60 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.
Time-resolved 3D flow fields have been successfully measured behind a serial car in a large wind tunnel at Volkswagen. The field-of-view was 2 m x 1.6 m with a light sheet thickness of 0.2 m. The air flow was seeded with 0.3 mm in diameter Helium-filled soap bubbles applying seeding rates of more than 2 million bubbles per second operating 60 seeding nozzles.
Four high-speed cameras recorded the 3D wake flow at wind speeds of 60 km/h and 120 km/h, respectively. A high-speed laser was used for illumination. LaVision’sShake-the-Boxtime-resolved 3D-PTV technique was applied to calculate the time-resolved 3D flow fields.