Dantec Dynamics - Model 3D PIV - Volumetric Velocimetry Systems
From Fluid Mechanics
Volumetric flow field information with 2, 3 or 4 cameras. Volumetric Velocimetry (VV) also known as 3D PIV or Tomo PIV provides truly volumetric velocity data, using up to four cameras with telecentric lenses, and a thick light sheet or a scanning thick light sheet. Time-resolved VV solutions using time-resolved CMOS cameras, as well as “classical” solutions with CCD cameras are available. For low to medium seeding concentration, Particle Tracking Velocimetry (PTV) is used with two or three cameras, whereas for high seeding concentration (like PIV) a Least Squares Matching (LSM) algorithm provides 3 velocity components in a 3D volume, often described as 3D-3C (3 dimensions - 3 components).
Full shear tensor directly from the LSM data processing
The LSM is a very computationally efficient and fast processing method, providing much more information than classic cross-correlation based tomographic PIV: the full shear tensor describing scale, rotation and shear without the need to derive this data from the velocity field is inherently available.
The computational speed increase is twofold: 1) LSM is faster than cross correlation, and 2) the full shear tensor is computed in the same calculation as the velocity field. With PIV processing, the shear tensor must be computed after the velocity field.
Straightforward upgrade path from Stereo PIV to Volumetric Velocimetry
Stereo PIV systems are easily upgraded to volumetric Particle Tracking Velocimetry (PTV) by adding telecentric camera lenses and a software add-on. Adding a 3rd camera, tomographic PTV in medium seeded flows is possible, and adding a 4th camera, Volumetric Velocimetry using a Least Squares Matching algorithm is possible.
True 3D data visualisation
With volumetric velocity information available, visualising and understanding the data is a challenge. DynamicStudio supports true 3D visualisation using speical shutter glasses and a monitor capable of 3D viewing. This greatly helps understanding the spatial flow structures.
Dantec Dynamics has many years of experience in helping customers with special system requirements to fit a specific application. Our team of engineers is ready to help you design a measurement system that meets your specific needs so you can reach your goals efficiently and successfully.