层析粒子成像测速

This paper describes the principles of a
novel 3D PIV system based on the illumination,
recording and reconstruction of tracer particles within
a 3D measurement volume. The technique makes use
of several simultaneous views of the illuminated particles
and their 3D reconstruction as a light intensity
distribution by means of optical tomography. The
technique is therefore referred to as tomographic
particle image velocimetry (tomographic-PIV). The
reconstruction is performed with the MART algorithm,
yielding a 3D array of light intensity discretized
over voxels. The reconstructed tomogram pair is then
analyzed by means of 3D cross-correlation with an
iterative multigrid volume deformation technique,
returning the three-component velocity vector distribution
over the measurement volume. The principles
and details of the tomographic algorithm are discussed
and a parametric study is carried out by means of a
computer-simulated tomographic-PIV procedure. The
study focuses on the accuracy of the light intensity field
reconstruction process. The simulation also identifies
the most important parameters governing the experimental
method and the tomographic algorithm
parameters, showing their effect on the reconstruction
accuracy. A computer simulated experiment of a 3D
particle motion field describing a vortex ring demonstrates
the capability and potential of the proposed
system with four cameras. The capability of the technique
in real experimental conditions is assessed with
the measurement of the turbulent flow in the near
wake of a circular cylinder at Reynolds 2,700. 德国LaVision PIV/PLIF粒子成像测速场仪 体视层析粒子成像测速系统(Tomo-PIV) Imager pro X PIV相机