We have developed a parallel algorithm for microdigital-holographic particle-tracking velocimetry. The algorithm is used in (1) numerical reconstruction of a particle image computer using a digital hologram, and (2) searching for particles. The numerical reconstruction from the digital hologram makes use of the Fresnel diffraction equation and the FFT (fast Fourier transform), whereas the particle search algorithm looks for local maximum graduation in a reconstruction field represented by a 3D matrix. To achieve high performance computing for both calculations (reconstruction and particle search), two memory partitions are allocated to the 3D matrix. In this matrix, the reconstruction part consists of horizontally placed 2D memory partitions on the x–y plane for the FFT, whereas, the particle search part consists of vertically placed 2D memory partitions set along the z axes. Consequently, the scalability can be obtained for the proportion of processor elements, where the benchmarks are carried out for parallel computation by a SGI Altix machine.

We have designed a special purpose computer system for visualizing fluid flow using digital holographic particle tracking velocimetry (DHPTV). This computer contains an Field Programmble Gate Array (FPGA) chip in which a pipeline for calculating the intensity of an object from a hologram by fast Fourier transform is installed. This system can produce 100 reconstructed images from a 1024×1024-grid hologram in 3.3 sec. It is expected that this system will contribute to fluid flow analysis.

An investigation of MHD effects on a Flibe (Li2BeF4) simulant fluid has been conducted under the US-Japan JUPITER-II collaboration program using “FLIHY” pipe flow facility at UCLA. The present paper reports a development of unique experimental techniques using aqueous solution of potassium hydroxide as a Flibe simulant. In order to apply a particle image velocimetry (PIV) technique for magnetic field condition, special optical devices were developed. The PIV measurements of MHD turbulent pipe flow at Re = 5300 were performed, and modification of the mean flow velocity as well as turbulence suppression was observed. A flat velocity profile in the pipe center and a steep velocity gradient in the near-wall region at Ha = 20 exhibits typical characteristics of Hartmann flow.