Experimental design considerations for pulsed holographic particle tracking velocimetry

摘要

Abstract: This study examines some of the advantages and disadvantages of using far-field holographic recording to study velocity fields. Several important experimental design features are discussed and resolution and inherent signal-to-noise ratio problems are presented. Seeding requirements for determining velocity scales down to the Kolmogorov range are presented based on a Poisson distribution of seed particles. The source density, a measure of the seeding density, is restricted to values much less than one to achieve adequate holographic imaging. The limitations of particle motion during exposure required for adequate imaging are also assessed. The seeding density is limited by the desired measurable velocity range, according to particle tracking requirements. Experimental measurements of a velocity and vorticity field are presented, and the effects of seed density, particle motion, and tracking sequence on the velocity range are included.!11