Lsv Technology Related Theoretical Studies. Used To Measure Nanoparticles In The Fluid Velocity

The main purpose of this paper is to study to measure the velocity of the nano-particle in the nano-fluids by means of the laser speckle velocity in theory and experiment. The nano-particle is Fe₃O₄ and the fluid is water. The static experiment is done.In this paper, first I introduce some characteristics of the nano-fluids such as motion. The parallel laser is used to illuminate vertically the nano-particle producing dynamic speckle. The Laser speckle velocity is underlain by the fact that movement of a diffuse object illuminated by coherent light results in a random time variation of a speckle pattern observed in both the image plane and the diffraction field. The speckle velocity equal to the nano-particle velocity in the fresnel diffraction field is proved in theory. The speckle images are recorded by means of CCD and the speckle velocity method is cross-correlation. So if we measure the velocity of the speckle, we can know the velocity of the nano-particle.In order to do the dynamic experiment, the laser permeation is measured when the laser illuminate the nano-fluids under the different thickness and the different temperature. We know the effect of the temperature is very little and get the appropriate thickness nano-fluids to do the dynamic experiment.The main significance of this paper is to offer an experimental method to measure the velocity of the nano-particle in the nano-fluids.