Research Of MicroPIV Technique In Flow Field Measurement

Nowadays Micro Particle Image Velocimetry is the most popular method of full flow field measurement .In this article, we mainly study the phenomenon in micro-scale flow and design an image analyse program.The calculation formula of MicroPIV technique is the original definition of velocity: V=[S(t2)-S(tl)]/(t2-tl).On the two neighboring frame of images , we search for the two small areas which have the largest correlation .By dividing their distance by their shooting interval, we got the average velocity of this small area in this interval, and then got the velocity of full flow. The main calculation in the particle image matching algorithm is cross-correlation arithmetic. We use Fast Fourier Transform arithmetic to calculate two seriate images. This article discusses the basic principle of the cross-correlation arithmetic in detail, discuss each stage of its produce and development and also discuss the thinking, the merit and the defect of each algorithm. Based on these discusses, we confirm our algorithm and realize it in programming with C++.We describe the international development and research state of MicroPIV technique, and discuss research of micro-scale flow technique and affected factors. We investigate the whole process and technique details of MicroPIV, such as the micro scale flow mode making technique, and optimum velocity according to the existing test condition, and selecting of trace particle, the software interface of the image acquisition, the software interface, analysis of the specification parameters of the MicroPIV technique, and the selection of the key experiment parameters.By cooperating with a company and Tsinghua university, we can use advanced instrument to measure our own made micro-scale flow models. We got right data results and protract them in frank flow field figure graph. According tothe results, we give the reasonable explanation in fluid mechanics. By compared with the result of the other's expressed articles, it is proved that the practicability and feasibility of our own MicroPIV technique.It shows that the MicroPIV software composing with the image acquisition, image processing, image matching, plotting test result in field has got a satisfactory result. It has active meaning in the spread and handle of MicroPIV technique.