The Study Of Digital Particle Image Velocimetry System And Its Application Of Model Test Of The Power Station Intake Runner

With the continuously developments of laser technology, computer science, digital particle image velocimetry technique and imagery technique, velocimetry technique of whole field has been rapidly developed in recent decades. DPIV (digital particle image velocimetry) is a new branch of PIV and a non-intrusive, instantaneous and whole-field flow survey technique, which was developed on the base of flow visualization through the digital image technique. It gets the tracer particle image of flow using digitized camera and doesn't need optics pre-process, it obtains velocity vector by dealing two successive digital image. With simple hardware equipment, it is real-time and adopts cross-correlation analysis and resolves obscure problem of speeddirection which frequently appears on tradition PIV. DPIV not only has high precision and resolution of spot measurement technique, but also gains overall structure and transient image of flat flow visualization.In physical model experiment of intake runner of generating station, for the safe operation of water pump, qualitative and quantitative measurement of runner surface flow field is one of the most important evidence which judges whether runner design is reasonable. Because traditional velocimetry technique can not meet the request of instant flow regime.Based on particular holding the principle and algorithms of DPIV, using Chinese Windows as working platform, this paper exploits independently DPIV system software using software of Visual Basic 6.0. The DPIV system has some characteristics as blow: only needing simply optical source device (adopting natural light and filament lamp) , using CCD digital camera, needing no wet processing, directly recording particle imagine; it has big memory capacity , simple operation and lower cost ; it rapidly stores date.Aiming at transient change characteristics of flat flow field of generating station intake runner, the flow field measurement ofphysical model experiment of intake runner of Fujian Kemen generating station used this system and obtained satisfied results of flow field measurement. Moreover, this system analysed its measurement error and accuracy and supplied a basis of optimum design of generating station intake runner.The DPIV velocimetry system of this paper supplies is a important tool for flow field of hydraulic physical model experiment and has high academic merit and utility meaning.