Study Of Digital Image Velocimetry For Simultaneous Flow Fileds In Two Dimensional Plane

Particle image velocimetry(PIV) is a kind of technology which now has a vigorous development. As PIV is defined by its software and hardware environment, there are many differences at its application level, furthermore there is no enough chance to apply it, so it is urgent for us to have an effective method to measure simultaneous flow fields which is required to be feasible in engineering and on the basis of PIV. The technology of digital image velocimetry for simultaneous flow fields in two dimensional plane is based on PIV theory, it's easier to make out than PIV, and also can be applied to measure velocity of large scales.The paper have a detailed research on the theory of PIV, and it discussed the theory of digital image, removing additive noise, filtering technique, reconstructing image and velocity measurement.Based on theory analysis, the author has exploited a set of software to measure simultaneous velocity vectors for flow fields in two dimensional plane. Three types of flow fields in two dimensional plane have been measured by using these system on the condition of low speed, and it obtained high quality image and velocity vector chart, it also gave out data_base of three flow fields, such as the flow field there no barrier, the field of flow around circular cylinder and the field of flow around triangle. This set of software can be used to measure simultaneous velocity vectors in two dimensional plane and is able to handle image automatically. A new method is presented which can measure the feature of simultaneous flow fields when the flow fields is illuminated with natural light, and has the higher value in the sense of scientific research and practicability.The experimental results indicated that the software which the author have exploited has the character of low price and can be easy achieved in the sense of measuring simultaneous flow fields, and it has a better reference value for resolving the difficulty of velocity measurement for simultaneous flow fields in two dimensional planeof low speed and large scale.