面向粒子图像测速仪的分参数校准方法OA北大核心CSTPCD

The calibration methods of particle displacement and cross-frame time during particle image velocimetry(PIV)measurement are studied.The geometric size standard of disc is designed for camera calibration,the proportional relationship between the image obtained by camera and the object is determined,and the particle displacement calibration is realized by comparing with the ruler under the same experimental condition.A traceable timer is used to calibrate the time interval of PIV synchronizer pulse signals at different speed points.The cross-frame time correction coefficient is the ratio of the actual value to the initial value.As the result the PIV calibration coefficient is determined by the particle displacement correction coefficient and the cross-frame time correction coefficient.The uncertainty of PIV calibration results based on the sub-parameter method is evaluated.The results indicate that:at the theoretical speed point of 100 m/s,the maximum relative error is 0.08％,and the uncertainty of the relative error is 0.01％.