Spatial filtering velocimetry(SFV)has the advantages of simple structure,good stability,and wide applications.However,the traditional linear CCD-based SFV method requires an accurate angle between the direction of lin...Spatial filtering velocimetry(SFV)has the advantages of simple structure,good stability,and wide applications.However,the traditional linear CCD-based SFV method requires an accurate angle between the direction of linear CCD and the direction of moving object,so it is not suitable for measuring a complex flow field or two-dimensional speed in a granular media.In this paper,a new extension of spatial filtering method(SFM)based on high speed array CCD camera is proposed as simple and effective technique for measuring two-dimensional speed field of granular media.In particular,we analyzed the resolution and range of array CCD-based SFV so that the reader can clarify the application scene of this method.This method has a particular advantage for using orthogonal measurement to avoid the angle measurement,which were problematic when using linear CCD to measure the movement.Finally,the end-wall effects of the granular flow in rotating drum is studied with different experimental conditions by using this improved technique.展开更多
Particle tracking velocimetry(PTV)is one of the most commonly applied granular flow velocity measurement methods.However,traditional PTV methods may have issues such as high mismatching rates and a narrow measurement ...Particle tracking velocimetry(PTV)is one of the most commonly applied granular flow velocity measurement methods.However,traditional PTV methods may have issues such as high mismatching rates and a narrow measurement range when measuring granular flows with large bulk density and high-speed contrast.In this study,a novel PTV method is introduced to solve these problems using an optical flow matching algorithm with two further processing steps.The first step involves displacement correction,which is used to solve the mismatching problem in the case of high stacking density.The other step is trajectory splicing,which is used to solve the problem of a measurement range reduction in the case of high-speed contrast The hopper flow experimental results demonstrate superior performance of this proposed method in controlling the number of mismatched particles and better measuring efficiency in comparison with the traditional PTV method.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11902190)the Construction Project of Shanghai Key Laboratory of Molecular Imaging(Grant No.18DZ2260400)the Fund from the Shanghai Municipal Education Commission,China(Class II Plateau Disciplinary Construction Program of Medical Technology of SUMHS,2018-2020).
文摘Spatial filtering velocimetry(SFV)has the advantages of simple structure,good stability,and wide applications.However,the traditional linear CCD-based SFV method requires an accurate angle between the direction of linear CCD and the direction of moving object,so it is not suitable for measuring a complex flow field or two-dimensional speed in a granular media.In this paper,a new extension of spatial filtering method(SFM)based on high speed array CCD camera is proposed as simple and effective technique for measuring two-dimensional speed field of granular media.In particular,we analyzed the resolution and range of array CCD-based SFV so that the reader can clarify the application scene of this method.This method has a particular advantage for using orthogonal measurement to avoid the angle measurement,which were problematic when using linear CCD to measure the movement.Finally,the end-wall effects of the granular flow in rotating drum is studied with different experimental conditions by using this improved technique.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11572201 and 91634202)
文摘Particle tracking velocimetry(PTV)is one of the most commonly applied granular flow velocity measurement methods.However,traditional PTV methods may have issues such as high mismatching rates and a narrow measurement range when measuring granular flows with large bulk density and high-speed contrast.In this study,a novel PTV method is introduced to solve these problems using an optical flow matching algorithm with two further processing steps.The first step involves displacement correction,which is used to solve the mismatching problem in the case of high stacking density.The other step is trajectory splicing,which is used to solve the problem of a measurement range reduction in the case of high-speed contrast The hopper flow experimental results demonstrate superior performance of this proposed method in controlling the number of mismatched particles and better measuring efficiency in comparison with the traditional PTV method.
