Study On Influence Of Storage Flow Pattern On Side Pressure Of Silo Based On Image Processing

During the unloading process,it is widely accepted that the dynamic pressure is higher than static pressure,for which the mechanism is not clear.Therefore,different corrective methods have been adopted in many countries,including China,for the silo design regulations to consider dynamic pressure on basis of static pressure.Studies of increasing mechanism and the calculations of dynamic pressure have always been the major basic research topics in silo industry,which are yet to be solved.This paper has experimented on the increasing mechanism of silo dynamic pressure with the assists of a National Natural Science Foundation of China project: <Study on Dynamic Overpressure Mechanism of Silo Based on Energy Conversion of Loading and Unloading Process(51578216)>.3 major activities have been performed and summarized as below:1)To better study the material flow during unloading process,a Plexiglas silo has been used.Earth pressure sensors have been marked and placed on the inner wall of the silo,monitoring the values of inner static side pressure and dynamic side pressure on silo walls.Analysis has been performed to evaluate relations among static pressure,dynamic pressure and deep silo specification.Over-pressure coefficient of each measuring point has been calculated to compare the results of identical measuring points,in order to obtain the location of maximum over-pressure coefficient.2)Filming the material flow with high speed cameras and processing the obtained visual materials with digital image processing function of MATLAB.A new method of material flow analysis with assistance of digital image processing has been proposed.Such method is still in primitive stage.This case study has shown a new way of thinking of bulk mechanics.3)Considering the energy conversions between silo walls and materials during unloading process,a study on the interactions between such two types of energy has been performed to analyze the increasing mechanism of dynamic pressure.Strain energy from silo walls has been released during unloading,which disturbs the energy balance inside the silo.Material pressure on silo walls shall be considered as passive pressure,which can be used to explain the increasing mechanism of dynamic pressure.Formulas and theoretical analysis can be established on basis of energy principles.