Experiment Research Flow Characteristic Of The Porous Media Through Staggered20mm Glass Ball

The mechanism of turbulence and transition problem has always been the biggest mysteryin fluid flow. The mystery of the crack may bring a major breakthrough in Nonlinear Science.We all know that fluid flow in porous media is more complex and more difficult if you want tograsp therules. However, it’s widely used inthefield both industrial and agricultural production.So study the transition and turbulent characteristics have great significance. In this paper, thecharacteristics of the flow pattern of the porous media in the20mm cross row of glass sphereswere explored by using the PIV test system and the Tecplot post processing software. Therelevant characteristics of changes and the transition condition of flow Reynolds number areobtained.We use Tecplot software and obtain center section of the flow field, streamline andvorticity contour map of20mm fork row ball bed porous media under different Reynoldsnumbers. Figure research shows that the flow field at Re=4.7is small rate and uniformdistribution. The flow field has been changing at Re=23.3and began increase. The area of theflow velocity flow field change dramatically when at Re=128.4, at Re=128.4X100mm to120mm, in the Y area began to form between20mm to40mm quadrilateral pattern, thispattern has been stable existence to Re=1000. The size shape change with Reynolds numberslightly, reflects the general characteristics of turbulent coherent structures. At Re=23.3,according to the flow chart, the flow has changed a certain degree. The streamline and theirdistribution has change hardly between Re=217.8to Re=245.1. At Re=128.4, the X100mmto130mm, the Y form20mm to80mm conch shape pattern, this pattern present until Re=1000. The shape and size is different with the different Reynolds numbers, so the flow alsoshowsthat theexistenceofcoherent structuresanddifferentformsin flowfield.According to the analysis of velocity, fluctuating velocity and turbulence intensity in X andY direction, in the location (83.914383,115.81933) and the changing process at Re=4.7to Re=1000, X, Y direction velocity, fluctuating velocity increases with Reynolds number. At Re=128.4, X, Y direction velocity, fluctuating velocity and turbulence intensity have changed significantly. The rest of the four different location point research also shows that the coordinatepoints at (83.914383,115.81933) almost fit the same change rule. Therefore, according to theflow field, speed and fluctuation velocity change comprehensive analysis, at the Re=128.4theinside flow of porous media has been completely into turbulence under the experimentalconditions in this paper, so laminar to turbulent Reynolds number must be Re=81.7to Re=128.4,includingRe=128.4.