Visualizing experimental investigation on gas-liquid replacements in a microcleat model using the reconstruction method  

作　　者：Shaojie Chen Jicheng Zhang Dawei Yin Faxin Li Jialin Lu Peiyang Zhu 

机构地区：[1]College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao,China [2]State Key Laboratory of Strata Intelligent Control and Green Mining,Shandong University of Science and Technology,Qingdao,China

出　　处：《Deep Underground Science and Engineering》2023年第3期295-303,共9页深地科学（英文）

基　　金：National Natural Science Foundation of China,Grant/Award Numbers:52074169,52174159,522741280。

摘　　要：Cleats are the main channels for fluid transport in coal reservoirs.However,the microscale flow characteristics of both gas and water phases in primary cleats have not been fully studied as yet.Accordingly,the local morphological features of the cleat were determined using image processing technology and a transparent cleat structure model was constructed by microfluidic lithography using the multiphase fluid visualization test system.Besides,the effect of microchannel tortuosity characteristics on two‐phase flow was analyzed in this study.The results are as follows:(1)The local width of the original cleat structure of coal was strongly nonhomogeneous.The cleats showed contraction and expansion in the horizontal direction and undulating characteristics in the vertical direction.(2)The transient flow velocity fluctuated due to the structural characteristics of the primary cleat.The water‐driven gas interface showed concave and convex instability during flow,whereas the gas‐driven water interface presented a relatively stable concave surface.(3)The meniscus advanced in a symmetrical pattern in the flat channel,and the flow stagnated due to the influence of undulation points in a partially curved channel.The flow would continue only when the meniscus surface bypassed the stagnation point and reached a new equilibrium position.(4)Enhanced shearing at the gas-liquid interface increased the gas‐injection pressure,which in turn increased residual liquids in wall grooves and liquid films on the wall surface.

关 键 词：dynamic contact angle flow visualization instantaneous velocity microcleat residual liquid 

分 类 号：TG6[金属学及工艺—金属切削加工及机床]