Experimental Study And Cfd Simulation Of Single Dropl Breakup In Taylor-Couette Flow

Liquid-liquid breakup is a common physical phenomenon in many industrial processes,which can increase the contact area of the liquid-liquid two-phase,thereby promoting the mass transfer and heat transfer between the liquid-liquid two phases.However,the breakup rules of drops in a multiphase flow field is still not very clear,and the critical breakup conditions for drops obtained in different forms of reactors are still not uniform.Therefore,this paper conducts research on the breakup process of a single liquid drop in TaylorCouette reactor to obtain the breakup conditions in this type of rotating slit reactor.The research methods in this paper mainly include experimental research and numerical simulation.In the experiment,high-speed camera technology was used to study the breakup conditions,breakup probability,and breakup time of the drops in the Taylor-Couette flow field;the two-dimensional PIV(Particle Image Velocimetry)technology was used to study the characteristics of the single-phase flow field under the conditions of drop breakup,and analyzed,and the role of viscous force and inertial force in the process of drop breakup is analyzed.For drops with an equivalent diameter of 6.0mm(±0.2mm),the experimental results show that as the rotor Reynolds number increases,the drop breakup probability increases,and the average breakup time decreases.The rotor critical Reynolds number for droplet breakup is 16328.By analyzing the flow field structure in the Taylor-Couette reactor,the turbulent kinetic energy,dissipation rate,and shear rate range of the drop breakup region under critical conditions are obtained,and the critical capillary number when the drop breakup occurs is 0.27,The critical Weber number is 4.79.In the numerical simulation,two-dimensional and three-dimensional simulation methods were used to simulate the breakup process of a single drop,and compared with the experimental results,a reasonable and accurate simulation method was obtained.And the flow field,droplet trajectory,surface area change,and critical Weber number are analyzed accordingly.The results show that the two-dimensional simulation can not truly restore the drop’s stretching and breakup process in the axial direction,while the threedimensional simulation is more accurate in describing the breakup time and deformation degree of the drop.In the process of deformation and breakup,the drop is deformed and broken by a combination of tangential shearing and axial stretching.Finally,according to the characteristics of the flow field during the movement of the drop,the U~2 of the Weber number is redefined.When the Weber number is found to be less than 3.98,the drops are not broken.When the Weber number is greater than 5.35,the drops can be broken.