Abstract
Using gas-liquid segmented micromixers to prepare nanoparticles that have a homogeneous particle size,controllable shape,and monodispersity advantages.Although nanoparticle aggregation within a mi-crofluid has been shown to be affected by the shear effect,the shear effect triggering conditions in gas-liquid two-phase flow is unclear and the aggregation behavior of nanoparticles under the shear effect is difficult to predict,resulting in uncontrollable physical and chemical properties of nanoparticle ag-gregates.In this study,a numerical simulation of nanoparticle aggregation in gas-liquid two-phase flow under the shear effect is performed using the CFD-DEM method.Then,the effects of total flow rate,gas-liquid two-phase flow ratio,and particle volume fraction on particle aggregation were analyzed to achieve control of particle aggregation shape and size.Meanwhile,the triggering mechanism of the shear effect and the mechanism of the shear effect on the aggregation of nanoparticles were clarified.The re-sults show that increasing the total flow rate or decreasing the gas-liquid two-phase flow rate ratio can induce the shear effect,which reduces the particle aggregation size and makes the morphology tend to be spherical.Moreover,increasing the particle volume fraction,and total flow rate or decreasing the gas-liquid two-phase flow rate ratio also increases the number of particle collisions and induce interpar-ticle adhesion.Hence,particle adhesion and the shear effect compete with each other and together affect particle aggregation.
基金项目
Shanghai Beyond Limits Manu-facturing Project()
国家自然科学基金(11502044)
国家自然科学基金(U1906233)
中央高校基本科研业务费专项(DUT22JC08)
Dalian city supports in-novation and entrepreneurship projects for high-level talents(2021RD16)
Liaoning Province's Xing Liao Talents Program(XLYC2002108)
NETL
NSTL
万方数据