3D CFD-PBM Coupled Simulations Of Microbubble Swarms Dynamics Rising In Shear-thinning Fluids

Shear-thinning fluid microbubble group is widely used in the chemical field of gasliquid two-phase system,such as bubble column,bio fermentation,Fischer Tropsch synthesis etc..Microbubble group has a larger surface area and it can transmit heat and mass efficiently.Therefore,deep study to this system can better meet the needs of industry.It is necessary to study it to meet the needs of the industrial reactor.Based on the k-? model,this paper intensively inspect rheological properties of non-Newtonian fluid,using CFD-PBM to study the rising behavior of microbubble group in shear-thinning fluids.The main contents include:By studying 3D CFD-PBM coupled simulation column of microbubble swarms dynamics rising in shearing-thinning fluids,inspecting the effects of superficial gas velocity,liquid height,gas distributor size and different concentrations of polyacrylamide(PAM)on gas holdup of flat rectangular drum bubble column,Sauter diameter,turbulent kinetic energy and the liquid flow respectively in radial distribution trend.The simulation results showed that the gas holdup?Sauter diameter?turbulent kinetic energy?liquid velocity increased with the increase of superficial gas velocity;the gas holdup?Sauter diameter?turbulent kinetic energy?liquid velocity increases with the increase of liquid height,but when the liquid level is higher than half of the whole column,the liquid level didn't influence the above;the gas holdup,Sauter diameter,turbulent kinetic energy,liquid velocity increased with the increase of the entrance size of the liquid gas distributor.The effect of sparger on the distribution of the total gas holdup was primarily due to its effect on small bubble gas holdup.The gas holdup,Sauter diameter,turbulent kinetic energy,liquid velocity increased with the increase of liquid flow of non-Newtonian fluid concentrations of PAM.