Three-dimensional Simulation Of Local Flow Field Change In Multiphase Flow Experiment Loops

Computational Fluid Dynamics is currently an important branch of fluid mechanics,which makes flow questions that have no analytical solutions with numerical solutions.The CMFD software TransAT developed by ASCOMP from Switzerland have significant advantages in tracking interface,simulating turbulence and fluid-solid coupling.Yet with limited experiment equipment and conditions,the overall flow laws are not always available.Thus numerical simulation can be a vital reference.Therefore,with TransAT simulating the flow field of multiphase experiment loop,invisible flow situation can be simulated and presented and details of the flowing process can be obtained,which would be a strong reference for multiphase flow studies.With discrete particle tracking model,local flow fields of hydrate particle flowing in a loop is simulated for the first time.The flow boundary conditions and initial conditions of particles are set;the flow process of particles in straight pipe section is calculated.Through the simulation of hydrate particles movements in circle pipe,the impact of circle flow channel on particles movements and deposition are explored.Meanwhile,this paper also uses levelset method and large-eddy simulation to calculate the gas-water two-phase flow.With the interface tracking method,this paper tracks the interface with its movement and change,as well as discusses the experiment condition's influence on flow pattern.Moreover,different turbulence models are compared and a brand new way of calculating two-phase flow using a smooth continuous function is applied to track the interface instead of traditional multiphase models.Meanwhile,this paper gives a performance evaluation on TransAT.The conclusion shows: that TransAT does a good job on fluid-solid coupling with the particle tracking model;that levelset method can precisely tracking the interface between two phase;that large-eddy simulation can give an ideal result on turbulence calculation.Yet TransAT is currently not suitable for complicated calculations and there are difficulties on its promotion.