The Euler-Euler multi-fluid model has been widely used to simulate numerically the separation performance of oil-water mixture inside the T junction

while no study has been conducted on the oil droplet size distribution and its influence on separation performance. The CFD-PBM numerical simulation of oil-water mixture flow inside a specific T junction was carried out

and experiments were conducted in laboratory to verify the accuracy of the simulation results. It is indicated that the oil droplet size in the T junction appears a gradually increasing trend along the flow direction. With the increase of oil droplet size

the oil-water separation efficiency can be effectively promoted. On the contrary

the smaller oil droplet size leads to the difficulty of oil-water separation inside the T junction

and the fraction of phase distribution is nearly identical to the split ratio. The influence degree of operation conditions such as split ratio and Reynolds number on the separation efficiency is tightly related to the oil droplet size. Appropriate operating conditions should be selected carefully to achieve high separation efficiency for the T junction.