Abstract：In order to study and design a centrifugal aerator with high effciency aeration, uses NX software to establish three dimensional model, and uses FLUENT19.2 software to carry out the VOF numerical simulation of multiphase flow in the flow components of the centrifugal aeration machine. The standard k-ε turbulence calculation model and the SIMPLE algorithm were selected, and the concept of the relative area ratio of the mixing disc of the aerator ð which represents the ratio of the mixing disc area of the centrifugal aerator to its outlet area is proposed. The calculation results show that: The aeration performance of the centrifugal aerator with the discharge pipe is significantly improved compared with that without discharge pipe arrangement, and the air content in the mixing disc is increased by 47%, which verifies the necessity of the discharge pipe arrangement. The effect of the relative area ratio of the mixing disc of the aerator on the aeration performance is further studied. The gas volume fraction in the mixing disc of the aerator and the pressure difference on the surface of the runner are used as indicators to measure the performance of the aerator. The results show that the outlet flow rate of the centrifugal aerator firstly increases and then decreases with the relative area ratio of the mixing plate( ð), and it reached its maximum when the ratio is 8.377, with the outlet flow rate reaching 16.617 kg/s. The results can provide guidance for structural optimization design of a centrifugal aerator and the improvement of oxygenation performance.
