Abstract：In order to deeply compare the influence of different placement angles of agitators on the hydraulic characteristics of sewage treatment tanks, the hydraulic characteristics of agitator under different placement angles based on Fluent are simulated, tand the optimal working conditions for agitator are obtained. The standard k-ε turbulence model and SIMPLEC algorithm were used to simulate the corresponding velocity distribution and the velocity components in the plane where the center of the agitator is located are compared. The results show that the average flow velocity in the treatment tank is higher and the power consumption of agitator is smaller when the placement angle is -15°. By analyzing the velocity component of the central cross-section of the placement position of the agitator under five working conditions, it is found that the water passing through the agitator develops in a spiral direction towards the direction of flow direction. In Cartesian coordinate system, the velocity components in three directions are different. When the placement angle is -15°, the velocity component of fluid on the y and z axes is larger, and does not conflict with the wall. Therefore, in practical application, by appropriately changing the placement angle of the agitator can be effectively improve the circulation flow and the mixing effect of the agitator can be optimized. The research results can provide reference for practical engineering of submersible.
