Abstract: Based on the Fluent platform,a three-dimensional transient numerical simulation of the gas-liquid two-phase flow in a bubble generator with and without a static mixer was performed under inlet pressures of 0. 1 and 0. 2 MPa using the Eulerian-Eulerian two-fluid model and the Realizable k-ε turbulence model. The mesh for the model without the mixer was approximately 90 000 cells,and it increased to approximately 420 000 after adding the static mixer. The pressure-velocity coupling was handled by the SIMPLE algorithm,and the steady-state results were extracted after the residuals and monitored parameters became stable. The results show that increasing the inlet pressure significantly increases the maximum liquid velocity at the throat and enhances the flow driving force,but the pump power requirement and energy consumption also increase. The static mixer can effectively improve the uniformity of gas phase distribution in the oscillation chamber. Under an inlet pressure of 0. 1 MPa,the cross-sectional average gas holdup for the case with the mixer is close to that for the case without the mixer at 0. 2 MPa. Meanwhile,the axial pressure gradient becomes flatter,indicating that the static mixer helps reduce flow energy loss.In summary,the static mixer can improve the gas-liquid distribution and flow structure and has reference value for the energy saving and performance optimization of bubble generators.