<p>To evaluate the mixing performance of the novel mixer, a numerical simulation method was employed to investigate the internal flow field characteristics and phase volume fraction distribution. The results indicate that the maximum pressure occurs at the middle section of the central tube, and the pressure difference between this section and the outlet tube leads to the highest flow velocity within the right-hand rotating channel of the central tube. The gas emanating from the right-hand rotating channels (Layers 4 to 11) reaches the mixer’s inner wall. Under the combined influence of this gas and the tangentially injected gas from the side inlet, the entire flow inside the mixer assumes a clockwise pattern. Guided by the upper and lower curved plates on the inner wall, the side-injected gas drives the surrounding flow along the inner wall toward both ends of the mixer. After impinging on the end caps, the flow reverses direction and moves along the outer wall of the central tube toward the central outlet tube, where it is discharged. Ultimately, a three-dimensional flow pattern is established: horizontally, the gas flows clockwise within each layer, while vertically, it exhibits a counter-rotating structure with counterclockwise motion in the upper half and clockwise motion in the lower half. This flow pattern effectively enhances gas mixing. This conclusion is supported by the observed uniform oxygen concentration distribution across different layers, with minimal variation. Furthermore, the relative error between the simulated and theoretical oxygen content at the outlet is only 3.65%, which further validates the high mixing efficiency of the novel mixer design.</p>