As a principal reason for the deterioration of separation accuracy, the bypass effect in hydrocyclones has received widely concerned. This paper presents a numerical study about the effect of flat bottom structure width on the bypass effect with the respect of flow field characteristics, separation efficiency, and particle spatial distribution with a verified TFM model. Numerical results demonstrate that wide flat bottom structure increases the cut size and reduces the fine particles misplaced in the underflow. However, the excessive flat bottom structure width increases coarse particles misplaced in the overflow causing by the superior turbulence intensity and the entrapment of the internal swirling flow. A wide flat bottom structure width reduces the turbulence dissipation rate, while the split ratio first decreases and then increases, indicating that the bypass effect is controlled by the turbulence dissipation and does not comply with the trend of the split ratio.

作为分离精度下降的主要原因，水力旋流器中的旁通效应受到广泛关注。本文利用经过验证的 TFM 模型，从流场特性、分离效率和颗粒空间分布等方面对平底结构宽度对旁路效应的影响进行了数值研究。数值结果表明，宽平底结构增加了切割尺寸并减少了在底流中错位的细颗粒。然而，过大的平底结构宽度增加了由于优越的湍流强度和内部涡流的截留而导致的溢流中错位的粗颗粒。较宽的平底结构宽度降低了湍流耗散率，而分流比先减小后增大，