In industrial pumps, Diffuser Rotating Stall (DRS) can occur within the vaned diffuser when operating at low flow rates. DRS poses a risk of vane fatigue failure due to repeated stress caused by unsteady flow. Since this phenomenon significantly limits the operational range of pumps, various methods for suppressing DRS have been investigated. However, achieving both effective suppression and maintaining high efficiency remains a challenge. In this study, the effect on DRS was investigated by combining two suppression methods: partial removal of the leading edge of the diffuser vanes and the use of tandem vanes. Experimental results showed that, compared to the use of each method individually, the combined approach more effectively suppressed DRS while maintaining the base model’s efficiency at the design flow rate. These findings demonstrate the effectiveness of combining both methods.
Takahashi et al. (2025) studied this question.