Numerical Simulation Study On The Influence Of Variant Blade On Hydraulic Performance Of Axial-flow Pump

Traditional axial-flow pump angle adjustment is achieved by rotating the rigid blades of the impeller to change the blade angle as a whole, thereby regulating the pump’s operating conditions. However, because the flow state of the water differs between the hub and rim of the impeller, this method of angle adjustment is neither flexible nor accurate in adjusting the pump’s performance under different operating conditions. This makes it difficult to meet the demand for efficient operation under complex conditions. This study proposes a flexible blade variant scheme, where the blades actively twist to finely adjust the flow state of the water from the hub to the rim of the impeller. This reduces hydraulic losses and ensures optimal performance of the pump under various operating conditions. To explore the impact of variable blades on the hydraulic performance of axial-flow pumps, five sets of typical shapes of variable blades at different angles were selected. The hydraulic performance of the pump with these selected blade shapes was studied using numerical simulation methods. The results show that when the pump operates away from the design conditions, the variable blades can actively deform to change the internal flow pattern of the impeller, increasing efficiency by 6.2% and 22.6% at $0.8 Q$ and $1.2 Q$ conditions, respectively. When the pump operates under low flow conditions, the blades should twist clockwise, and under high flow conditions, the opposite. Compared to the rigid blades of traditional axial-flow pumps, variable blades can significantly enhance the hydraulic performance of the pump, expand the high-efficiency operating range, and provide precise adjustment capabilities, offering a new approach for improving the hydraulic performance of axial-flow pumps.