机械

以9-19型风机叶轮为例，本文对离心风机叶轮叶片进行了变减速流型优化设计，并分析对比了变减速优化流型与等减速流型。数值模拟和流场分析表明，变减速流型叶轮的作功能力、整机效率均高于等减速流型，且适应变工况的能力更优。对比等减速流型，在设计流量工况时，变减速流型的效率略高、压力提高了2.3%，而在大流量工况时，变减速流型的效率高出约2%，压力提高了3.8%。变减速叶片流道的压力梯度和速度梯度分布更均匀，在叶片中段的流动扩压度较大，而在叶片出口处的扩压度较小。变减速流型叶轮出口截面的射流-尾迹结构较弱，内部的流动整体状况更优。

Taking the 9-19 type fan impeller as an example, this paper presents a variable deceleration flow pattern optimization design for the blades of a centrifugal fan impeller and compares the performance of the optimized variable deceleration flow pattern with the constant deceleration flow pattern. Numerical simulations and flow field analyses demonstrate that the variable deceleration flow pattern impeller exhibits higher power output and overall efficiency compared to the constant deceleration flow pattern, with superior adaptability to varying operating conditions. When compared to the constant deceleration flow pattern, the variable deceleration flow pattern achieves slightly higher efficiency at the design flow rate, with a 2.3% increase in pressure, while at high flow rates, the efficiency is approximately 2% higher and pressure increases by 3.8%. The variable deceleration blade passage exhibits more uniform pressure and velocity gradients, with greater flow deceleration in the mid-section of the blades and smaller deceleration at the blade outlet. The jet-vortex structure at the outlet section of the variable deceleration flow pattern impeller is weaker, resulting in better overall internal flow conditions.