Abstract: A new method of 2D blade profile design on a centrifugal impeller was proposed to improve the aerodynamic performance of the impeller. The blade profile was designed through full three-dimensional numerical simulation by giving channel average relative velocity distribution along the radius，without changing the profiles of its hub and shroud. The computational results of isolated impeller show that the performance of the new impeller obviously increases in most conditions. Efficiency and pressure rise increase by 12% and 8.9%，respectively，at design point. At the same time，the low-velocity zones are both greatly reduced and the static pressure is uniformly distributed，too. The computational results for the whole fan with the original volute show that the efficiency increases by more than 10% at design point，and the backflow in the outlet section of the volute is eliminated. However，the pressure rise amount decreases in high flow conditions.

Key words: Centrifugal impeller；2D blade；Blade design；Numerical simulation

摘要： 为改善优化离心叶轮的气动性能，提出离心叶轮二元叶片型线的一种优化设计方法，即通过给定流道平均相对速度沿半径的分布规律，在叶轮轮盘轮盖线不变的前提下，设计出一类叶片型线，并利用全三维数值模拟计算得到最佳性能的叶轮。孤立叶轮的计算表明，大部分工况的性能均明显优于原始叶轮，在设计点处效率提高12%，压升提高8.9%，流道中低速区的面积大大减小，静压场分布更加均匀。最佳叶轮配上原始蜗壳进行整机计算，结果表明，设计点效率提高10%以上，且消除了蜗壳出口段的倒流现象，但在大流量工况下压升量有所下降。

关键词: 离心叶轮；二元叶片；叶片设计；数值计算