本文用加大叶片进出口安装角及增多叶片数,并用三元流动理论计算流场的方法对叶型进行了有效的改进,从而使高效的工况范围扩大并提高了大流量时的压头。从给出的三个流面的叶片表面速度分布可看出:改型后叶轮具有较好的气动性能及较大的作功能力。而经实验验证表明理论分析与实验结果基本一致。本文提供的实例说明用三元流理论与工程设计、实验相结合来设计和改型风机是一个切实有效的方法。 In this paper, increasing the blade installation angle and increase the number of blades, and the flow field calculated using the three-way flow method for the effective improvement of the leaf type, so that the expansion of efficient operating conditions and improve the flow of pressure head . From the surface velocities distributions of the three flow surfaces, we can see that the modified impeller has better aerodynamic performance and greater work ability. The experimental verification shows that the theoretical analysis and experimental results are basically the same. The examples provided in this paper show that it is an effective and effective method to design and modify the fan by combining the theory of ternary flow with engineering design and experiment.