Blade profiles, blade numbers, cord of the blade, and the straight line extension of the trailing edge were simulated numerically for the return channel blades in an attempt to avoid flow separation.

• 采用修改回流器叶型、增加叶片数目、增加叶片长度、修改叶片尾部型线为直线等方法消除了回流器叶片的分离与回流。