The Cross-Flow Fan is also known as the Cross-flow Fan, the impeller is multi-bladed and long cylindrical, and the Dc Cross Flow Blower has forward multi-wing blades. When the impeller is rotating, the air flow enters the cascade from the open part of the impeller, passes through the impeller interior, and drains into the volute from the other side of the cascade, forming the working air flow. The flow situation of Dc Cross Flow Fan high temperature airflow in the impeller is very complex, and the flow velocity field is unstable. There is also a vortex in the impeller, whose center is located near the cochlear tongue. The existence of vortex makes the output end of the impeller produce circulation flow. Outside the vortex, the Flow line in the impeller of Dc Cross flow Fan is circular.