Experimental Study of Flow Feature in a Spiral Casing of Turbo Fan

In order to understand the flow feature in the inside of turbo fan, the flow pattern, and the velocity and pressure distributions were investigated by use of the tuft grid visualization method and five holes yaw-meter. The experiments were performed at three typical operating conditions (maximum efficiency discharge case, smaller and lager discharge cases). As a result of experiments, the rotating flow which has an axis to the direction of flow was observed in the spiral casing and it was found that the central position of rotating flow depended on the flow rate. In the case of maximum efficiency, it was found that the static pressure distribution was uniform regardless of the circumference angle among both parallel walls of the spiral casing. It was examined about the fluid outlet angle and the slip factor.