A Numerical Study of the 3-Dimensional Turbulent Flow Past a Bladeless Fan

A bladeless fan is designed without any observable impeller, and it is started by blowing from a ring without any external blades. Its blades are hidden in its base, but bladeless fans can produce more constant airflow than traditional fans. The air in the bladeless fan is drawn in by a fan in the base and then the flow is directed up into a ring. Then the airflow comes out of a crack all around the ring and passes over a shape like an aircraft wing. Because the flow passing the shape will increase its velocity and can also cause a lower pressure larger than the surrounding pressure, the air is led inside the ring and begins to move forward. The shape of the ring surface is very important if higher velocity of the air flow can be reached, then the fan can be more efficient. In this study, an aerodynamic and aeroacoustic performance of a bladeless fan with different ring shapes was investigated by numerical simulation, so we can find out how the shape of the ring will influence the air flow and we can also determine the flow increase ratio as the performance of the fan.