A fan with supercharging device has a hub and fan blades. A hub has a
shape similar to a cone with a tip end and a circumferential side. The
fan blades extend radially from the circumferential side of the hub. Each
of the fan blades has a joining end being attached to the circumferential
side, a free end extending outward the hub and a front edge and a rear
edge being between the joining end and the free end respectively. The
rear edge of the respective fan blade is shielded by the front edge of
another fan blade next to it. The unshielded portion of the respective
fan blade has an area gradually increases from the joining end to the
free end. A projection is disposed at the free end along a direction of
fluid flow. Hence, fluid pressure is capable of increasing significantly
while the fan is in operation.