Patent ID: 7416386

Claim:
A heat dissipation apparatus, comprising: a fan frame having an air inlet, an air outlet, a passage, and a curved expansion portion, wherein the air inlet is opposite the air outlet and the passage is between the air inlet and the air outlet, guiding airflow from the air inlet to the air outlet, and the curved expansion portion, having a recess in which the airflow forms an airflow layer, is radially and outwardly extended from an inner peripheral wall of the passage at one of the air inlet and the air outlet; and an impeller disposed in the fan frame and having a plurality of blades, wherein each blade is disposed in the passage and has an extension end extending to the curved expansion portion, wherein the fan frame further comprises at least one curved concave formed in the curved expansion portion to create a wavy outline of the curved expansion portion, providing stabilization functions to the airflow.