1. The Fundamental Principle: How Axial Fans Achieve Linear Airflow The axial fan is the most ubiquitous form of air-moving machinery, defined by its core operating principle: moving gas parallel to the axis of the rotating shaft[1]. Unlike centrifugal fans axial ac, which move air radially (at a 90-degree angle), axial ac fans draw air in and discharge it in a straight line, making them ideal for high-volume, low-pressure applications[2][3]. This linear flow is achieved through the aerodynamic design of the fan blades, which function similarly to an airplane's wing or propeller[4]. As the motor drives the hub and the attached blades to rotate, the airfoil shape of each blade creates a pressure differential[2]. The convex (curved) side of the blade experiences lower pressure, while the concave (flatter) side experiences higher pressure.