Aerofoil advantages in fan blades

Vrushali Joshi Mukherjee, Sandevin Analytics

As one of the nation’s premier heat transfer products firms noted in their seminars on Tier IV requirements, “Outside of the core, the fan is the most important component of the cooling package.”
Aerofoil fan blades provide efficiency and low noise using classic aerofoil design. Aerofoil fans provide uniform, high volume airflow with low power consumption for optimum efficiency using the same aerodynamics that create thrust. Aerofoil fans have a round leading edge, a sharp trailing edge, and in profile or cross section, look similar to a teardrop that has been flattened on one side. As air approaches the blade’s leading edge, the stream splits and travels above and below the blade. Air is deflected across the convex curve along the top of the blade and along the flat or concave curve on the bottom of the blade, and flows downward over the sharp trailing edge as it leaves the blade.


According to Bernoulli’s Principle, the faster moving air across the top of the blade creates less pressure than the slower moving air on the bottom of the blade. This creates lift in an airplane wing or airflow in a fan. Aerofoil fans function just like a series of small airplane wings attached to a hub, with one notable exception. In axial fans, the aerofoil’s twisted design ensures that the incident angle between the aerofoil and the airflow is constant along the blade length, giving a uniform blade loading for high efficiency, low noise fans.
Many factors have influence on designing high quality fans. Some factors are relative to fan noise. The fan noise will be controlled reasonably from the model, especially from the mechanism of fan blade shape. The optimization theory is used in the design of high-quality fans too. But every property of the fan has different weighting factors in the design and in the development stages. The fan blade shape parameters, such as the number of blades, rotational speed of fan, chord of fan, and blade profile etc. affect the Sound Pressure Level.

Following are some benefits of using aerofoil design in Fan blades :
• Increases the spread and velocity of fan blade, which helps to increase Air Delivery.
• There are no sharp edges as such, it helps to reduce noise.
• Camber in the Aerofoil helps with Air delivery with increasing pitch of the blade. Hence it reduces the torque induced to deliver same amount of air.
• In Aerofoil fans weight variation is possible as per requirement.
• Aerofoil blade fans are aesthetically better. Due to reduction in torque and noise the efficiency of Aerofoil blade fans is comparatively high then normal fan blades and gives better performance over normal fan blades.