Centrifugal Fan CFD Analysis for Predicting its Aerodynamics
A centrifugal fan (often called squirrel cage fan) is a mechanical device used for moving air or other gases. Due to their simple design, centrifugal fans are manufactured easier than other types of fans, which saves time and costs. This makes them a popular choice for air handling applications.
Through their rotating impellers, with either forward- or backward-curved blades, centrifugal fans increase the speed and volume of an air stream and have superior aerodynamic properties compared to axial fans, for example.
Energy efficiency (reaching up to 84% static efficiency), durability even in corrosive environments, easy maintenance and suitability for multiple airflow / pressure combinations are the main advantages that engineers consider when choosing them for HVAC applications.
How to Predict a Centrifugal Fan’s Aerodynamic Efficiency?
As mentioned above, its aerodynamics is one of the best advantages of a centrifugal fan. This is why during the design process, it is important to make sure that design engineers make the most out of its properties to maximize efficiency. This is when computational fluid dynamics (CFD) simulations come into play.
CFD is the method used for the computerized calculation of fan aerodynamic quality to accurately predict its performance early in the design stage, analyze various CAD models, reduce the number of physical prototypes and expensive testing and optimize the design for maximum performance.
SimScale’s CFD solution allows fan designers to calculate flow rates, static pressure, total pressure, static efficiency, total efficiency, peak total efficiency, forces and moments acting on the fans and more, 100% in the browser, giving flexibility, collaboration options and access to high computing power — up to 32 cores —from a normal PC or laptop.
CFD Analysis of a Centrifugal Fan Design
An example is this CFD analysis, which was performed on the design of a centrifugal radial compact fan with forward-curved impeller. This type of fans are used for electronics cooling applications such as thermal management for the infotainment, IT and telecom systems.
The goal for the 3D simulation was to predict the fan’s aerodynamic performance and identify areas for design optimization.
The contours below show a 3D visualization of static pressure, flow velocity and the aerodynamic forces acting on the rotor. The performance curves obtained from this analysis are key indicators for deciding whether the design meets the requirements or needs optimization.