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Fans and Blowers

An important goal of thermal engineers is to accurately predict the air flow through the fan or blower after it is installed in a system. In addition to predicting the amount of flow generated by the fan/blower, the designer also needs an accurate estimate of the flow distribution leaving the fan/blower, as it affects the heat sink performance.

Due to high turbulence the air flow inside the system is complex. Fan and blower performance is highly sensitive to their inlet and outlet design (e.g. as a result of system blockage). As a result, representing the fan through a universal fan curve obtained under the standard testing conditions of a free inlet, is not always accurate.

Designers can attain greater accuracy by explicitly modeling the fan/blower, including the blade details, as an integral part of the global system model. Fluent's CFD software allows designers to do computer simulations of the air flow in fans under actual installed conditions. CFD gives designers the power to visualize the performance of their designs and spot areas for further optimization. It also enables designers to reduce the number of design iterations since the inclusion of the details of the fan yields a more accurate prediction of the amount of air flow. This greatly reduces the amount of physical testing and expedites the product's release to market.

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Fluent's CFD model revealed separated flow and high loss at the exit of this centrifugal blower

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A 2D model of a crossflow fan is shown in this animation. Air is drawn in from far field boundaries on the left and top boundaries, and ejected into the channel in the lower right. The sliding mesh model was used for the simulation