Parametric Study of Centrifugal Fan Performance: Experiments and Numerical Simulation

In this paper, effect of geometric parameters of a centrifugal fan with backwardand forward-curved blades has been investigated. Centrifugal fans are used for enhancing the heat dissipation from the IC engine surfaces. In the process, the fan consumes power generated from the engine. As a first step, an experimental setup was developed and prototypes of fans were made to carry out measurements of flow and power consumed by the fan. The fan mounting setup was such that fan with uniform blades can be tested. Generally, fans have cut blades on the vehicle due to mounting accessories. We describe a patented design of shaft that would enable mounting of fan with uniform blades on the vehicle. Next, a computational fluid dynamics (CFD) model was developed for the above setup and the results are validated with the experimental measurement. Further, parametric studies were carried out to quantify the power coefficient, flow coefficient, efficiency and flow coefficients. The parameters considered in this study are number of blades, outlet angle and diameter ratio. The results suggest that fan with different blades would show same performance under high-pressure coefficient. However, the difference between the performances becomes distinct under low pressure coefficients suggesting that the fan performance testing should not be done on vehicle level where high pressure coefficients is observed due to various resistances in the system. The results show that increase in flow coefficient is accompanied by decrease in efficiency and increase in power coefficient. Effect on the vehicles mileage due to the use of forward and backward fan is also discussed. In summary, this study presents a systematic and reliable strategy to investigate the centrifugal fan performance in automotive applications.