Influence of Geometric Parameters on the Average Outlet Velocity of the Bladeless Fan

Abstract

After the development of bladeless fans, design considerations about the fan models have been changed. However, developing an optimum bladeless fan based on geometric parameters is essential due to their possible future applications. In this study, the effect of three geometric parameters such as Coanda surface curvature, bladeless fan cross-section thickness and nozzle outlet gap on the performance of different bladeless fan designs are investigated. These unique features have a significant impact on the bladeless fan's performance. This research uses numerical simulations to get a better understanding of the effects of these three parameters on the performance and the average outlet velocity of bladeless fans. To observe the velocity distribution of the air inside the bladeless fan chamber and average outlet velocity magnitude at the nozzle outlet, ANSYS-Fluent software is used to do three-dimensional numerical simulations. Based on a simplified bladeless fan concept, different bladeless fan cross-sections are designed by changing these three parameters and CFD simulations conducted on these models. It is found that the nozzle outlet gap has the strongest effect on the outlet velocity magnitude of the fan as expected. On the other hand, the other two parameters that choose have significant effects on flow distribution and aerodynamic performance of the bladeless fan. Fan cross-section thickness is a crucial parameter for the internal flow turbulence characteristics inside the bladeless fan ring. This research will be valuable in improving the performance of bladeless fans and will give useful ideas about optimum fan design.