Investigations on Twisted Blade for Axial Microfan

Abstract

By ‘Radial Equilibrium’ principle, an equation was derived to describe the radial distribution of the throughflow velocity, by which a design approach was proposed for the twisted blade of axial microfan. This approach can take into consideration the influence of the radial gradient for the throughflow velocity at the impeller’s outlet, which is different from the traditional design approach for large fans assuming the throughflow velocity remains radially unchangeable. By this design approach, attempt was made on the design for an axial microfan by choosing different twisted powers so as to obtain different shapes of twisted blades and their respective aerodynamic performance was numerically investigated. Compared to the corresponding straight blade and the twisted blade designed by the traditional approach, this new twisted blade can not only enlarge the stable operating range but also improve the flow pressure, which contributes to the improvement of the blade’s aerodynamic performance.