The Study of the Effects of Blade Design on a Small Axial Fans

• Main Authors: Kun-Tse Lai, 賴昆澤
• Other Authors: Shiu-guang Liou
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/42879177311452407259

碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 100 === The main purpose of this study is to examine the effects of blade design on the aerodynamic performance of a small axial fan. Model of Xinruilian’s RD1232, including the shroud and the blades, were prepared using SolidWorks and then imported into ANSYS-CFX for numerical simulation. In the process, effects of modifying stagger angle, chord length, airfoil thickness, camber angle, chamfer angle of the leading edge at the blade tip, and the blade numbers on the performance of the fan under different back pressure were first evaluated. Conclusions drawn were then applied on special cases in order to confirm its applicability on different fans. Various contour plots and data were used to evaluated the effects of different design parameters and its mechanism. According to the results, each design change can cause different degrees of impact on fan’s performance, with solidity ratio, stagger angle and airfoil thickness having the most profound effects. When the stagger angle is reduced, the area with negative pressure distribution on the suction side of the blade enlarges due to the increase of the angle of attack, which enhances the induction of the air flow at the entrance and advances the volume flow rate. On the other hand, reducing airfoil’s thickness will increase the internal passage space and improve the flow rate as well. In addition, reducing airfoil staggered angle and thickness can also help to guide the air flow toward the axial direction under different pressure conditions, which is one of the main reason for improvement on the volume flow rate. Besides, results on the special cases indeed demonstrate the effectiveness of the abovementioned conclusions on different fans.