Structure Analysis And CAD Software Of Centrifugal Fan In Domestic Air-conditioner

This paper presents the structure analysis and CAD software of centrifugal fan in domestic air-conditioner. By using finite element analysis method, some key structure parameters of fan are studied to find out their different effects on inherent frequency of fan in air-conditioner. Accordingly, a structure CAD software "FanDesign for Windows" is integrated with'Visual C++. This paper includes three sections: structure analysis of fan blade, structure analysis of centrifugal fan, CAD software.Firstly, some basic theories and concepts including modal analysis theory, finite element analysis method used in structure analysis, inherent frequency, and modes of vibration are discussed. Then a single blade of fan is used to analyze the effects of different length of blade and different chord length of blade on its inherent frequency for the purpose of the study in the course of design.In the second section, through the related theories, a simplified calculation model for the fan is proposed and applied to analyze the low order vibration conditions as well as some key structure parameters' effects on inherent frequency of centrifugal fan, which are characterized by the length of blade, the chord length of blade, the angle of air-inlet of fan and the material of fan. Finally, the effect of fan structural parameters on the centrifugal fan in air-conditioner in frequency domain is investigated.The software is designed with an Object Oriented Programming (OOP), which can be maintained and extended conveniently. The User Interface (UI) has favorablemaneuverability, which satisfies the software engineering standard. The data in this study are used to form the database. The database structure is designed with Microsoft Access and its program interface is realized with Visual C++. The OpenGL 3-D Graphics lib is used to show the shape of 3-D blade.