Parametric Design System Based On Catia Centrifugal Fan, A Preliminary Study

The design system of Centrifugal Fans - the research object in this thesis could he realized quickly , expediently and accurately in the environment of CATIA (Computer Aided Three Dimensional Interactive Application) after the intellective calculation of the computer, which is on the base of the technology of the fan design that is on top in our country. CATIA is a three-dimensional engineering software, it can provide the functions of the strong three-dimensional sculpting and the correlativity between the two-dimensional models and the three-dimensional models which were used in the thesis.In the thesis, the author firstly expounds and summarizes the theory of fan design comparability in detail, then analyzes the fan product character( pressure-quantum curve), the geometrical shape and the geometrical restriction relations of centrifugal fans and the non-unit characteristics parameters table of them which come from the experiments of the fan models. The centrifugal fan style-choosing could be done according to the comparability theory, it can give the well-performanced fan quickly and correctly that satisfied the design requirement and can be manufactured easily. Secondly on the platform of CATIA, the three-dimensional sculpting of the centrifugal fan parts and components can be done, in which parameterization method and character-based technology are used to get the important character parameters of the centrifugal fan from its models; the technology of facing object and the dimension-driving function are used to make it realized. Finally in the developing environment of VB(Visual Basic), database technology and modularization software program are used to develop the system of fan design and the interface between user and computer. The system can output the engineering drawings of the designed fan , which finished the changing from three-dimensional products to two-dimensional drawings.In me thesis, the centrifugal fan design system includes type-choosing module, design module and accessorial functions module. It can realize centrifugal fan type-choosing , parameterized designing of the parts and assembling of the components. It will accelerate the automatism of fan design , reduce the cost of fan design effectively and shorten the developing cycle of the fan products, which will be significative for enhancing the market competence of the corporations using with it.