Study On The CAD System For The Hydraulic Design Of Mixed-flow Pumps

A new CAD model for the hydraulic design of mixed-flow pumps is established. The CAD software, which is named MPCAD, is developed by means of AutoCAD's C/C++ developing environments-ObjectARX. In MPCAD, the new results in the recent study on the hydraulic design of mixed-flow pumps are introduced. The hydraulic calculating and drawing are combined together. The MPCAD software, has been applied to design the mixed-flow pumps. In this study, the impeller meridian plane and the center of the circle which is tangent with the hub and shroud can be determined interactively, after getting the main parameters for the impeller geometry. The one-dimensional theory is used to establish the initial two- dimensional stream lines. With the great functionality of Object ARX, the grid consisting of two-dimensional equipotential lines and stream lines can be generated automatically. The system provides many ways to give the distribution of var. By utilizing the AutoCAD's edit mechanism and the functionality of C/C++, the processing functions are written to generate the plane drawing and meridian section lines automatically. The volute section can be obtained by importing few parameters. The system adds intellectualized measurement annotation to a drawing. Some other utilities, such as formats setting for drawing paper, creating and reading of design documents, are provided to simplify the user's operation. In the computing and drawing processes mentioned above, both the automated realization and the interactive operation are integrated. Such a combination will profit from the designers'experiences and improve the efficiency of the whole system. The author's work builds up the foundation for the deep research on mixed-flow pumps CAD system, and has some practical value to the CAD study on the other types of pumps and turbines.