الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Centrifugal compressors play an important role in many industries. Increasing the aerodynamic efficiency of new designs while maintaining structural strength, manufacturability and reduced costs is the designer’s target. Classical centrifugal compressors design methodologies produced designs that are highly manufacturable and have good structural properties through using simple geometrical configurations utilizing simple elliptical, circular, or parabolic arcs for the definition of meridional contour and blade camber line. Using experimentation and good design practices, good designs with good aerodynamic efficiency could be obtained. Modern designers take the advantage of computational fluid dynamics, structural analysis, process integration and optimization software to design new, optimized centrifugal compressors from scratch using an automated workflow. These compressors have optimized aerodynamic efficiencies that exceed the efficiency of classical designs through adding complex geometrical features. This is possible as modern designs use Bezier or spline curves for meridional contour and blade camber line definitions. The shape of these curves is easily controllable through the coordinates of their control points, so, the coordinates of the control points are used as variables controlled by the optimizer to automatically change the design geometry. The performance of each design is evaluated using CFD and the iterative process progresses automatically in a manner determined by the optimization technique. Structural and dynamics software can be used during the optimization process or just for checking the validity of the new aerodynamically- optimized design. this study, four classical geometrical configurations are parametrized and optimized using an automated aerodynamic optimization workflow. The geometry is controlled only through four parameters making the optimization process much faster compared to modern designs. In addition, the structural strength and manufacturability of the resulting designs are guaranteed. One hybrid configuration sharing the same circular arcs meridional contour of the Eckardt rotor O and utilizing Bezier curves, with a limited number of controllable parameters for blade angles definition, is finally optimized using the same automated optimization work. The Eckardt rotor O test case is selected for mesh validation, also most of the main dimensions of the Eckardt rotor O and all the diffuser dimensions are kept the same for all the optimized rotors such that the performance of the optimized designs could be compared to the performance of the Eckardt rotor O. The optimization target is to maximize the efficiency of the rotors at the following performance point: mass flow rate = 5.31 kg/s and rotational speed 14000 rpm. At the specified performance point, the classical pre-optimized inlet configurations achieve slightly higher efficiencies compared to the Eckardt rotor “O”. The hybrid configuration also achieves higher efficiency. In contrast, the radial blade element classical configurations, that don’t have pre-optimized inlets, achieve lower efficiencies compared to the Eckardt rotor “O”.