Development of a fast, automatic and effective computer-aided design and optimization tool for centrifugal compressor impellers has attracted great attention and interest both in industry and academia because centrifugal compressors are widely used and more stringer criteria such as shorter design cycle time and higher efficiency has been proposed by consumers.;In my study, a centrifugal compressor impellers optimization procedure is established. A geometry generation tool is developed; a flow solver with streamline curvature method is modified and linked to this geometry generation tool. This geometry generation tool with the flow solver is used to generate the geometry cases and calculate their corresponding performance to form a database. Two types of Artificial Neural Networks (ANNs): Feed-forward Neural Network (FFNN) and Radial Basis Function Network (RBFN) are used to create the performance map of centrifugal compressor impellers based on this database. Genetic Algorithm (GA) used as the optimization method to search the optimal geometry based on given desired conditions.;Furthermore, Principle Component Analysis (PCA) or Independent Component Analysis (ICA) is applied to improve optimization procedure by transforming training database and make the creating of the performance map in a new coordinate system. The aim of applications of PCA or ICA is to decrease the errors caused by approximate performance map. In this dissertation, the accuracies of three different trained ANNs: RBFN, RBFN with PCA, and RBFN with ICA. As well as total of centrifugal compressor impeller optimization procedures using these three different trained ANNs are compared.;An online flow solver is also developed to overcome the drawbacks of modeling tools, in which the flow solver is used directly to evaluate the performances of centrifugal compressor impellers. This optimization procedure is compared with offline flow solver optimization procedure Furthermore; influences of GA operators, parameters and local search algorithm on online and offline flow solver optimization procedure are also investigated.;Finally, an industrial centrifugal compressor impeller designed by Solar Turbine Inc. is optimized by using five different types of optimization procedures and new impeller geometries are evaluated by ANSYS CFX.;Results show that GA has a good performance on this optimization problem and PCA greatly increase the accuracy of created performance maps and following optimization performances. It is indicated the developed optimization tool is capable of finding an impeller geometry, which has the exact desired relative velocity distribution. Online flow solver and offline flow solver with PCA optimization procedures have best performance for achieving desired velocity distribution. However, results of CFX suggest that ail online flow solvers, offline flow solver with PCA and RBFN, offline flow solver with FFNN optimization procedures are capable of reaching the desired efficiencies.
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