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Extension of Centrifugal Compressor Operational Stability
Růžička, Miroslav ; Třetina, Karel (referee) ; Kmoch, Petr (referee) ; Klement, Josef (advisor)
Centrifugal compressors with high pressure ratio are widely used in small aircraft turbine engines and turbocharges. At high rotational speeds they have narrow stable operating region and commonly used impellers with back swept blades are not able to ensure requested stability. In order to achieve wider stable operating region, some other anti-surge measures can be used, such as an Internal Recirculation Channel (IRC) located in compressor impeller inlet. This thesis deals with an investigation of IRC influence on centrifugal compressor operational parameters. As a first, the various recirculation channel geometry was studied by using of CFD analysis on simplified computational models. Those geometry, which indicated best results in terms of mass flow and looses in channel were used for testing on a model test device. Subsequently the same geometry was tested on real centrifugal compressor in experimental turbine engine to verify influence of IRC on compressor performance map – pressure ratio and efficiency. Simultaneously the CFD analyses of IRC with a 3D model of compressor impeller were performed and results compared with those, gained from measurement on model and compressor. In addition the measurement of flow field downstream the recirculation channel outlet slot with using of 3-hole pressure probe was performed and compared with flow velocity profiles evaluated from numerical simulations.
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Analysis of the Effects of Internal Recirculation Channel of a Radial Compressor on Extending the Stable Working Area
Paulík, Lukáš ; Vacula, Jiří (referee) ; Novotný, Pavel (advisor)
The extension of the stable working area is very important especially for the radial compressors used in turbochargers. Compressors with high pressure ratio have a narrow stable operating region, which limits their practical use. One of the frequent modifications on radial compressor, concerning the extension of its range of stable work, is installation of an internal recirculation channel (IRC) in its inlet section. CFD programs are often used to simulate the flow through the turbomachines for optimizing the design of the IRC. Based on the extensive research, regarding the flow in the IRC and its location in the inlet of the compressor, suitable variants of its design were selected and applied to a radial compressor of the turbocharger. By simulating the flow in a radial compressor with the IRC, using Ansys CFX software, the compressor performance maps were determined. The best design of the IRC which meets the requirements for extending its stable working area was selected by evaluating the results of the simulations.
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Extension of Centrifugal Compressor Operational Stability
Růžička, Miroslav ; Třetina, Karel (referee) ; Kmoch, Petr (referee) ; Klement, Josef (advisor)
Centrifugal compressors with high pressure ratio are widely used in small aircraft turbine engines and turbocharges. At high rotational speeds they have narrow stable operating region and commonly used impellers with back swept blades are not able to ensure requested stability. In order to achieve wider stable operating region, some other anti-surge measures can be used, such as an Internal Recirculation Channel (IRC) located in compressor impeller inlet. This thesis deals with an investigation of IRC influence on centrifugal compressor operational parameters. As a first, the various recirculation channel geometry was studied by using of CFD analysis on simplified computational models. Those geometry, which indicated best results in terms of mass flow and looses in channel were used for testing on a model test device. Subsequently the same geometry was tested on real centrifugal compressor in experimental turbine engine to verify influence of IRC on compressor performance map – pressure ratio and efficiency. Simultaneously the CFD analyses of IRC with a 3D model of compressor impeller were performed and results compared with those, gained from measurement on model and compressor. In addition the measurement of flow field downstream the recirculation channel outlet slot with using of 3-hole pressure probe was performed and compared with flow velocity profiles evaluated from numerical simulations.
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Extension of Centrifugal Compressor Operational Stability
Růžička, Miroslav ; Klement, Josef (advisor)
Centrifugal compressors with high pressure ratio are widely used in small aircraft turbine engines and turbocharges. At high rotational speeds they have narrow stable operating region and commonly used impellers with back swept blades are not able to ensure requested stability. In order to achieve wider stable operating region, some other anti-surge measures can be used, such as an Internal Recirculation Channel (IRC) located in compressor impeller inlet. This thesis deals with an investigation of IRC influence on centrifugal compressor operational parameters. As a first, the various recirculation channel geometry was studied by using of CFD analysis on simplified computational models. Those geometry, which indicated best results in terms of mass flow and looses in channel were used for testing on a model test device. Subsequently the same geometry was tested on real centrifugal compressor in experimental turbine engine to verify influence of IRC on compressor performance map – pressure ratio and efficiency. Simultaneously the CFD analyses of IRC with a 3D model of compressor impeller were performed and results compared with those, gained from measurement on model and compressor. In addition the measurement of flow field downstream the recirculation channel outlet slot with using of 3-hole pressure probe was performed and compared with flow velocity profiles evaluated from numerical simulations.
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