Schnoes, Markus and Schmitz, Andreas and Goinis, Georgios and Voß, Christian and Nicke, Eberhard (2019) Strategies for Multi-Fidelity Optimization of Multi-Stage Compressors with Throughflow and 3D CFD. ISABE 2019, 2019-09-23 - 2019-09-27, Canberra, Australia.
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Abstract
The aerodynamic design of turbomachinery is an exciting engineering problem that involves a vast design space and requires proficiency in multiple engineering disciplines. For multi-stage compressors, the large dimension of the design space arises from the geometric freedom to shape each blade row individually. Although the basis of most designs is formed by throughflow computations, the state-of-the art for aerodynamic evaluation is steady-state RANS. The computational expense for a single evaluation of a multi-stage machine with RANS is affordable, shape optimizations with hundreds of evaluations becomes expensive. This paper presents two strategies to tackle these problems: Firstly, a novel airfoil family is employed that helps to reduce the number of design parameters. It was generated based on a parametric study of optimal airfoil shape for varying design requirements. Secondly, an optimizer is used that supports simultaneous evaluations of the objective function on multiple fidelity levels. Here, cheap throughflow calculations are conducted on the low-fidelity side and RANS is used on the high-fidelity side. Inside the optimizer, multi-fidelity support is enabled by a Co-Kriging surrogate model. This approach is expected to speed-up the optimization by guiding expensive evaluations of the 3D CFD setup into promising regions of the design space. These strategies are assessed by testing different optimization setups for a four stage compressor. Both purely low and high-fidelity optimizations are conducted as well as multi-fidelity optimizations. In comparison to the baseline design, the isentropic efficiency predicted by RANS for the working line points on the 95% and the 100% speed line is increased by above 1.2%. The driving mechanism is a load redistribution between the stages that mainly reduces the shock strength of the second rotor.
Item URL in elib: | https://elib.dlr.de/129457/ | ||||||||||||||||||||||||
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Document Type: | Conference or Workshop Item (Speech) | ||||||||||||||||||||||||
Title: | Strategies for Multi-Fidelity Optimization of Multi-Stage Compressors with Throughflow and 3D CFD | ||||||||||||||||||||||||
Authors: |
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Date: | September 2019 | ||||||||||||||||||||||||
Refereed publication: | Yes | ||||||||||||||||||||||||
Open Access: | Yes | ||||||||||||||||||||||||
Gold Open Access: | No | ||||||||||||||||||||||||
In SCOPUS: | No | ||||||||||||||||||||||||
In ISI Web of Science: | No | ||||||||||||||||||||||||
Status: | Published | ||||||||||||||||||||||||
Keywords: | Design Optimization, Throughflow, 3D CFD, Compressor, Co-Kriging, Multi-Fidelity | ||||||||||||||||||||||||
Event Title: | ISABE 2019 | ||||||||||||||||||||||||
Event Location: | Canberra, Australia | ||||||||||||||||||||||||
Event Type: | international Conference | ||||||||||||||||||||||||
Event Start Date: | 23 September 2019 | ||||||||||||||||||||||||
Event End Date: | 27 September 2019 | ||||||||||||||||||||||||
HGF - Research field: | Aeronautics, Space and Transport | ||||||||||||||||||||||||
HGF - Program: | Aeronautics | ||||||||||||||||||||||||
HGF - Program Themes: | propulsion systems | ||||||||||||||||||||||||
DLR - Research area: | Aeronautics | ||||||||||||||||||||||||
DLR - Program: | L ER - Engine Research | ||||||||||||||||||||||||
DLR - Research theme (Project): | L - Fan and Compressor Technologies (old) | ||||||||||||||||||||||||
Location: | Köln-Porz | ||||||||||||||||||||||||
Institutes and Institutions: | Institute of Propulsion Technology > Fan and Compressor | ||||||||||||||||||||||||
Deposited By: | Schnös, Markus | ||||||||||||||||||||||||
Deposited On: | 18 Nov 2019 12:12 | ||||||||||||||||||||||||
Last Modified: | 24 Apr 2024 20:32 |
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