TY - JOUR

T1 - An improved reduced order model for bladed disks including multistage aeroelastic and structural coupling

AU - Schwerdt, Lukas

AU - Maroldt, Niklas

AU - Scheidt, Lars Panning Von

AU - Wallaschek, Joerg

AU - Seume, Joerg

N1 - Funding Information: The authors gratefully acknowledge the funding of the present work through CRC 871 “Regeneration of Complex Capital Goods”, funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB 871/3 – 119193472. Funding Information: The authors would like to acknowledge the substantial contribution of the DLR Institute of Propulsion Technology and MTU Aero Engines AG for providing TRACE. Funding sources The authors gratefully acknowledge the funding of the present work through CRC 871 “Regeneration of Complex Capital Goods”, funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB 871/3 – 119193472.

PY - 2023/4/25

Y1 - 2023/4/25

N2 - To assess the influence of mistuning on the vibration amplitudes of turbo-machinery rotors, reduced order models (ROMs) are widely used. A variety of methods are available for single-stage configurations and mostly aero-elastic effects can be taken into account. More recent research focusses on extending these methods to include multiple stages. However, due to the significantly increased computational effort of the aeroelastic simulations when adding more stages to the models, these ROMs are rarely applied with the inclusion of multistage aeroelastic effects. It is therefore desirable to develop reduction methods which minimize the number of these simulations to reduce the computational cost and thereby enable analyses of rotors with multiple stages including aeroelastic effects. In this paper, a cyclic Craig-Bampton reduction method with an a priori interface reduction for multistage rotors is extended with an additional a posteriori interface reduction to reduce the number of aeroelastic simulations necessary for a given accuracy level of the ROM. The interface degrees of freedom between stages are reduced using a modified version of Characteristic Constraint Modes, to yield a more efficient representation of their displacements while retaining their monoharmonic nature. The method is applied to a two-stage axial compressor with full aeroelastic coupling between the stages and its reduced computational effort is demonstrated. Additionally, two sorting methods for the degrees of freedom (DOFs) of the ROM are compared.

AB - To assess the influence of mistuning on the vibration amplitudes of turbo-machinery rotors, reduced order models (ROMs) are widely used. A variety of methods are available for single-stage configurations and mostly aero-elastic effects can be taken into account. More recent research focusses on extending these methods to include multiple stages. However, due to the significantly increased computational effort of the aeroelastic simulations when adding more stages to the models, these ROMs are rarely applied with the inclusion of multistage aeroelastic effects. It is therefore desirable to develop reduction methods which minimize the number of these simulations to reduce the computational cost and thereby enable analyses of rotors with multiple stages including aeroelastic effects. In this paper, a cyclic Craig-Bampton reduction method with an a priori interface reduction for multistage rotors is extended with an additional a posteriori interface reduction to reduce the number of aeroelastic simulations necessary for a given accuracy level of the ROM. The interface degrees of freedom between stages are reduced using a modified version of Characteristic Constraint Modes, to yield a more efficient representation of their displacements while retaining their monoharmonic nature. The method is applied to a two-stage axial compressor with full aeroelastic coupling between the stages and its reduced computational effort is demonstrated. Additionally, two sorting methods for the degrees of freedom (DOFs) of the ROM are compared.

KW - aerolatics

KW - reduced order modelling

KW - substructuring

UR - http://www.scopus.com/inward/record.url?scp=85159186796&partnerID=8YFLogxK

U2 - 10.33737/jgpps/161707

DO - 10.33737/jgpps/161707

M3 - Article

AN - SCOPUS:85159186796

VL - 7

SP - 140

EP - 152

JO - Journal of the Global Power and Propulsion Society

JF - Journal of the Global Power and Propulsion Society

ER -