On the Simulation and Spectral Analysis of Unsteady Turbulence and Transition Effects in a Multistage Low Pressure Turbine
| Autor: | Anselm Moors, Georg Geiser, Anton Weber, Jens Wellner, Edmund Kügeler |
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| Rok vydání: | 2019 |
| Předmět: |
Suction
Materials science Turbines 02 engineering and technology Computational fluid dynamics 01 natural sciences Turbine 010305 fluids & plasmas Physics::Fluid Dynamics Flow separation Blades 0203 mechanical engineering Separation (Technology) 0103 physical sciences Pressure Emission spectrum Boundary value problem Spectroscopy 020301 aerospace & aeronautics Turbulence business.industry Mechanical Engineering Mechanics Emission spectroscopy Turbochargers Bubbles business Simulation Turbocharger |
| DOI: | 10.1115/1.4041820 |
| Popis: | A nonlinear full-wheel time-domain simulation of a two-stage low pressure turbine is presented, analyzed, and compared with the available experimental data. Recent improvements to the computational fluid dynamics (CFD) solver TRACE that lead to significantly reduced wall-clock times for such large scale simulations are described in brief. Since the configuration is characterized by significant unsteady turbulence and transition effects, it is well suited for the validation and benchmarking of frequency-domain methods. Transition, flow separation and wall pressure fluctuations on the stator blades of the second stage are analyzed in detail. A strong azimuthal π-periodicity is observed, manifesting in a significantly varying stability of the midspan trailing edge flow with a quasi-steady closed separation bubble on certain blades and highly dynamic partially open separation bubbles with recurring transition and turbulent reattachment on other blades. The energy spectrum of fluctuating wall quantities in that regime shows a high bandwidth and considerable disharmonic content, which is challenging for frequency-domain-based simulation methods. |
| Databáze: | OpenAIRE |
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