Wegt, Sebastian (2022)
Computational characterization of flow and turbulence in IC engine-relevant cooling channels: An LES- and Reynolds-stress-modeling study.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00020353
Ph.D. Thesis, Primary publication, Publisher's Version
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | Computational characterization of flow and turbulence in IC engine-relevant cooling channels: An LES- and Reynolds-stress-modeling study | ||||
Language: | English | ||||
Referees: | Jakirlic, apl. Prof. Suad ; Hussong, Prof. Dr. Jeanette ; Breuer, Prof. Dr. Michael | ||||
Date: | 2022 | ||||
Place of Publication: | Darmstadt | ||||
Collation: | xiv, 336 Seiten | ||||
Date of oral examination: | 15 December 2021 | ||||
DOI: | 10.26083/tuprints-00020353 | ||||
Abstract: | The present work provides an insight into the flow topology of common pipe structures with the newly designed Water Spider Geometry (WSG) as a generic flow guidance of an Internal Combustion (IC) engine cooling channel, which includes flow deflection (90°-pipe bend), division (T-junction) and confluence (reverse T-junction). Therefore, a cost-efficient Large-Eddy Simulation (LES) framework for pipe structures is elaborated, which satisfies the well-known quality criteria defined in literature. The associated flow discussions enable an application-oriented assessment of the pipe structures with the focus on critical wall-abrasive flow conditions. Positions of pronounced surface degradation within the WSG detected by complementary conducted experiments (see Klink et al., 2019, and Klink and Wegt, 2021) could be attributed to the flow topology and appropriate countermeasures postulated. As a special feature, the vortex identification methodology according to Graftieaux et al. (2001) is applied to the flow discussions, which enables the identification of characteristic vortex topologies and their formation mechanisms. For further investigations within the WSG framework, an homogeneous-dissipation-concept-based elliptic-blending-related Reynolds-stress model (EBM) is formulated, calibrated and validated with a multitude of well-known benchmark cases. The formulation is based on the suggestions of Manceau and Hanjalic (2002) and Jakirlic and Maduta (2015) and combines the advantageous elliptic blending procedure for the pressure redistribution with the homogeneous specific dissipation rate concept. Furthermore, the phenomenon 'backbending' could be reliably avoided within the considered benchmark cases by a reformulation of the Simple Gradient Diffusion Hypothesis (SGDH). The extensive validation study including the WSG demonstrates the capability of the EBM to reproduce a variety of flow phenomena and confirms its suitability for further investigations. |
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Status: | Publisher's Version | ||||
URN: | urn:nbn:de:tuda-tuprints-203537 | ||||
Classification DDC: | 600 Technology, medicine, applied sciences > 620 Engineering and machine engineering | ||||
Divisions: | 16 Department of Mechanical Engineering > Fluid Mechanics and Aerodynamics (SLA) > Modelling and simulation of turbulent flows | ||||
Date Deposited: | 09 Feb 2022 15:02 | ||||
Last Modified: | 09 Feb 2022 15:02 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/20353 | ||||
PPN: | 491473648 | ||||
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