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Implementation and Performance of Wall Models for Large Eddy Simulation of Non-equilibrium Turbulent Boundary Layers
Implementation and Performance of Wall Models for Large Eddy Simulation of Non-equilibrium Turbulent Boundary Layers
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211151317
- ISBN
- 9798382830070
- DDC
- 621
- 저자명
- Hayat, Imran.
- 서명/저자
- Implementation and Performance of Wall Models for Large Eddy Simulation of Non-equilibrium Turbulent Boundary Layers
- 발행사항
- [Sl] : University of Pennsylvania, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 157 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-12, Section: B.
- 주기사항
- Advisor: Park, George Ilhwan.
- 학위논문주기
- Thesis (Ph.D.)--University of Pennsylvania, 2024.
- 초록/해제
- 요약Accurate prediction of high-Reynolds-number wall-bounded turbulent flows is essential for the understanding and flow control of many engineering applications such as aircraft, turbomachinery, and marine vehicles. Additionally, most practical flows exhibit nonequilibrium effects such as pressure gradient, flow separation, and mean three-dimensionality. However, the direct numerical simulation (DNS) of high-Reynolds-number wall-bounded turbulent flows is not feasible owing to the prohibitive computational cost of resolving small-scale eddies near the wall. Wall-modeled large-eddy simulation (WMLES) presents an affordable predictive alternative to the DNS via the approximate modeling of flow physics near the wall (through a wall model) while resolving the outer (larger) scales directly on the computational grid. In this work, we focus on two aspects of wall models, (i) development and implementation of new/existing wall models, and (ii) application and comparison of different wall models in various nonequilibrium turbulent boundary layers. In the first part, we develop a novel spectral formulation for the ODE equilibrium wall model, showing its superior efficiency over the traditional approach. Furthermore, we extend the integral nonequilibrium wall model to an unstructured-grid LES solver. In the second part, we explore three wall models with varying degrees of computational complexity and physical fidelity, to assess their performance in two controlled but reasonably realistic nonequilibrium flows over a flat plate. The first flow features a turbulent boundary layer undergoing a series of complex pressure gradient effects, while the second exhibits turbulent flow separation induced by suction and blowing. While in the latter case, the more complex model clearly produces a superior prediction of the wall shear stress, the same is not necessarily true in the former case, highlighting that there still exists the need to adapt the existing wall models to different flow physics by modifying their underlying formulation or assumptions. Finally, a physic-based decomposition of skin friction, that shows separable contributions from various physical processes in the flow, is employed to explain the differing mechanisms of success/failure of wall models in different flows.
- 일반주제명
- Mechanical engineering
- 일반주제명
- Applied physics
- 일반주제명
- Computer science
- 일반주제명
- Naval engineering
- 키워드
- Turbulence
- 키워드
- Wall modeling
- 기타저자
- University of Pennsylvania Mechanical Engineering and Applied Mechanics
- 기본자료저록
- Dissertations Abstracts International. 85-12B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520250211151317
■006m o d
■007cr#unu||||||||
■020 ▼a9798382830070
■035 ▼a(MiAaPQ)AAI31238762
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a621
■1001 ▼aHayat, Imran.
■24510▼aImplementation and Performance of Wall Models for Large Eddy Simulation of Non-equilibrium Turbulent Boundary Layers
■260 ▼a[Sl]▼bUniversity of Pennsylvania▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a157 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 85-12, Section: B.
■500 ▼aAdvisor: Park, George Ilhwan.
■5021 ▼aThesis (Ph.D.)--University of Pennsylvania, 2024.
■520 ▼aAccurate prediction of high-Reynolds-number wall-bounded turbulent flows is essential for the understanding and flow control of many engineering applications such as aircraft, turbomachinery, and marine vehicles. Additionally, most practical flows exhibit nonequilibrium effects such as pressure gradient, flow separation, and mean three-dimensionality. However, the direct numerical simulation (DNS) of high-Reynolds-number wall-bounded turbulent flows is not feasible owing to the prohibitive computational cost of resolving small-scale eddies near the wall. Wall-modeled large-eddy simulation (WMLES) presents an affordable predictive alternative to the DNS via the approximate modeling of flow physics near the wall (through a wall model) while resolving the outer (larger) scales directly on the computational grid. In this work, we focus on two aspects of wall models, (i) development and implementation of new/existing wall models, and (ii) application and comparison of different wall models in various nonequilibrium turbulent boundary layers. In the first part, we develop a novel spectral formulation for the ODE equilibrium wall model, showing its superior efficiency over the traditional approach. Furthermore, we extend the integral nonequilibrium wall model to an unstructured-grid LES solver. In the second part, we explore three wall models with varying degrees of computational complexity and physical fidelity, to assess their performance in two controlled but reasonably realistic nonequilibrium flows over a flat plate. The first flow features a turbulent boundary layer undergoing a series of complex pressure gradient effects, while the second exhibits turbulent flow separation induced by suction and blowing. While in the latter case, the more complex model clearly produces a superior prediction of the wall shear stress, the same is not necessarily true in the former case, highlighting that there still exists the need to adapt the existing wall models to different flow physics by modifying their underlying formulation or assumptions. Finally, a physic-based decomposition of skin friction, that shows separable contributions from various physical processes in the flow, is employed to explain the differing mechanisms of success/failure of wall models in different flows.
■590 ▼aSchool code: 0175.
■650 4▼aMechanical engineering
■650 4▼aApplied physics
■650 4▼aComputer science
■650 4▼aNaval engineering
■653 ▼aLarge-eddy simulation
■653 ▼aTurbulence
■653 ▼aTurbulent boundary layers
■653 ▼aWall modeling
■653 ▼aWall-modeled large-eddy simulation
■690 ▼a0548
■690 ▼a0984
■690 ▼a0215
■690 ▼a0468
■71020▼aUniversity of Pennsylvania▼bMechanical Engineering and Applied Mechanics.
■7730 ▼tDissertations Abstracts International▼g85-12B.
■790 ▼a0175
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17161156▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
