Characterization of Laminar-Turbulent transition in a plane Couette flow due to stable stratification using CFD
Despite recent advances in understanding the physical capacity of the thermal and mechanical parameters that control or isolate the nocturnal boundary layer, these are not yet fully understood. The emergence of natural intermittence in runoff is also not a consensus in the boundary layer scientific...
| Authors: | , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2020 |
| Country: | Brasil |
| Institution: | Universidade Federal de Santa Maria (UFSM) |
| Repository: | Revista Ciência e Natura (Online) |
| Language: | Portuguese |
| OAI Identifier: | oai:ojs.pkp.sfu.ca:article/45341 |
| Online Access: | https://periodicos.ufsm.br/cienciaenatura/article/view/45341 |
| Access Level: | Open access |
| Keyword: | Large Eddy Simulation Intermittency Stable Boundary Layer Laminar-Turbulent Transition Simulação de Grandes Turbilhões Intermitência Camada Limite Estável Transição Laminar-Turbulenta |
| Summary: | Despite recent advances in understanding the physical capacity of the thermal and mechanical parameters that control or isolate the nocturnal boundary layer, these are not yet fully understood. The emergence of natural intermittence in runoff is also not a consensus in the boundary layer scientific community. Many of the studies that present numerical studies on intermittence make use of external flow, forcing that is responsible for the resurgence of turbulence. Thus, the current proposal aims to develop a numerical experiment to study the laminar-turbulent transition using computational fluid dynamics. In this case, the thermal stratification will be applied to a turbulent flow entirely generated to obtain conditions of robust stability and to reproduce an intermittent flow. The results show that when the flow regime is thoroughly turbulent, all levels are coupled by turbulence, making speed and temperature fields more homogeneous in the center of the domain. The results show that when the flow regime is completely turbulent, all levels are coupled by turbulence, making speed and temperature fields more homogeneous in the center of the domain. As a temperature gradient is introduced into the flow, the vertical levels become uncoupled, and under very stable conditions, the turbulence is wholly suppressed. While the distinction between flow regimes is evident, the transition between flow regimes occurs intermittently. |
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