The effect of boundary layer fluctuations on the streamwise vortex structure in simulated plane turbulent mixing layers
| Autor: | W. A. McMullan |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics business.industry Turbulence Mechanical Engineering Boundary layer control Laminar flow Mechanics Condensed Matter Physics Boundary layer thickness 01 natural sciences 010305 fluids & plasmas Physics::Fluid Dynamics Flow separation Boundary layer Optics 0103 physical sciences 010306 general physics business Mixing (physics) Large eddy simulation |
| Zdroj: | International Journal of Heat and Fluid Flow. 68:87-101 |
| ISSN: | 0142-727X |
| DOI: | 10.1016/j.ijheatfluidflow.2017.08.015 |
| Popis: | This paper details the influence of the magnitude of imposed inflow fluctuations on Large Eddy Simulations of a spatially developing turbulent mixing layer originating from laminar boundary layers. The fluctuations are physically-correlated, and produced by an inflow generation technique. The imposed high-speed side boundary layer fluctuation magnitude is varied from a low-level, up to a magnitude sufficiently high that the boundary layer can be considered, in a mean sense, as nominally laminar. Cross-plane flow visualisation shows that each simulation contains streamwise vortices in the laminar and turbulent regions of the mixing layer. Statistical analysis of the secondary shear stress reveals that mixing layers originating from boundary layers with low-level fluctuations contain a spatially stationary streamwise structure. Increasing the high-speed side boundary layer fluctuation magnitude leads to a weakening of this stationary streamwise structure, or its removal from the flow entirely. The mixing layer growth rate reduces with increasing initial fluctuation level. These findings are discussed in terms of the available experimental data on mixing layers, and recommendations for both future experimental and numerical research into the mixing layer are made. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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