Visualization study and quantitative velocity measurements in turbulent taylor-couette flow by phantomm flow tagging: a description of the transition to turbulence



Título del documento: Visualization study and quantitative velocity measurements in turbulent taylor-couette flow by phantomm flow tagging: a description of the transition to turbulence
Revista: Journal of the Brazilian Society of Mechanical Sciences and Engineering
Base de datos: PERIÓDICA
Número de sistema: 000312172
ISSN: 1678-5878
Autores: 1
2
Instituciones: 1Universidade Federal de Uberlandia, Escola de Engenharia Mecanica, Uberlandia, Minas Gerais. Brasil
2Faculdade Politecnica de Uberlandia, Uberlandia, Minas Gerais. Brasil
Año:
Periodo: Oct-Dic
Volumen: 25
Número: 4
Paginación: 378-390
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental
Resumen en inglés A visualization study and Quantitative velocity measurements have been performed in Taylor-Couette flow with a medium-gap (ç= 0.356), over a large range of Taylor numbers (2.1x10(4) < Ta < 1.1x10(11)), with the outer cylinder fixed and the inner cylinder rotating about its axis. Quantitative velocity measurements were carried out using the PHANTOMM flow tagging technique. Two techniques were used for visualization study: the PHANTOMM technique that allowed flow structure visualization from small to moderate Taylor numbers, and the Particle Streak Imaging, PSI (the flow was seeded with neutrally buoyant polystyrene micro spheres) that permitted the flow structure visualization from moderate to high Taylor numbers. The results illustrate the expected three-dimensional features of flow and presence of Taylor cells at low Taylor numbers. Our study examined the interplay between small and large scales present in the flow as well as showed the gradual transition to turbulence with increasing Taylor numbers. Taylor cells were found for Taylor numbers less than 1.13 x 10(10). At low Taylor numbers, the flow in the cells appeared to be a rotational laminar flow with a high degree of coherence. At higher Taylor numbers, the cells aspect became more irregular, and the flow inside them became turbulent. The Görtler instability developed inside Taylor cells and close to the inner cylinder wall. At the highest Taylor numbers, turbulence increased up to the point where no Taylor cells could be detected. For the flow in our study, at Ta = 1
Disciplinas: Física y astronomía
Palabras clave: Dinámica de fluidos,
Flujo Taylor-Couette,
Turbulencia,
Transición,
Visualización,
Velocidad,
Medición
Keyword: Physics and astronomy,
Fluid dynamics,
Taylor-Couette flow,
Turbulence,
Transition,
Visualization,
Velocity,
Measurement
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