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Memorias de investigación
Artículos en revistas:
Influence of flow tree-dimensionality on the heat transfer of a narrow channel backward facing step flows
Año:2018
Áreas de investigación
  • Ingeniería mecánica, aeronaútica y naval
Datos
Descripción
This manuscript studies the forced-mixed convective flow on a three-dimensional backward facing step with low aspect ratio (AR=4) and expansion ratio ER=2 for Reynolds number in the laminar and beginning of transitional regime (Re 100?1200). The analysis is performed using large eddy simulations, with the main objective assessing the effect of sidewalls on heat transfer characteristics on bottom wall in narrow channels with sudden expansion. The numerical model has been validated with experimental and numerical results from the literature and qualitatively with the experimental results obtained through Moiré deflectometry. The bottom surface was kept at constant temperature greater than the flow inlet temperature, while the other walls are considered to be adiabatic. To decouple the three-dimensional flow features due to the sidewalls and the intrinsic three-dimensional instabilities of the separated flow, two different boundary conditions on lateral walls, slip and non-slip, have been used. The results obtained show that when slip sidewalls are considered, the three-dimensional intrinsic structures begging to appear for Re equal to 1200. These structures enhance the heat transfer in the bottom wall. On the contrary, with non-slip sidewalls, the strong three-dimensional structures caused by the sidewalls represented by the upper side recirculation bubble and the wall jets mask the intrinsic three-dimensional instability, decreasing the heat transfer in the lower wall downstream of the step. As a consequence, the surface averaged Nusselt for all Reynolds numbers corresponding to the beginning of the transitional flow is lower for the case of non-slip sidewalls than for the case of slip sidewalls. Thus, the study concludes that sidewalls have a negative effect on heat transfer in narrow channels for flow Reynolds numbers in the early transitional regime.
Internacional
Si
JCR del ISI
Si
Título de la revista
International Journal of Thermal Sciences
ISSN
1290-0729
Factor de impacto JCR
3,361
Información de impacto
Datos JCR del año 2017
Volumen
132
DOI
10.1016/j.ijthermalsci.2018.06.005
Número de revista
Desde la página
234
Hasta la página
248
Mes
SIN MES
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Participantes
  • Autor: Gregorio Lopez Juste (UPM)
  • Autor: Pablo Fajardo (Universidad Carlos III de Madrid)
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Departamento: Mecánica de Fluidos y Propulsión Aeroespacial
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