Abstract (EN):
An experimental investigation was carried out to characterize the flow field in a liquid impinging
jet confined by slopping plane walls and emanating from a rectangular duct. The fluids are Newtonian
flowing in the laminar (Re= 135 and 276) and turbulent regimes (Re=13,750) and the two-dimensional
rectangular cell has an aspect-ratio equal to 13. The fully-developed rectangular jet impinging the flat surface
(plate) is confined by two slopping plane walls, each one making an angle of 12° relative to the plate. The
presence of the impact plate is felt upstream at y/H= -0.2 in the laminar regime and at y/H= -0.4 in the
turbulent regime. The results show that the flow is symmetric relative to the x-y and x-z center planes. Near
the plane slopping wall there is separated flow for Reynolds numbers in excess of 208, as was observed in
visualization studies. For Re= 275 this small separated flow zone has a normalized length, xR/H = 0.25,
whereas for turbulent flow xR/H is equal to 0.9. In the turbulent flow regime turbulence is very high at the jet
impact region due to strong fluid deceleration, but the maximum turbulence is observed in the shear layer
formed between the jet along the impinging wall and the separated flow region on the sloping wall. We also
report three-dimensional effects due to finite slenderness of the flow geometry.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
13
Tipo de Licença: