The three dimensional structures of the blade tip vortical flow field is discussed for a family of axial fans in fully-ducted configuration, to investigate an improved blade tip concept. This concept is based on geometrical modification of datum blade by means of profiled end-plates at the tip. The investigation has been carried-out using an accurate in-house developed multilevel parallel finite element RANS solver, with the adoption of a non-isotropic two-equation turbulence closure. Due to the fullyducted configuration, the fans have a complex vortical flow field near the rotor tip. The nature of the flow mechanisms in the fan tip region is correlated to the specific blade design features that promote reduced aerodynamic noise. It was found that the tip geometrical modification markedly affects the multiple vortex leakage flow behaviour, by reducing the pressure difference within the tip gap and by altering the near-wall fluid flow paths on the blade surfaces. The rotor loss behaviour, in the blade tip region, was also discussed in order to assess the effect of blade tip geometry onto the rotor efficiency. Copyright © 2006 by ASME.
Investigation on improved blade tip concept for axial flow fan / CORSINI, Alessandro; B., PERUGINI; RISPOLI, Franco; A. G., SHEARD; I., KINGHORN. - ELETTRONICO. - 6 PART A:(2006), pp. 313-325. (Intervento presentato al convegno 2006 ASME 51st Turbo Expo tenutosi a Barcelona; Spain nel May 2006) [10.1115/GT2006-90592].
Investigation on improved blade tip concept for axial flow fan
CORSINI, Alessandro;RISPOLI, Franco;
2006
Abstract
The three dimensional structures of the blade tip vortical flow field is discussed for a family of axial fans in fully-ducted configuration, to investigate an improved blade tip concept. This concept is based on geometrical modification of datum blade by means of profiled end-plates at the tip. The investigation has been carried-out using an accurate in-house developed multilevel parallel finite element RANS solver, with the adoption of a non-isotropic two-equation turbulence closure. Due to the fullyducted configuration, the fans have a complex vortical flow field near the rotor tip. The nature of the flow mechanisms in the fan tip region is correlated to the specific blade design features that promote reduced aerodynamic noise. It was found that the tip geometrical modification markedly affects the multiple vortex leakage flow behaviour, by reducing the pressure difference within the tip gap and by altering the near-wall fluid flow paths on the blade surfaces. The rotor loss behaviour, in the blade tip region, was also discussed in order to assess the effect of blade tip geometry onto the rotor efficiency. Copyright © 2006 by ASME.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
