Profile losses of the turbine blade and secondary flow losses
are the main source of aerodynamic loss in a low pressure turbine.
However, not much attention has been paid in the interaction
between these two loss sources. This paper investigates the
interaction mechanisms between a separated boundary layer on
the suction side and the secondary flow in blade passages.
The high speed cascade wind tunnel of the University of the
Federal Armed Forces Germany has been used to achieve the
required operation conditions, generating a flow separation on
the suction side. The profile of this cascade has been chosen due
to the flow separation behavior on the suction side of the blade at
low Reynolds numbers. Different measurements techniques are
conducted to further investigate the effects seen in CFD.
The aim of this paper is to investigate the interaction phenomena
between the secondary flow and a separation bubble at
different Reynolds numbers. The development and change of the
boundary layer in the axial and radial directions on the suction
side of the turbine blade are presented and discussed. The results
show discrepancies between the numerical prediction and the experimental
data on the suction side of the blade rise as the effects
of the secondary flow increase. Furthermore, the increasing influence
of the radial pressure gradient of the secondary flow leads
to a noticeable reduction in the length of the separation bubble
close to the endwall region.
«Profile losses of the turbine blade and secondary flow losses
are the main source of aerodynamic loss in a low pressure turbine.
However, not much attention has been paid in the interaction
between these two loss sources. This paper investigates the
interaction mechanisms between a separated boundary layer on
the suction side and the secondary flow in blade passages.
The high speed cascade wind tunnel of the University of the
Federal Armed Forces Germany has been used to achieve th...
»