A two-dimensional time-accurate Navier-Stokes solver for incompressible flows is used to simulate the effects of the axial spacing between an upstream rotor and a stator, and the wake/blade count ratio on turbomachinery unsteady flows. The code uses a pressure-based method. A low-Reynolds number two-equation turbulence model is incorporated to account for the turbulence effect. By computing cases with different spacing between an upstream rotor wake and a stator, the effect of the spacing is simulated. Wake/blade count ratio effect is simulated by varying the number of rotor wakes in one stator passage at the computational inlet plane. Results on surface pressure, unsteady velocity vectors, blade boundary layer profiles, rotor wake decay and loss coefficient for all the cases are interpreted. It is found that the unsteadiness in the stator blade passage increases with a decrease in the blade row spacing and a decrease in the wake/blade count ratio. The reduced frequency effect is dominant in the wake/blade count ratio simulation. The time averaged loss coefficient increases with a decrease in the axial blade row spacing and an increase in the wake/blade count ratio.

Issue Section:
Research Papers
Topics:
Blades, Computer simulation, Rotors, Stators, Turbomachinery, Unsteady flow, Wakes, Pressure, Turbulence, Boundary layers, Flow (Dynamics), Simulation
1.
Basson
A. H.
, and
Lakshminarayana
B.
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1994
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2.
Chien
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,
1982
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3.
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4.
Gallus
H. E.
,
Grollius
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, and
Lambertz
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,
1982
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The Influence of Blade Number Ratio and Blade Row Spacing on Axial-Flow Compressor Stator Blade Dynamic Load and Stage Sound Pressure Level
,”
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633
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5.
Giles
M. B.
,
1990
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Stator-Rotor Interaction in a Transonic Turbine
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6.
Ho. Y.-H., and Lakshminarayana, B., 1995, “Computation of Unsteady Viscous Flow Through Turbomachinery Blade Row Due to Upstream Rotor Wakes,” ASME Journal of Turbomachinery, Vol. 117, Oct.
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M. M.
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,”
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9.
Stauter
R. D.
,
Dring
R. P.
and
Carta
F. O.
,
1991
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Temporally and Spatially Resolved Flow in a Two-Stage Axial Compressor, Part 1: Experiment
,”
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10.
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11.
Yu, W.-S., 1996, “Numerical Simulation of 3D Unsteady Turbulent Flows through Turbomachinery including Rotor-Stator Interaction,” PhD thesis (in preparation), The Pennsylvania State University.
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