The effect of the finite extent of a linear cascade on the acoustic and vortical modes generated at the cascade exit by a set of moving bars located at the inlet is assessed by means of a numerical study. The sidewall interference is studied for an airfoil, which is representative of the midsection of a low pressure turbine airfoil. The deviations from the purely periodic steady state have been also investigated. It is concluded that both the unsteady pressure distributions on the airfoil and the mode-decomposition at the cascade exit show a reasonable matching with the purely periodic case, provided that the nominal interblade phase angle is taken into account to postprocess the numerical data. This conclusion is a key element to the investigation of the scattering and propagation of pure tones in turbomachinery in high speed linear cascades.

Issue Section:
Research Papers
Keywords:
aerodynamics, blades, numerical analysis, turbomachinery, vortices
Topics:
Airfoils, Cascades (Fluid dynamics), Flow (Dynamics), Pressure
1.
Schulte
,
V.
, and
Hodson
,
H. P.
, 1994, “
Wake-Separation Bubble Interaction in Low Pressure Turbines
,” presented at the
AIAA/ASME/SAE/ASEE Joint Propulsion Conference
, Indianapolis, IN, Jun. 27–29.
2.
Dong
,
Y.
, and
Cumpsty
,
N. A.
, 1990, “
Compressor Blade Boundary Layers: Part II—Measurements With Incident Wakes
,”
ASME J. Turbomach.
0889-504X,
112
, pp.
231
–
240
.
Crossref
Search ADS
 
3.
Buffum
,
D. H.
, and
Fleeter
,
S.
, 1991, “
Linear Oscillating Cascade Unsteady Aerodynamic Experiments
,”
Sixth International Symposium on Unsteady Aerodynamics, Aeroelasticity and Aeroacoustics of Turbomachines
,
Atassi
, ed., Sept. 15–19.
4.
Chima
,
R. V.
,
McFarland
,
E. R.
,
Wood
,
J. R.
, and
Lepicovsky
,
J.
, 2000, “
On Flowfield Periodicity in the NASA Transonic Flutter Cascade, Part II—Numerical Study
,” ASME Paper No. 2000-GT-0573.
5.
Lepicovsky
,
J.
,
McFarland
,
E. R.
,
Chima
,
R. V.
,
Wood
,
J. R.
, 2000, “
On Flowfield Periodicity in the NASA Transonic Flutter Cascade, Part I—Experimental Study
,” ASME Paper No. 2000-GT-0572.
6.
Ott
,
P.
,
Norryd
,
M.
, and
Bölcs
,
A.
, 1998, “
The Influence of Tailboards on Unsteady Measurements in a Linear Cascade
,” ASME Paper No. 98-GT-0572.
7.
Corral
,
R.
, and
Gisbert
,
F.
, 2003, “
A Numerical Investigation on the Influence of Lateral Boundaries in Linear Vibrating Cascades
,”
ASME J. Turbomach.
0889-504X,
125
, pp.
433
–
441
.
Crossref
Search ADS
 
8.
Corral
,
R.
,
Escribano
,
A.
,
Gisbert
,
F.
,
Serrano
,
A.
, and
Vasco
,
C.
, 2003, “
Validation of a Linear Multigrid Accelerated Unstructured Navier–Stokes Solver for the Computation of Turbine Blades on Hybrid Grids
,” AIAA Paper No. 2003-3326.
9.
Corral
,
R.
,
Crespo
,
J.
, and
Gisbert
,
F.
, 2004, “
Parallel Multigrid Unstructured Method for the Solution of the Navier–Stokes Equations
,” AIAA Paper No. 2004-0761.
10.
Jameson
,
A.
,
Schmidt
,
W.
, and
Turkel
,
E.
, 1981, “
Numerical Solution of the Euler Equations by Finite Volume Techniques Using Runge–Kutta Time Stepping Schemes
,” AIAA Paper No. 1981-1259.
11.
Roe
,
P.
, 1981, “
Approximate Riemann Solvers, Parameters, Vectors and Difference Schemes
,”
J. Comput. Phys.
0021-9991,
43
, pp.
357
–
372
.
Crossref
Search ADS
 
12.
Swanson
,
R. C.
, and
Turkel
,
E.
, 1992, “
On Central-Difference and Upwinding Schemes
,”
J. Comput. Phys.
0021-9991,
101
, pp.
292
–
306
.
Crossref
Search ADS
 
13.
Corral
,
R.
,
Burgos
,
M. A.
, and
García
,
A.
, 2000, “
Influence of the Artificial Dissipation Model on the Propagation of Acoustic and Entropy Waves
,” ASME Paper No. 2000-GT-563.
14.
Giles
,
M. B.
, 1990, “
Non-Reflecting Boundary Conditions for Euler Equation Calculations
,”
AIAA J.
0001-1452,
28
(
12
), pp.
2050
–
2057
.
Crossref
Search ADS
 
15.
Tyler
,
J. M.
, and
Sofrin
,
T. G.
, 1962, “
Axial Flow Compressor Noise Studies
,”
SAE Trans.
0096-736X,
70
, pp.
309
–
332
.
16.
Vera
,
M.
,
Hodson
,
H. P.
, and
Vazquez
,
R.
, 2004, “
The Effects of a Trip Wire and Unsteadiness on a High Speed Highly Loaded Low Pressure Turbine Blade
,” ASME Paper No. 20004-GT-53822.
17.
Whitehead
,
D. S.
, 1987, “
Classical Two-Dimensional Methods
,”
AGARD Manual on Aeroelasticity in Axial Flow Turbomachines: Unsteady Turbomachinery Aerodynamics
, Vol.
1
,
M. F.
Platzer
 and
F. O.
Carta
, eds., Chap. 2, Paper No. AGARD-AG-298.
18.
Gómez
,
A.
,
Serrano
,
A.
, and
de la Calzada
,
P.
, 2003, “
Investigation on Numerical and Geometry Modelling Effects on the CFD Simulation of Interaction Noise in LP Turbines
,”
Proceedings of the 5th European Conference on Turbomachinery
,
M.
Stastny
,
C. H.
Sieverding
, and
G.
Bois
, eds., Praha, Czech, Mar. 17–22, pp.
25
–
36
.
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 by American Society of Mechanical Engineers
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