The three-dimensional effects of secondary flow, passive injection, and particle size on the motion of solid particles entrained in a laminar, incompressible flow through a curved, converging, rectangular passage were numerically investigated. Emphasis was placed on observing the physical mechanisms that cause particles 5 μm and smaller in diameter to deposit on passage surfaces and to concentrate near the endwalls and mid-span at the passage exit. Particle trajectories were calculated for 5, 30, and 300 μm diameter solid particles. It was observed that the paths of 5 μm particles were similar to the streamlines of the three-dimensional flow in the channel until the particles encountered the boundary layers on the blade surfaces and endwalls, where they would graze the surfaces (contributing to particle deposition) and concentrate at the exit of the channel. Particles of 30 μm diameter, however, were only slightly affected by secondary flows, but were affected enough to be made to concentrate at the exit near the endwall and mid-span surfaces. Particles of 300 μm diameter were not affected by secondary flows at all. The particle trajectories showed that the passage secondary flow convected particles across endwalls toward the pressure and suction surface boundary layers of the blades. It was observed that small particles were made to decelerate and/or concentrate in the boundary layers near the passage exit. It was found that this concentration of particles along the suction surface and endwalls could be significantly reduced by means of passive injection. (Passive injection is a method of inducing the flow of jets in the curved portion of an airfoil shaped surface due to the pressure difference on opposing sides. This is accomplished by means of holes or slots that have been drilled through the surface at strategic locations.)

1.
Azim, A. F., Abdel, and Rouleau, W. T., 1983, “Secondary Flow Effect on Erosion Damage of a Stationary Cascade,” 6th International Conference on Erosion by Liquid and Solid Impacts (ELSI VI), Cambridge University, Sept.
2.
Ekerle
W. A.
, and
Langston
L. S.
,
1987
, “
Horseshoe Vortex Formation Around a Cylinder
,”
ASME Journal of Engineering for Gas Turbines and Power
, Vol.
109
, Apr., pp.
278
284
.
3.
El-Sayed, A. F., Lasser, R., and Rouleau, W. T., 1986, “Effects of Secondary Flow on Particle Motion and Erosion in a Stationary Cascade,” International Journal of Heat and Fluid Flow, Vol. 7, No. 2, June.
4.
Finnie
I.
, and
Kabil
Y. H.
,
1968
, “
On the Formation of Surface Ripples During Erosion
,”
Wear
, Vol.
8
, pp.
5
21
.
5.
Grant, George K., 1973, “A Model to Predict Erosion in Turbomachinery Due to Solid Particles in a Particulated Flow,” UMI Dissertation Services, Apr.
6.
Hah
C.
,
1984
, “
A Navier Stokes Analysis of Three-Dimensional, Turbulent Flows Inside Turbine Blade Rows at Design and Off-Design Conditions
,”
ASME Journal of Engineering for Gas Turbines and Power
, Vol.
106
, Apr., pp.
421
428
.
7.
Hamed, A., and Kuhn, T. P., 1993, “Effects of Variational Particle Restitution Characteristics on Turbomachinery Erosion,” International Gas Turbine and Aeroengine Congress and Exposition, Cincinnati, Ohio, May.
8.
Kawai
T.
,
Hinoki
S.
, and
Adachi
T.
,
1989
, “
Secondary Flow Control and Loss Reduction in a Turbine Cascade Using Endwall Fences
,”
JSME International Journal
, Series II, Vol.
32
, No.
3
, pp.
375
385
.
9.
Kladas
D. D.
, and
Georgiou
D. P.
,
1993
, “
A Relative Examination of CD – Re Relationships Used in Particle Trajectory Calculations
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
115
, Mar., pp.
162
165
.
10.
Kozlu, H., Louis, and Jean, F., 1987, “Particle Transport Across the Transpired Turbulent Boundary Layer,” Gas Turbine Conference and Exhibition, Anaheim, CA, May.
11.
Lasser, R., 1982, “The Effects of Secondary Flows in an Arbitrarily Curved Blade Passage of Converging Cross Section and in the Wake Downstream of a Cascade of Airfoils,” Ph.D. dissertation, Carnegie Mellon University.
12.
Madden, M., 1984, “Secondary Flow Control by Passive Injection,” Master’s thesis, Carnegie Mellon University.
13.
Putnam, A. A., et al., 1957, “Injection and Combustion of Liquid Fuels,” WADC TR 56-344, Batelle Memorial Institute, Mar.
14.
Soo, S. L., 1967, Fluid Dynamics of Multiphase Systems, Blaisdell Publishing, Waltham, MA.
15.
Tal, R., Lee, D. N., and Rouleau, W. T., 1982, “Secondary Flow Control by Passive Injection,” Internal Report, Mechanical Engineering Department, Carnegie Mellon University.
16.
Ulke, A., 1975, “An Approximate Analysis of the Effect of Secondary Flows on the Motion of Particulates in an Axial Flow Gas Turbine,” Ph.D. dissertation, Carnegie Mellon University.
17.
Ulke, A., and Rouleau, W. T., 1976, “The Effects of Secondary Flow on Turbine Blade Erosion,” ASME Paper No. 76-GT-74.
18.
Ventresca, James J., 1994, The Effects of Secondary Flow and Passive Injection on the Motion of Solid Particles Through a Curved Converging Channel, Ph.D. dissertation, Carnegie Mellon University.
19.
Wenglarz, Richard A., 1987, “Turbine Deposition, Erosion and Corrosion Evaluations Using a Simplified Test Approach,” Gas Turbine Conference and Exhibition, Anaheim, CA, May.
This content is only available via PDF.
You do not currently have access to this content.