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Abstract

With use, new turbine blades experience a change in profile and surface roughness. An experimental study has been carried out in rectilinear cascades of reaction and impulse blades with smooth and rough surfaces. The roughnesses of 220, 100, and 50 grades emery paper, one at a time, is applied over suction and pressure surfaces at one-third of surface at leading edge, mid-chord and trailing edge regions. Measurement of pressure, exit angle, and velocity at exit of the cascade has been taken with a three-hole probe. It has been observed that the same roughness at mid-chord of suction surface is most detrimental and least detrimental when applied at mid-chord of pressure surface. It has also been seen that the same roughness over impulse blade is more detrimental than that over reaction blade.

Keywords

roughness turbine blade loss coefficient steam turbine exit angle reaction turbine impulse turbine cascade

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References

Samsher

Rai L.

Kale

S. R.

Effect of blade surface roughness on the performance of steam turbines. Proceedings International Conference on Fluid mechanics and fluid power, IIT, Delhi, India, 1998, 376–384.

Samsher

Effect of blade surface roughness on profile loss and exit angle in a rectilinear steam turbine cascade. PhD Thesis, IIT, Delhi, India, 2002.

Forster

V. T.

Performance loss of modern steam-turbine plant due to surface roughness. Proc. Instn Mech. Engrs, 181, 1966–67, 391–422.

Kind

R. J.

Serjak

P. J.

Abbott

M. W. P.

Measurements and prediction of the effects of surface roughness on profile losses and deviation in a turbine cascade. Proceedings 1996 International Gas Turbine and Aeroengine Congress and Exhibition, Birmingham, UK, 10–13, June, 1996.

Roelke

R. J.

Haas

J. E.

The effect of rotor blade thickness and surface finish on the performance of a small axial flow turbine. ASME J. Eng. for Power, 1983, 105, 377–382.

Bryer

D. W.

Pankhurst

R. C.

Pressure-probe methods for determining wind speed and flow direction. National Physical Laboratory, Department of Trade and Industry, London, 1971.

Blevins

R. D.

Applied fluid dynamics handbook, 1984, 264–272. (Van Nastrand Reinhold, New York).

Deich

M. E.

Filippov

G. A.

Lazarev

L. V.

Atlas of profiles for axial flow turbine cascades (in Russian), 1965 (Mashinostroenie, Moscow).

Kline

S. J.

The purpose of uncertainty analysis. J. Fluids Eng., 107, 1985, 153–160.

10.

Gostelow

J. P.

Cascade aerodynamics, 1984 (Pergamon, Oxford, UK).

Effects of localized roughness over reaction and impulse blades on loss coefficient

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