Fluid Mechanics and Thermodynamics of Turbomachinery, 5e

Measured performance
Radial Flow Gas Turbines 285
Figures 8.22 and 8.23 show the effect of the setting angle of the outer guide vanes
on the efficiency of the turbine under steady flow conditions. In Figure 8.22 the flow
is from the settling chamber to atmosphere (exhaling flow) and shows the efficiency vs
the flow coefficient, j for qi = 25° and q o = 15, 20, 25 and 30°. The maximum efficiency
obtained was 33% at j = 0.83 with qo = 30°. Similarly, in Figure 8.23, the inhaling
steady flow efficiency vs j again is for qi = 25° and qo = 15, 20, 25 and 30°. For
this flow direction the maximum efficiency was just over 35% at j = 0.6 with qo = 15°.
References
h
0.4
0.3
0.2
0.1
0
0.5
1.0
Flow coefficient, j
From atmosphere
Abidat, M., Chen, H., Baines, N. C. and Firth, M. R. (1992). Design of a highly loaded mixed
flow turbine. J. Power and Energy, Proc. Instn. Mech. Engrs., 206, 95–107.
Anon. (1971). Conceptual design study of a nuclear Brayton turboalternator-compressor.
Contractor Report, General Electric Company. NASA CR-113925.
Balje, O. E. (1981). Turbomachines—A guide to Design, Selection and Theory. Wiley.
Benson, R. S. (1970). A review of methods for assessing loss coefficients in radial gas turbines.
Int. J. Mech. Sci., 12.
Benson, R. S., Cartwright, W. G. and Das, S. K. (1968). An investigation of the losses in the
rotor of a radial flow gas turbine at zero incidence under conditions of steady flow. Proc. Instn.
Mech. Engrs. London, 182, Pt 3H.
Fullagar, K. P. L. (1973). The design of air cooled turbine rotor blades. Symposium on Design
and Calculation of Constructions Subject to High Temperature, University of Delft.
1.5
q i
q 0
25° 15°
25° 20°
25° 25°
25° 30°
2.0 2.5
FIG. 8.23. Measured efficiency under steady flow conditions from atmosphere for the
radial flow turbine. (From Setoguchi et al. 2002, by permission of the Council of the
Institution of Mechanical Engineers.)