27:7%. With the input power unchanged, the output power increases from 4:97 kW
at 6000 r=min to 5:88 kW.
Of course, the increase of rotational speed is limited by the strength and other
factors, so the strength of the turbine disk, the critical speed of the rotating shaft, the
bearing capacity, and accuracy of the bearing must be considered comprehensively.
It can be seen from the characteristic ratio k ¼ u=c 1 that in addition to increasing
the rotational speed and increasing the circumferential velocity u accordingly to
achieve the optimal characteristic ratio, reducing c 1 can also be adopted, i.e., reducing
Turbine input power/kw
Turbine rotational speed/(r/min)
Fig. 9.47 Turbine output
power varies with rotational
speed at a given input power
Table 9.14 Wheel circumferential work, effective work, and losses of working fluid per kg at
turbine rotational speed 97000 r/min
(J/kg)
Percentage of total
input work (%)
Remarks
VPUN = 169190.4
11.63288
Nozzle work loss
VY = 255488.4
17.56296
Blade work loss
VYU = 255932
17.5969
Residual kinetic energy work loss
VLOU = 38632.47
2.656219
Leakage work loss
VLT = 27225.96
1.871952
Wheel disk friction blast work loss
VLQ = 278751
19.16584
Partial intake work loss
VLM = 25682.38
1.765821
Mechanical work loss
LE = 402357.3
27.66453
Effective work, percentage, effective
efficiency turbine input total work
N = 97,000 r/min
Turbine design speed
N e ¼ 5:883 149 kW
Turbine output power
9.4 Design Principle of Small Gas Turbine for Missile
143