Gas-Turbine Powerplants For Two-Phase Hydropropulsion 



2^ 



U9 



07 



Q5 



I. i i n 2 3 i 6 a n 2 3 i 6 » lo 



(c) M^ as a function of e ( 4; = 0.9, 

 (3 = IZ, a. p.) 



Fig. 32 - IR-FC powerplant 

 performances —Cont'd. 



pressures that can be reached by the turbine mean pressure are somewhat low. 

 On the contrary, good performance can be obtained by the configuration IB- (2) 

 (Fig. 35); the efficiency is very high (up to 0.2) and no speed limits were found 

 up to 50 m/s. Higher exit pseudo-Mach numbers are required at higher /3p, 

 because of the shifting in the maxima. No solutions at the highest speed can 

 be obtained at fi^ > 3, because of the exceedingly high chamber pressure com- 

 patibility with the turbine pressure ratio /? = 12. 



In Fig. (41) the maximum speed V„ ^^^ which can be obtained at 

 variable /Sp and at fixed fi is shown. This diagram indicates the operative 

 fall of a turbine-fed system; it can be used for any powerplant, and /3 must 

 represent the lowest pressure (that is, /3^ in IR-(2) and IB- (2) plants). 



It appears that, with a (/3 = 12)-turbine, a speed not higher than 

 54 m/s at /3 = 2 and not higher than 37.5 m/s at /3 = 4 can be achieved. 



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