Question

A gas turbine tested with air passed 15kgs when the expansion ratio was 1.6:1, the rotational speed was 6000 rpm, and the inlet static con- ditions were 10 X 10*Nm and 288 K. The same machine when used for its designed purpose was supplied with combustion products at the inlet conditions of 11 X 10PNm and 660 K 1f the expansion ratio was also 1.6:1, estimate for dynamically similar conditions the rotational speed and mass flow rate (For combustion products R= 2291 Jkg-K .)

Answer 1

Given that:

A gas turbine tested with air passed 15 kg s^-1 when expression ratio was 1.6:1

rotational speed was 6000 rpm

inlet static condition were 10*10 N m^-2 and 288 k

combustion products at the inlet conditions of 1.4 *10^6 N m^-2 and 660 L

the expansion ratio was 1.6:1

R=2291 J Kg^-1 K^-1
Answert calculate the mass flow rate of model, Po, D a constant. in WRTo, m 2 ORTOR P.02. : 0,5 15x W288 ming 660 = loxio y - 1-4X105 (5x:16.970 M2185.690) 1400000 100000 25.455 mg (25.670) 100000 1400000 ») 0.00025455 = trg (25.690) 1400000 - m (25.690) - 1400000X 0.00025455 mg (25.690) = 356.37, mg = 356.37 = 138.72. kgls.

mig = 138-72 kg Is. calculate the speed of model, N, D a constant : VRTO, ND N D 6000 | 6000 Ne | 288 . √660 6000 No = 16.970 25.690 -) 353.56 = N2 25.690 My = 25.690x 353-56. [ Ng = 9682.95 opm]