A centrifugal compressor discharge pressure and temperature

A centrifugal compressor discharge pressure and temperature are measured to be P_13 = 303 kPa T_13 = 408 K The inlet flow is purely axial with C_z1 = 100 m/s and the inlet total pressure and temperature are P_11 = 101 kPa T_I = 288 K Calculate (a) total-to-static pressure ratio. (b) total-to-total pressure ratio (c) total-to-static adiabatic efficiency (d) total-to-total adiabatic efficiency (e) polytropic efficiency e_c for total-static and total-total processes

Solution

P1 = 101 kpa

T1= 288 k

P2= 303 kpa

T2= 408 k

Inlet flow velocity C =100 m/s

Static pressure= V2/2g= 100 x 100/ 2 x 9.81= 510 m = 51 bar= 5100 kpa =

1. Total to static pressur ratio= 5100/300= 16

2. Total to total pressure ratio = 303 /101 = 3