"EXAMPLE: Air-standard Brayton cycle
 
An air-standard Brayton cycle operates under the following conditions: compressor inlet:
100 kPa, 300 K; turbine inlet, 1 MPa, 1300 K.
 
(a) Find the heat transfer rate and power (per unit mass flow rate) for each device in the cycle.
(b) Find the cycle efficiency.
(c) What is the pressure ratio for the cycle?"
 
T_1 = 300 [K]
P_1 = 100 [kPa]
 
P_3 = 1000 [kPa]
T_3 = 1300 [K]
 
"CoE, (1)-->(2)"
w_12_in = h_2 - h_1
h_1 = enthalpy(Air,T=T_1)
s_1 = entropy(Air,T=T_1,P=P_1)
P_2 = P_3
s_2 = s_1
h_2 = enthalpy(Air,P=P_2,s=s_2)
 
"CoE, (2)-->(3)"
q_23_in = h_3 - h_2
h_3 = enthalpy(Air,T=T_3)
 
"CoE, (3)-->(4)"
w_34_out = h_3 - h_4
s_3 = entropy(Air,T=T_3,P=P_3)
P_4 = P_1
s_4 = s_3
h_4 = enthalpy(Air,P=P_4,s=s_4)
 
"CoE, (4)-->(1)"
q_41_out = h_4 - h_1
 
"Cycle effficiency"
eta = (w_34_out-w_12_in)/q_23_in