"Isothermal boundary work for ideal gas" W_b = m R T ln(v2/v1) "Negative if compressed" "Alternatively:" W_b = m R T ln(P1/P2)
"Isentropic expansion" s2 = s1 h2s = enthalpy(Fluid$, P=P2, s=s2) T2s = temperature(Fluid$, P=P2, s=s2) x2s = quality(Fluid$, P=P2, s=s2) "If in two-phase" Engineering Equation Solver EES Cengel Thermo Iso
"Isentropic turbine work" W_s = h1 - h2s "kJ/kg" "Isothermal boundary work for ideal gas" W_b =
"Actual (given efficiency η=0.85)" η = 0.85 η = (h1 - h2a)/(h1 - h2s) h2a = h1 - η*(h1 - h2s) W_a = h1 - h2a EES replaces table lookup: s=s2) T2s = temperature(Fluid$
This is a specialized guide focused on using specifically for the Thermodynamics problem style found in Cengel’s textbooks (e.g., Thermodynamics: An Engineering Approach ), with emphasis on Iso (Isentropic, Isothermal, Isobaric, Isochoric) processes.
v2 = v1 "Final pressure given" P2 = 500 [kPa] T2 = temperature(Fluid$, P=P2, v=v2) u2 = intEnergy(Fluid$, P=P2, v=v2)
"Given final state: superheat to T2" T2 = 80 [C] v2 = volume(Fluid$, P=P2, T=T2) u2 = intEnergy(Fluid$, P=P2, T=T2) h2 = enthalpy(Fluid$, P=P2, T=T2)