Entropy Balance

• ΔS_system = S_transfer + S_GEN
• ΔS_system = S_final − S_initial
• ΔS_system = m(s_final − s_initial) using specific entropys_transfer comes from heat transfer, Q, or from mass flow  ,If heat transfer occurs, s_transfer = Q/TIf mass flow occurs,
• S_transfer = m × s (for mass entering the system)
• S_transfer = −m × s (for mass leaving the system)
• S_GEN = 0 for an internally reversible process
• S_GEN > 0 for a real, irreversible process

For a closed system (no mass flow):

In terms of rate:

For an adiabatic system (when dQ = 0):

For an open system steady flow process: