Work of a polytropic process m- w= Vn (constant）V3-"-(constant)）V}-" (n卡1) 1-n (pV)Vg-"-(p,V）V-nt (Any fluids) 1-n 11-n mR(T2-Ti) (ideal gas,n≠I) 1-n or w= (T-T) for unit mass,ideal gas 1-n isothermal [v dv W constant v= V (n=1) (Any fluids) (ideal gas,n 1) or mRT In- w=RTIn for unit mass,ideal gas 上泽通大学 Mar/15,Wed,2017 5 SHANGHAI JIAO TONG UNIVERSITYMar/15, Wed, 2017 5 Work of a polytropic process isothermal (Any fluids) (Any fluids)   2 1 1 R T T w n    or for unit mass, ideal gas for unit mass, ideal gas 2 1 RT ln v w v  or