Work of a polytropic process w- Vn (constant）Vg-"-(constant0）V-n (n≠1) 1-n (p2V)vI-"-(piV)VI-" (Any fluids) 1-n mR(T2-T) (ideal gas,.n≠1) 1-n or w= R(T-T) for unit mass,ideal gas 1-n isothermal [v:dv W constant (n=1) (Any fluids) (ideal gas,n 1) or w=RTIn业 mRT In V for unit mass,ideal gas y 上降文通大学 March 23,2018 5 SHANGHAI JIAO TONG UNIVERSITYMarch 23, 2018 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