A mathematical model that is used to predict the performance of steam engines. The Rankine cycle is an idealised thermodynamic cycle of a heat engine that converts heat into mechanical work. The heat is supplied externally to a closed loop, which usually uses water as the working fluid.
Steam leakage in a turbine of the Parsons type decreases as the pressure falls, and the turbine can continue to extract work from the steam at a very much lower pressure than is possible in a reciprocating engine. For this reason a steam turbine approximates more closely to the Rankine cycle than does a reciprocating engine, in as much as the expansion is more complete and continues right down to the condenser pressure.