A row-by-row off-design performance calculation method for turbines

The turbine component of a gas turbine engine is frequently subjected to extreme operation conditions associated with significant changes in mass flow, turbine inlet temperature, pressure and rotational speed. These off-design operation conditions significantly affect the flow deflection within the turbine stage, which consists of individual stator and rotor rows. As a result, the stage parameters representing the velocity diagram will change and affect the efficiency and performance of the stage and, thus, the turbine. A row-by-row calculation method is presented for predicting the performance behavior of turbines under extreme off-design conditions. The method is applied to a multistage turbine for which the off-design performance is calculated and compared with the measurement.