抄録
Recently, in response to the increasing environmental awareness and demands of operational flexibility, gas turbines for power generation must comply with exhaust gas regulations, not only at rated operation but also at partial-load conditions. To improve emission performance of constant speed single-shaft engines at partial-load conditions, compressors should be operated with low mass flow rate to optimize air-fuel ratio of combustors. Flow rate of constant speed compressors can be reduced by controlling angles of variable stator vane (VSV). Under these conditions, flow separation can be induced and it causes flow induced vibration and noise. They limit stable operation range of gas turbines. Thus, in this study, the way to predict the unstable behavior of compressors is investigated using unsteady flow simulation. The accuracy of the simulation is validated by utilizing a gas turbine test-rig. The way to enhance the stable operation range by optimizing the angles of VSV is also validated.
