터빈/Exhaust 상호간섭에서 비축대칭 입구 유동에 의한 영향에 대한 수치해석적 연구

In the commercial steam turbine, the exhaust hood guides the flow from the turbine to the condenser and transfers theleaving kinetic energy from the turbine to the potential energy. The steam turbine exhaust hood consists of a diffuser and a collector. The collector of the exhaust hood turns the flow direction from the turbine exit to the condenser about 90-deg, so its structure is asymmetric. Then distorted pressure profile is arisen by the nonaxisymmetric collector structure at the diffuser outlet. Thisasymmetric pressure-field propagates to the exit plane of theturbine through the diffuser. Thus the turbine may experience varying back pressure at different circumferential locations and distorted inflow condition for the exhaust hood is formed. For the complex geometry of the exhaust hood, unstructured mesh is used and the actuator disk model is adopted as a modeling of the whole turbine blade rows. Using the unstructured mesh and the actuator disk model, the interaction of the turbine and the exhaust hood is observed. To account for the effect of the distorted inflow condition, the result is compared with that of the exhaust hood calculation with the turbine exit condition as the inlet condition.