COMPARATIVE EXPERIMENTAL INVESTIGATION ON AERODYNAMIC PERFORMANCE OF A STEAM TURBINE CASCADES, PART Ⅱ - STATOR VANES

摘要

In this paper, the eighth and the ninth stage stator blades of a marine steam turbine are improved and the experimental research has been carried out on aerodynamic performance at 50% blade height of the original and the improved plane cascades. The experimental results indicate that both of the two original siator (ades) are uniform loading type, which are improved and designed as the aft-loaded. The results also show that, comparing with the original blade, the improved one can shorten the length of reverse pressure gradient, therefore the reverse pressure gradient is reduced and the adaptability of cascades to incidence variation is enhanced. Meanwhile, the thin trailing edge of aft-loaded blade not only increases the base pressure of the wake region, but also reduces the width of the wake region. In addition, the results reveal that the losses of modified blades are lower than the original ones under the experimental conditions of different exit Mach numbers and different angle of incidences.