Aerodynamic Performance Research of Chordwise Swept Blade Cascade HP Stage at Off-design Condition

摘要

In order to research the chordwise swept cascade stage control mechanism for internal flow field under the off-design condition, the 600 MW supercritical steam turbine HP rotor and static blades were selected as prototypes. The chordwise fore-swept cascade stage and chordwise aft-swept cascade stage were achieved with 30% blade height and 20°, -20° swept angle respectively. The three cascades passage flow numerical simulation was conducted by CFD software. The computed results indicated that the degree of reaction and isentropic efficiency of the three cascade stages were changed very little in the scope of 70～120% design flux and decreased sharply when the inlet flux was less than 50% design flux. On the whole, chordwise fore-swept cascade stage had the best aerodynamic performance.