Patent ID: 7758297

Claim:
A method for flow optimization in multi-stage turbine-type machines comprising the steps of: optimizing an inflow of a third of three consecutive blade rings, a first and the third blade ring having a same number of blades and a same blade pitch angle and being coaxially situated on one of a rotor and a stator, a second blade ring coaxially situated on the other one of the rotor and the stator such that during operation of the multi-stage turbine type engine a relative rotation takes place between the second blade ring and the first and third blade rings, the second blade ring located between the first and third blade rings, the step of optimizing further comprising: ascertaining or predefining appropriate operating parameters to select an operating state of the turbine-type machine, determining a tolerance angle in the operating state, wherein the operating state has periodically occurring maxima of the obstruction (V max ) in an area of outlet edges of blade profiles of the second blade ring situated at a certain blade height, induced by wakes (N), the wakes originating from blade profiles of the first blade ring, the maxima of the obstruction moving from the area of outlet edges of the blade profiles of the second blade ring to an area of inlet edges of blade profiles of the third blade ring and deflecting onto the inlet edges of the blade profiles of the third blade ring within the tolerance angle, wherein the determining step further includes ascertaining a magnitude of the obstruction in the area of the outlet edge of a blade profile of the second blade ring based on a displacement thickness δ* for a pressure side and an intake side of the blade profile, calculated using the equation: δ * = ∫ 0 y e ⁢ ( 1 - ρ ⁢ ⁢ u ⁡ ( y ) ρ e ⁢ u e ⁡ ( y e ) ) ⁢ ⅆ y wherein ρ is a density of a flowing medium, u is a velocity of the flowing medium, y is a coordinate perpendicular to a reference line and e is an index for a boundary between the flow disturbed by a boundary layer and the flow undisturbed by the boundary layer.