US 12,305,538 B2
Guide vane ring and rotor blade ring for a turbofan engine
Christoph Mueller-Schindewolffs, Munich (DE); Markus Brettschneider, Munich (DE); Guenter Ramm, Munich (DE); and Franz Malzacher, Munich (DE)
Assigned to MTU AERO ENGINES AG, Munich (DE)
Filed by MTU Aero Engines AG, Munich (DE)
Filed on Apr. 14, 2023, as Appl. No. 18/300,400.
Claims priority of application No. 102022109455.3 (DE), filed on Apr. 19, 2022.
Prior Publication US 2023/0332505 A1, Oct. 19, 2023
Int. Cl. F01D 9/04 (2006.01); F02K 3/06 (2006.01)
CPC F01D 9/041 (2013.01) [F02K 3/06 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A guide vane ring for a low-pressure turbine of an aircraft gas turbine of a turbofan engine, the guide vane ring comprising:
a plurality of airfoils disposed consecutively in a direction of rotation, each airfoil being disposed with a stagger angle γv less than 45° (γv<45°) over the entire height of the respective airfoil, the stagger angle γv being taken on a pressure side of each airfoil between a chord and the direction of rotation,
wherein the plurality of airfoils comprises a first airfoil and a second airfoil adjacent to the first airfoil in the direction of rotation, the first and second airfoils being disposed relative to each other such that a ratio e/t, viewed in a conical section, results from:
a smallest distance e taken on the pressure side of the first airfoil from a trailing edge of the first airfoil to a suction side of the second airfoil, and
a pitch t of the airfoils,
such that e/t is less than 0.31 (e/t<0.31).
 
18. A method of operating a low-pressure turbine of an aircraft gas turbine of a turbofan engine, the method comprising
providing a rotor blade ring that comprises a plurality of airfoils disposed consecutively in a direction of rotation, wherein each airfoil is disposed with a stagger angle γb, which is γb<62°−(32°·hx), with respect to a respective radial position hx, dimensioned from zero at a radially inner end to one at a radially outer end of a respective airfoil, viewed in conical sections and taken at the different radial positions hx, through the leading and trailing edges, the stagger angle γb being taken on a pressure side of each airfoil between a chord and the direction of rotation,
wherein the plurality of airfoils comprises a first airfoil and a second airfoil disposed adjacent to the first airfoil in the direction of rotation, the first and second airfoils being disposed relative to each other such that a ratio e/t, viewed in a conical section, results from
a smallest distance e taken on the pressure side of the first airfoil from a trailing edge of the first airfoil to a suction side of the second airfoil, and
a pitch t of the airfoils,
such that e/t is less than 0.31 (e/t<0.31); and
rotating the rotor blade ring at an ADP speed of at least 8000 rpm and at most 1200 rpm.