Guide vane ring and rotor blade ring for a turbofan engine
A guide vane ring and/or a rotor blade ring for a low-pressure turbine of an aircraft gas turbine of a turbofan engine includes a plurality of airfoils disposed consecutively in a direction of rotation. The plurality of airfoils includes a first airfoil and a second airfoil adjacent to the first airfoil in the direction of rotation. The first and second airfoils are disposed relative to each other such that a ratio e/t, viewed in a conical section, results from a smallest free flow cross-section e taken on the pressure side of the first airfoil from its trailing edge 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).
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 γ v less than 45° (γ v <45°) over the entire height of the respective airfoil, the stagger angle γ v 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).
2. The guide vane ring according to claim 1 , wherein at least one airfoil has a metal angle β 1 , which for the at least one airfoil, at least in a radially outer 5% of a radial airfoil height h at a leading edge is greater than 50° (β 1 >50°).
3. The guide vane ring according to claim 1 , wherein at least one airfoil has a metal angle β 1 which for the at least one airfoil, at least in a radially outer 5% of a radial airfoil height h at a leading edge, is smaller than 85° (β 1 <85°).
4. The guide vane ring according to claim 1 , wherein the guide vane ring is adapted for use with a rotor capable of an ADP speed of at least 8000 and at most 12000 rpm.
5. The guide vane ring according to claim 1 , in which a mean radius r m is at least 0.15 m and at most 0.6 m.
6. The guide vane ring according to claim 1 , wherein a ratio h/b obtained with a radial airfoil height h of a respective airfoil to an axial grid width b is at least 2 and at most 5.5 (2≤h/b≤5.5).
7. The guide vane ring according to claim 1 , wherein at least one airfoil has at a trailing edge, of the at least one airfoil, at least at a respective duct height of at least 10% of the radial duct extent, a downstream angle β 2 which is at least 14° and at most 18° (14°≤β 2 ≤18°).
8. A low-pressure turbine of an aircraft gas turbine of a turbofan engine, the low-pressure turbine comprising the guide vane ring according to claim 1 .
9. The low-pressure turbine according to claim 8 , wherein the guide vane ring has a horizontal hub contour.
10. A turbofan engine, the turbofan engine comprising:
a fan;
the low-pressure turbine according to claim 8 ; and
a gearbox coupling the fan to the low-pressure turbine.
11. A rotor blade ring for a low-pressure turbine of an aircraft gas turbine of a turbofan engine, the rotor blade comprising:
a plurality of airfoils disposed consecutively in a direction of rotation,
wherein each airfoil is disposed with a stagger angle γ b , which is γ b <62°−(32°·h x ), with respect to a respective radial position h x , 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 h x , through the leading and trailing edges, the stagger angle γ b being taken on a pressure side of each airfoil between a chord and the direction of rotation,
and wherein the plurality of airfoils includes 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).
12. The rotor blade ring according to claim 11 , wherein at least one airfoil has a metal angle β 1 , which for the at least one airfoil, at least in a radially outer 5% of a radial airfoil height h at a leading edge is greater than 50° (β 1 >50°).
13. The rotor blade ring according to claim 11 , wherein at least one airfoil has a metal angle β 1 which for the at least one airfoil, at least in a radially outer 5% of a radial airfoil height h at a leading edge, is smaller than 85° (β 1 <85°).
14. The rotor blade ring according to claim 11 , wherein the rotor blade ring is capable of an ADP speed of at least 8000 and at most 12000 rpm.
15. The rotor blade ring according to claim 11 , in which a mean radius r m is at least 0.15 m and at most 0.6 m.
16. The rotor blade ring according to claim 11 , wherein a ratio h/b obtained with a radial airfoil height h of a respective airfoil to an axial grid width b is at least 2 and at most 5.5 (2≤h/b≤5.5).
17. The rotor blade ring according to claim 11 , wherein at least one airfoil has at a trailing edge, of the at least one airfoil, at least at a respective duct height of at least 10% of the radial duct extent, a downstream angle β 2 which is at least 14° and at most 18° (14°≤β 2 ≤18°).
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 γ b , which is γ b <62°−(32°·h x ), with respect to a respective radial position h x , 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 h x , through the leading and trailing edges, the stagger angle γ b 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.
19. 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 γ v less than 45° (γ v <45°) over the entire height of the respective airfoil, the stagger angle γ v 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),
wherein e/t is less than 0.31 over the entire height of each of the airfoils.