Turbocharger turbine wheel
A turbocharger turbine assembly can include a turbine housing that includes a longitudinal axis, an exhaust inlet, a shroud portion, and an exhaust outlet; and a turbine wheel that includes a hub that includes a rotational axis aligned with the longitudinal axis of the turbine housing, a backdisk and a nose, where the rotational axis defines an axial coordinate (z) in a cylindrical coordinate system; and blades that extend outwardly from the hub, where each of the blades includes a shroud edge, a leading edge, a trailing edge, a pressure side, and a suction side, where the shroud edge includes a minimum axial coordinate position where the shroud edge meets the leading edge, and a maximum axial coordinate position where the shroud edge meets the trailing edge, and where, from the minimum axial coordinate position to the maximum axial coordinate position, the shroud edge has a decreasing radial coordinate position.
1. A turbocharger turbine assembly comprising:
a turbine housing that comprises a longitudinal axis, an exhaust inlet, an exhaust volute, an annular exhaust nozzle disposed a radial distance from the longitudinal axis, a shroud portion, a diffuser portion and an exhaust outlet; and
a turbine wheel that comprises a hub that comprises a rotational axis aligned with the longitudinal axis of the turbine housing, a backdisk and a nose, wherein the rotational axis defines an axial coordinate (z) in a cylindrical coordinate system that comprises a radial coordinate (r) and an azimuthal coordinate (Θ) in a direction of intended rotation about the rotational axis; and
blades that extend outwardly from the hub, wherein each of the blades comprises
a shroud edge,
a leading edge,
a trailing edge,
a pressure side, and
a suction side,
wherein the shroud edge comprises
a minimum axial coordinate position where the shroud edge meets the leading edge, and
a maximum axial coordinate position where the shroud edge meets the trailing edge, and
wherein, from the minimum axial coordinate position to the maximum axial coordinate position, the shroud edge comprises a decreasing radial coordinate position.
2. The turbocharger turbine assembly of claim 1 wherein the decreasing radial coordinate position of the shroud edge, where the shroud edge meets the trailing edge, is defined by a cone angle.
3. The turbocharger turbine assembly of claim 1 wherein, from the minimum axial coordinate position of the shroud edge to the maximum axial coordinate position of the shroud edge, the shroud portion of the turbine housing comprises a decreasing radial coordinate position.
4. The turbocharger turbine assembly of claim 3 wherein the decreasing radial coordinate position of the shroud portion of the turbine housing, at the maximum axial coordinate position of the shroud edge, is defined by a cone angle.
5. The turbocharger turbine assembly of claim 3 wherein the shroud portion of the turbine housing transitions to an intermediate portion that is intermediate the shroud portion and the diffuser portion that comprises a non-decreasing radial coordinate position.
6. The turbocharger turbine assembly of claim 5 wherein the non-decreasing radial coordinate position of the intermediate portion is a constant radial coordinate position.
7. The turbocharger turbine assembly of claim 5 wherein the intermediate portion transitions to the diffuser portion at a maximum axial coordinate position of the trailing edge and wherein the diffuser portion comprises an increasing radial coordinate position.
8. The turbocharger turbine assembly of claim 7 wherein the maximum axial coordinate position of the trailing edge is where the trailing edge meets the hub.
9. The turbocharger turbine assembly of claim 3 wherein the shroud portion of the turbine housing transitions to an intermediate portion that is intermediate the shroud portion and the diffuser portion wherein the transition is from a conical contour to a cylindrical contour at the maximum axial coordinate position of the shroud edge.
10. The turbocharger turbine assembly of claim 9 wherein the intermediate portion transitions to the diffuser portion, wherein the transition is from a cylindrical contour to a conical counter having an increasing radial coordinate position.
11. The turbocharger turbine wheel of claim 1 wherein a number of the blades is selected from a range of 3 blades to 30 blades.
12. The turbocharger turbine wheel of claim 1 wherein the decreasing radial coordinate position defines a cone angle that is one-half the opening angle of a cone and wherein the cone angle is selected from an angle in a range from 5 degrees to 20 degrees.
13. The turbocharger turbine wheel of claim 1 wherein the blades comprise radial inlet flow blades.
14. The turbocharger turbine wheel of claim 1 wherein the blades comprise mixed inlet flow blades.
15. A turbocharger comprising:
a compressor assembly;
a center housing assembly operatively coupled to the compressor assembly; and
a turbine assembly operatively coupled to the center housing assembly, wherein the turbine assembly comprises
a turbine housing that comprises a longitudinal axis, an exhaust inlet, an exhaust volute, an annular exhaust nozzle disposed a radial distance from the longitudinal axis, a shroud portion, a diffuser portion and an exhaust outlet; and
a turbine wheel that comprises a hub that comprises a rotational axis aligned with the longitudinal axis of the turbine housing, a backdisk and a nose, wherein the rotational axis defines an axial coordinate (z) in a cylindrical coordinate system that comprises a radial coordinate (r) and an azimuthal coordinate (Θ) in a direction of intended rotation about the rotational axis; and
blades that extend outwardly from the hub, wherein each of the blades comprises
a shroud edge,
a leading edge,
a trailing edge,
a pressure side, and
a suction side,
wherein the shroud edge comprises
a minimum axial coordinate position where the shroud edge meets the leading edge, and
a maximum axial coordinate position where the shroud edge meets the trailing edge, and
wherein, from the minimum axial coordinate position to the maximum axial coordinate position, the shroud edge comprises a decreasing radial coordinate position.