Group of blade rows

Patent metadata

Field	Value
Publication number	US-9822645-B2
Application number	US-201514626565-A
Country	US
Kind code	B2
Filing date	Feb 19, 2015
Priority date	Feb 27, 2014
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

The present invention relates to a blade row group arrangeable in a main flow path of a fluid-flow machine and including N adjacent member blade rows firmly arranged relative to one another in both the meridional direction and the circumferential direction, with the number N of the member blade rows being greater than/equal to 2 and (i) designating the running index with values between 1 and N, with a front member blade row (i) as well as a rear member blade row (i+1) being provided, and with the blade row group having two main flow path boundaries. It is provided that there is a gap between one blade end of at least one blade of at least one of the member blade rows and at least one of the two main flow path boundaries.

First claim

What is claimed is:

1. A blade row group for a main flow path of a fluid-flow machine comprising:
N adjacent member blade rows firmly arranged relative to one another in both a meridional direction and a circumferential direction, with a quantity N of the N adjacent member blade rows being greater than or equal to 2 and (i) designating a running index with values between 1 and N, with a front member blade row (i) as well as a rear member blade row (i+1) being provided, the blade row group having two main flow path boundaries,
a gap provided between a blade end of at least one blade of at least one of the member blade rows and at least one of the two main flow path boundaries, where the at least one blade and the at least one of the two main flow path boundaries are immovable relative to one another in the circumferential direction, and where the gap extends along at least part of a profile depth of the at least one blade along the at least one of the two main flow path boundaries;
wherein the gap comprises a partial rear gap at at least one of the two main flow path boundaries of blades of the rear member blade row (i+1), the partial gap starting aft of leading edges of the blades of the rear member blade row and extending to the trailing edges of the blades of the rear member blade row (i+1).

2. The blade row group in accordance with claim 1 , wherein the gap includes a front gap positioned at blade ends of blades of the front member blade row (i) and extending over an entire profile depth of the blades of the front member blade row (i).

3. The blade row group in accordance with claim 1 , wherein the gap includes a partial front gap positioned at blade ends of blades of the front member blade row (i) and extending over a partial section of a profile depth of the blades of the front member blade row (i).

4. The blade row group in accordance with claim 3 , wherein the partial front gap is provided inside a center profile area and does not touch any of leading edges and trailing edges of the blades of the front member blade row (i).

5. The blade row group in accordance with claim 3 , wherein the partial front gap is provided inside a partial area of the profile depth extending up to trailing edges of the blades of the front member blade row (i).

6. The blade row group in accordance with claim 1 , wherein the gap includes a front partial gap on both blade ends of blades of the front member blade row (i), the front partial gap extending over a partial section of a profile depth of the blades of the front member blade row (i).

7. The blade row group in accordance with claim 1 , wherein the gap includes on the front member blade row (i), a front gap or partial front gap at the at least one of the two main flow path boundaries and, when viewing the blade row group at the at least one of the two main flow path boundaries in a meridional flow line section (u-m plane) extending at an infinitesimally small distance from the at least one of the two main flow path boundaries, the leading edges of the blades of the rear member blade row (i+1) are arranged in a vicinity of pressure sides and trailing edges of blades of the front member blade row (i).

8. The blade row group in accordance with claim 7 , and further comprising a secondary passage formed between pressures sides of blades of the front member blade row (i) and suction sides of the blades of the rear member blade row (i+1), where a length v of the secondary passage is defined as a distance between trailing edge points of blades of the front member blade row (i) and leading edges points of the blades of the rear member blade row (i+1) in a direction of a tangent on a skeleton line at the trailing edge points, and is measured positively upstream, where the secondary passage length v, relative to a chord length l(i) of the front member blade row (i) has values greater than zero, in accordance with v/l(i)>0.

9. The blade row group in accordance with claim 1 , wherein when viewing the blade row group in a meridional flow line section (u-m plane) extending at an infinitesimally small distance from the at least one of the two main flow path boundaries, in an area without a gap in a profile section face and in an area with a gap in a profile end face, a profile section face is separated from a profile end face by a front limit line lgv, a skeleton line SKL is defined in each blade profile in a middle between a suction side and a pressure side, a profile chord Se is defined as a respective pressure-side tangent on each blade profile, a profile depth l is measured in a direction of the profile chord Se from a respective leading edge to a respective trailing edge, a respective partial gap depth cv is measured in a direction of the profile chord Se from the respective trailing edge to an intersection point of the respective skeleton line SKL with the front limit line lgv, and the partial gap depth cv is defined in accordance with 0.05<cv/l<0.75.

10. The blade row group in accordance with claim 1 , wherein the gap includes a partial front gap on blades of the front member blade row (i), and a depth cv(i) of the partial front gap is set at a selected ratio to a secondary passage length v and to a profile depth l(i) of the front member blade row (i), in accordance with a rule:
( v+ 0.3* l ( i ))/ l ( i )−0.3< cv ( i )/ l ( i )<( v+ 0.3* l ( i ))/ l ( i )+0.3.

11. The blade row group in accordance with claim 1 , wherein the gap includes a partial front gap on blades of the front member blade row (i) and, in an area between a front limit line lgv and trailing edges of the blades of the front member blade row (i), at least one gap break, the gap break having a local connection to the at least one of the two main flow path boundaries dividing the partial front gap.

12. The blade row group in accordance with claim 1 , wherein a limit line for the partial rear gap, on at least part of a course of the limit line between a point on a profile pressure side and a point S relative to a profile end face is convex, to obtain a transition which is favorable for flow between the profile pressure side and the limit line.

13. The blade row group in accordance with claim 1 , and further comprising, in an area of the partial rear gap, a flat or curved section through a blade profile of the rear member blade row (i+1), where the flat or curved section is oriented perpendicular to a u-m plane extending at an infinitesimally small distance from the at least one of the two main flow path boundaries and passing through the partial rear gap, where, in the flat or curved section due to the partial rear gap, a flow duct results between a profile end face and the at least one of the two main flow path boundaries, where the profile end face is convex at least in a transitional area towards a profile pressure side.

14. The blade row group in accordance with claim 1 , and further comprising, in an area of the partial rear gap, a flat or curved section B-B through a blade profile of the rear member blade row (i+1), where the flat or curved section is oriented perpendicular to a u-m plane extending at an infinitesimally small distance from the at least one of the two main flow path boundaries and passing through the partial rear gap, where, in the flat or curved section due to the partial rear gap, a flow duct results between a profile end face and the at least one of the two main flow path boundaries, where a flow duct width kw is measured between the profile end face and the at least one of the two main flow path boundaries perpendicular to the at least one of the two main flow path boundaries, where the flow duct width kw decreases in a direction of a p

Assignees

• Rolls Royce Deutschland Ltd & Co Kg

Inventors

• Guemmer Volker

Classifications

• Y02T50/673

  Cross-Sectional Technologies · mapped topic

• F01D9/041

  using blades (F01D5/148 takes precedence) · CPC title

• F05D2240/125

  related to the tip of a stator vane · CPC title

• F05D2240/24

  for turbines · CPC title

• F01D5/145 Primary

  Means for influencing boundary layers or secondary circulations (for compressors F04D29/68) · CPC title