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SHAPED TRAILING EDGE FOR CENTRIFUGAL IMPELLER BLADE

IP.com Disclosure Number: IPCOM000248719D
Publication Date: 2016-Dec-29
Document File: 9 page(s) / 156K

Publishing Venue

The IP.com Prior Art Database

Abstract

A centrifugal impeller for a gas turbine engine includes a rotating disk with impeller blades. The trailing edges of the blades are shaped to reduce their thickness and thereby reduce the size of wakes propagating therefrom.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 30% of the total text.

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SHAPED TRAILING EDGE FOR CENTRIFUGAL IMPELLER BLADE

ABSTRACT

[0001] A centrifugal impeller for a gas turbine engine includes a rotating disk with

impeller blades. The trailing edges of the blades are shaped to reduce their thickness and

thereby reduce the size of wakes propagating therefrom.

BACKGROUND

[0002] This disclosure relates generally to gas turbine engines and more particularly to

gas turbine engine centrifugal compressors.

[0003] A centrifugal compressor is a known type of compressor used in a gas turbine

engine. It includes a rotating impeller, to impart kinetic energy to a gas flowing through

it, with a high swirl level (i.e. tangential velocity) at the impeller's exit. A stationary

diffuser surrounds the impeller and deswirler system follows the diffuser. Collectively,

the diffuser and the deswirler system function to convert the high kinetic energy received

from the impeller into the more useful form of static pressure, turn the air flow in a

meridional plane by 90 degrees or more, from an outward radial direction to a generally

axial direction, and reduce the high tangential velocity component to a small value.

[0004] The progression of impeller designs to higher tip speeds and more closely coupled

impellers and diffusers can challenge the high cycle fatigue capability of impellers by

driving up the unsteady pressure loading. To compensate for the additional forcing and

build robustness, the blade thickness is often increased. However, increasing blade

thickness can offset the gains in efficiency achievable through the higher tip speeds and

close coupling, specifically by increasing the strength of a wake propagating behind each

passing blade.

[0005] Described herein is a centrifugal impeller with blades configured to minimize the

losses associated with thicker impeller blades.

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BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The invention may be best understood by reference to the following description

taken in conjunction with the accompanying drawing figures in which:

[0007] FIG. 1 is a schematic exploded perspective view of a centrifugal compressor stage

of a gas turbine engine;

[0008] FIG. 2 is a top plan view of a trailing edge section of a first type of conventional

impeller blade;

[0009] FIG. 3 is a top plan view of a trailing edge section of a second type of

conventional impeller blade;

[0010] FIG. 4 is a top plan view of a trailing edge section of an exemplary impeller

blade;

[0011] FIG. 5 is a top plan view of a trailing edge section of an alternative impeller

blade;

[0012] FIG. 6 is a top plan view of a trailing edge section of another alternative impeller

blade; and

[0013] FIG. 7 is a top plan view of a trailing edge section of another alternative impeller

blade.

DETAILED DESCRIPTION OF THE CONCEPT

[0014] Referring to the drawings wherein identical reference numerals denote the same

elements throughout the various views, FIG. 1 depicts schematically a centrifugal

compressor 10 suitable for use in an aircraft ga...