0
TECHNICAL PAPERS: Gas Turbines: Heat Transfer

Brush Seal Temperature Distribution Analysis

[+] Author and Article Information
Yahya Dogu1

Department of Mechanical Engineering,  Kirikkale University, Yahsihan, Kirikkale 71451, Turkeyydogu@kku.edu.tr

Mahmut F. Aksit

Faculty of Engineering and Natural Sciences,  Sabanci University, Tuzla, Istanbul 34956, Turkeyaksit@sabanciuniv.edu

1

To whom correspondence should be addressed.

J. Eng. Gas Turbines Power 128(3), 599-609 (Sep 06, 2005) (11 pages) doi:10.1115/1.2135817 History: Received August 30, 2005; Revised September 06, 2005

Brush seals are designed to survive transient rotor rubs. Inherent brush seal flexibility reduces frictional heat generation. However, high surface speeds combined with thin rotor sections may result in local hot spots. Considering large surface area and accelerated oxidation rates, frictional heat at bristle tips is another major concern especially in challenging high-temperature applications. This study investigates temperature distribution in a brush seal as a function of frictional heat generation at bristle tips. The two-dimensional axisymmetric computational fluid dynamics (CFD) analysis includes the permeable bristle pack as a porous medium allowing fluid flow throughout the bristle matrix. In addition to effective flow resistance coefficients, isotropic effective thermal conductivity as a function of temperature is defined for the bristle pack. Employing a fin approach for a single bristle, a theoretical analysis has been developed after outlining the brush seal heat transfer mechanism. Theoretical and CFD analysis results are compared. To ensure coverage for various seal designs and operating conditions, several frictional heat input cases corresponding to different seal stiffness values have been studied. Frictional heat generation is outlined to introduce a practical heat flux input into the analysis model. Effect of seal stiffness on nominal bristle tip temperature has been evaluated. Analyses show a steep temperature rise close to bristle tips that diminishes further away. Heat flux conducted through the bristles dissipates into the flow by a strong convection at the fence-height region.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic of brush seal heat transfer

Grahic Jump Location
Figure 2

Schematic of brush seal heat partition mechanism

Grahic Jump Location
Figure 3

Schematic of bristle heat transfer as an infinitely long fin

Grahic Jump Location
Figure 4

Bristle layout for calculation of convective heat transfer coefficient

Grahic Jump Location
Figure 5

Brush seal CFD model domain

Grahic Jump Location
Figure 6

Typical brush seal dimensions used in CFD model

Grahic Jump Location
Figure 8

Convective heat transfer coefficient versus mass flow rate∕pressure load

Grahic Jump Location
Figure 9

Pressure contours (in kilopascal) for ΔP=70kPa, qf=100kW∕m2

Grahic Jump Location
Figure 10

Velocity vectors (in meters per second) for ΔP=70kPa, qf=100kW∕m2

Grahic Jump Location
Figure 11

Temperature contours (in degrees Celsius)

Grahic Jump Location
Figure 12

Radial temperature distribution at the middle of the bristle pack for various pressure loads and frictional heat generations: (a) ΔP=70kPa, (b) ΔP=200kPa, (c) ΔP=350kPa, and (d) ΔP=700kPa

Grahic Jump Location
Figure 13

Maximum temperature for various pressure loads and frictional heat generations

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In