Identification of Structural Stiffness and Damping Coefficients of a Shoed Brush Seal

Delgado, Adolfo; ́s, Luis San Andre

doi:10.1115/detc2005-84159

Cited by 6 publications

(11 citation statements)

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“…The structural stiffness and the equivalent damping of a 20-pad SBS were investigated by Delgado and San Andrés. 50 They discovered that the bristle-to-bristle and bristle-backplate contact found in both conventional brush seals and a SBS produces a stick-slip motion regime. SBS is similar to a HBS, but without the spring backing elements.…”

Section: Areas Of Practical Applications Of Brush and Labyrinth Sealsmentioning

confidence: 99%

“…The ability of the bristle pads to move in radial direction can relax manufacturing tolerances and makes the entire manufacturing process simpler compared to labyrinth seals. The cantilever pad elements also add considerable axial stiffness to the seal, 50 thus allowing for operation at higher differential pressures than with standard brush seals.…”

Section: Shoed and Hybrid Brush Seal Developmentsmentioning

confidence: 99%

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Brush seals and labyrinth seals in gas turbine applications

Aslan-zada

Mammadov

Dohnal

2012

Proceedings of the Institution of Mechanical Engineers, Part A:

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The overall efficiency of gas turbines is strongly affected by the performance of the sealing arrangement between the stationary and rotary components. Maintaining an accurate clearance during nominal and transient operation and providing effective damping is of key importance for seal designers. The implementation of brush seals as an alternative to labyrinth seals in a gas turbine engine is outlined in this article. A review of published literature is performed to analyze the leakage performance of brush seals and labyrinth seals. The emphasis lies on the importance of an accurate clearance control and the subsequent reduction in parasitic flows. Based on a discussion of the performance and integrity of brush seals in gas turbine applications their advantages over labyrinth seals are highlighted. Some attention is drawn into common drawbacks of brush seals and how these were improved over time to become more competitive and reliable. Finally, advanced concepts, technological aspects of the design of the brush seals influencing their leakage characteristics and future applications prospective are discussed. It was shown that one of the key advantages of brush seals over conventional labyrinth seals is their positive rotordynamic characteristic. The rotordynamic force coefficients demonstrate very low and generally negative cross-coupled stiffness thereby positively affecting the turbomachine operability in industrial gas turbine applications. The review concluded the need for further work on studying rotordynamic behaviour of brush seals operating at conditions more realistic to real engine operation environment in order to complete the understanding of the seal dynamics in real operation condition.

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Section: Areas Of Practical Applications Of Brush and Labyrinth Sealsmentioning

confidence: 99%

Section: Shoed and Hybrid Brush Seal Developmentsmentioning

confidence: 99%

Brush seals and labyrinth seals in gas turbine applications

Aslan-zada

Mammadov

Dohnal

2012

Proceedings of the Institution of Mechanical Engineers, Part A:

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“…Direct damping slightly increased with the rotor speed. Andrés et al [15,16] measured the stiffness and damping coefficients of a shoed brush seal, which connected pads to the bristle pack. Results for the hybrid brush seal (a second generation of shoed brush seal) showed that the stiffness of hybrid brush seal was not affected by the rotor speed, and the cross-coupled stiffness was much smaller than the direct stiffness.…”

Section: Introductionmentioning

confidence: 99%

Influence of Geometry on Rotordynamic Coefficients of Brush Seal

Yuan

Dowell

Chen

et al. 2017

International Journal of Turbo &Amp; Jet-Engines

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It has been observed that the geometry of a brush seal has a significant effect on the sealing performance. However, the relationship between rotordynamic coefficients and geometry factors of the brush seal itself are rarely considered. In this article, the rotordynamic coefficients of a typical single-stage brush seal for different geometries and operating conditions were numerically analyzed using CFD RANS solutions coupled with a non-Darcian porous medium model. The reaction force which plays an essential role in rotordynamic coefficients was obtained by integrating the dynamic pressure distribution. The influence of the bristle pack thickness, fence height, clearance size and other working condition parameters on aerodynamic force, stiffness coefficients, and damping coefficients of brush seal were presented and compared. In addition, the effects of various geometric configurations on pressure and flow features were also discussed.

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“…Experimental researches on the characteristics related to the brush seal have been presented in references. 11–13…”

Section: Introductionmentioning

confidence: 99%

Research on the leakage and dynamic characteristics of a new kind of radial annular seal and comparisons with labyrinth seals

Zhang

Yang

Tian

et al. 2013

Proceedings of the Institution of Mechanical Engineers, Part A:

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To minimize fluid leakage and improve rotordynamic stability of traditional seals, a new kind of radial annular seal is presented in this article. The structure and the sealing principle are analyzed. Compared to the traditional labyrinth seal, the fluid leakage direction is altered from the axial to radial direction. The flow resistance is increased, and the flowinduced force is reduced greatly. There is also a tremendous improvement in the wear resistance of the seal. Threedimensional numerical models of the traditional labyrinth seal and radial annular seal are set up. Calculated results show that the discharge coefficient of the radial annular seal is about 20% lower than that of the labyrinth seal. Though the rotating speed has a small influence on the radial seal force for both the radial annular seal and labyrinth seal, it has a large effect on the tangential seal force. The tangential seal force increases with the increasing speed, and the destabilizing force in the radial annular seal is reduced greatly when compared to that in the labyrinth seal. The radial seal force of the radial annular seal is about 1.5-2.5 times as strong as that of the labyrinth seal. The tangential seal force is about 30-50% lower than that of the labyrinth seal under the same eccentricity, and this ratio becomes larger and larger with the increasing speed. Finally, the dependency of the seal characteristics on the design parameters is studied. It is shown that the optimum ratios of the clearance s to the tooth thickness b (s/b) for the outward and inward flows are 4.5-5.5 and 11-13, respectively. The flow characteristics perform best with the ratio of the seal chamber width B to the tooth height H (B/H) on the same order of 5.5-7 for the two kinds of flows.

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Identification of Structural Stiffness and Damping Coefficients of a Shoed Brush Seal

Cited by 6 publications

References 0 publications

Brush seals and labyrinth seals in gas turbine applications

Brush seals and labyrinth seals in gas turbine applications

Influence of Geometry on Rotordynamic Coefficients of Brush Seal

Research on the leakage and dynamic characteristics of a new kind of radial annular seal and comparisons with labyrinth seals

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