Experimental and Computational Analysis of a Gas Compressor Windback Seal

Morrison, Gerald L.; Al-Ghasem, Adnan

doi:10.1115/gt2007-27986

Cited by 7 publications

(7 citation statements)

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“…The standard turbulence model is proved to be accurate for modeling of leakage flow through labyrinth seals with and without rotational effect included in the model [24][25][26]63].…”

Section: Problem Formulation 21 Geometry and Numerical Set-upmentioning

confidence: 99%

Labyrinth seals with application to turbomachinery

Ilieva

Pirovsky

2019

Materialwissenschaft Werkst

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It is well known that there exist losses of fluid through axial and radial gaps in turbomachines, leading to less efficiency. Every 1 % decrease in leakage flow through a high‐pressure gas turbine seals would result in a 0.4 % decrease in the specific fuel consumption [1]. Last decades, a number of solutions have been applied to overcome losses of fluid through axial and radial gaps. A feasible solution is the application of labyrinth seals to act as an obstacle on the way of flow leakages. This research is targeted to attain a seal configuration that has good dynamic sealing properties, higher compliance with the shaft, simple geometry for manufacturing and maintenance. The labyrinth seal must produce significant losses of kinetic energy in order to stop leaks passing through the sealed places. It is known that the turbine shaft exhibits modal and stress loads. Also, seals must be designed to resist loads and operate at maximum efficiency. The fulfilled numerical analysis shows that the proposed geometry causes intensive reduction of leakage flow rates and thus contributes to increase in the efficiency performance of stages under consideration.

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“…The standard turbulence model is proved to be accurate for modeling of leakage flow through labyrinth seals with and without rotational effect included in the model [24][25][26]63].…”

Section: Problem Formulation 21 Geometry and Numerical Set-upmentioning

confidence: 99%

Labyrinth seals with application to turbomachinery

Ilieva

Pirovsky

2019

Materialwissenschaft Werkst

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“…When the labyrinth seal is combined to a smooth rotor, a very good agreement between the analytic and the numerical computations at low pressure ratios was detected. For the windback seal, the analytic evaluation using the Morisson et al correlations seem to be valid for the cases described in [1] only. In Figure 13 the influence of the scallop number on the backflow rate was investigated.…”

Section: Impact Of the Rotational Speed And Directionmentioning

confidence: 98%

“…These values are much higher than the targets set in this manuscript (<5 kPa). Their C dw correlation is strictly valid for the geometry given in [1]: and the mass flow rate through the windback is calculated using:…”

Section: State Of the Artmentioning

confidence: 99%

“…For the windback seal, the analytic evaluation using the Morisson et al correlations seem to be valid for the cases described in [1] only. In Figure 13 the influence of the scallop number on the backflow rate was investigated.…”

Section: Impact Of Rotor Scallopsmentioning

confidence: 99%

“…Morisson and Al-Gahsem [1] have developed in their work on windback seals their C d correlation. They investigated windback seals at pressure differences of 34.5, 68.9 and 103.4 kPa.…”

Section: State Of the Artmentioning

confidence: 99%

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Numerical Investigation on Windback Seals Used in Aero Engines

et al. 2018

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Seals are considered one of the most important flow elements in turbomachinery applications. The most traditional and widely known seal is the labyrinth seal but in recent years other types like the brush or carbon seals were introduced since they considerably reduce the sealing air consumption. When seals are used for sealing of aero engine bearing chambers they are subjected to high "bombardment" through oil particles which are present in the bearing chamber. These particles mainly result from the bearings as a consequence of the high rotational speeds. Particularly when carbon or brush seals are used, problems with carbon formation (coking) may arise when oil gets trapped in the very tight gap of these seals. In order to prevent oil migration into the turbomachinery, particularly when the pressure difference over a seal is small or even negligible, significant improvement can be achieved through the introduction of so called windback seals. This seal has a row of static helical teeth (thread) and below this thread a scalloped or smooth shaft section is rotating. Depending on the application, a windback seal can be used alone or as a combination with another seal (carbon, brush or labyrinth seal). A CFD analysis carried out with ANSYS CFX version 11 is presented in this paper with the aim to investigate this seal type. The simulations were performed by assuming a two-phase flow of air and oil in the bearing compartment. Design parameters like seal clearance, thread size, scallop width, were investigated at different operating conditions.

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Investigations on the Discharge and Total Temperature Increase Characteristics of the Labyrinth Seals With Honeycomb and Smooth Lands

Yan

Song

et al. 2009

Journal of Turbomachinery

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The viscous work generated by the rotating components of a seal not only represents a direct loss of power but also causes an increase in the total temperature of fluid (windage effect). In order to study the discharge and total temperature increase characteristics of the stepped labyrinth seals with smooth and honeycomb lands, 3D Reynolds-averaged Navier–Stokes solutions from CFX is used in this work. At first, the influences of the inlet preswirl, leakage flow rate, and rotational speed on the total temperature increase in the convergent and divergent stepped labyrinth seals with smooth and honeycomb lands are conducted. The obtained 3D numerical results are well in agreement with the referenced experimental data. It shows that the utilized numerical approach has sufficient precision to predict the total temperature increase in seals. Then, a range of pressure ratios and four sizes of sealing clearance are performed to investigate the effects of sealing clearances and pressure ratio impact on the discharge and total temperature increase of the stepped labyrinth seals with honeycomb and smooth liners.

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Experimental and Computational Analysis of a Gas Compressor Windback Seal

Cited by 7 publications

References 0 publications

Labyrinth seals with application to turbomachinery

Labyrinth seals with application to turbomachinery

Numerical Investigation on Windback Seals Used in Aero Engines

Investigations on the Discharge and Total Temperature Increase Characteristics of the Labyrinth Seals With Honeycomb and Smooth Lands

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