Turbine Stator Well CFD Studies: Effect of Upstream Egress Ingestion

Georgakis, C.; Whitney, C.; Woollatt, G.; Stefanis, Vassilis; Childs, Peter

doi:10.1115/gt2007-27406

Cited by 4 publications

(2 citation statements)

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“…This effect was shown by Gentilhomme et al [9]. The effect of the re-ingestion of cooling air from upstream cavities was investigated by Georgakis et al [10]. It was shown that re-ingestion of upstream egress provided significant contribution to stator well cooling, which was quantified as improving themial effectiveness on the downstream cavity walls.…”

Section: Review Of Flowsmentioning

confidence: 93%

Experimental Investigation of Turbine Stator Well Rim Seal, Re-Ingestion and Interstage Seal Flows Using Gas Concentration Techniques and Displacement Measurements

Eastwood

Coren

Long

et al. 2012

Journal of Engineering for Gas Turbines and Power

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Gas turbine engine performance requires effective and reliable internal cooling over the duty cycle of the engine. Life predictions for rotating components subject to the main gas path temperatures are vital. This demands increased precision in the specification of the internal air system flows which provide turbine stator well cooling and sealing. This in turn requires detailed knowledge of the flow rates through rim seals and interstage labyrinth seals. Knowledge of seal movement and clearances at operating temperatures is of great importance when prescribing these flows. A test facility has been developed at the University of Sussex, incorporating a two stage turbine rated at 400 kW with an individual stage pressure ratio of 1.7:1. The mechanical design of the test facility allows internal cooling geometry to be rapidly reconfigured, while cooling flow rates of between 0.71 Cw, ENT (>nd 1.46 C^^ ENT, inay be set to allow ingress or egress dominated cavity flows. The main annulus and cavity conditions correspond to in cavity rotational Reynolds numbers of 1.71 x 10^< Reip<1.93 x 70*. Displacement sensors have been used to establish hot running seal clearances over a range of stator well flow conditions, allowing realistic flow rates to be calculated. Additionally, gas seeding techniques have been developed, where stator well and main annulus flow interactions are evaluated by measuring changes in gas concentration. Experiments have been performed which allow rim seal and re-ingestion flows to be quantified. It will be shown that this work develops the measurement of stator well cooling flows and provides data suitable for the validation of improved thermo-mechanical and CFD codes, beneficial to the engine design process.

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Section: Review Of Flowsmentioning

confidence: 93%

Experimental Investigation of Turbine Stator Well Rim Seal, Re-Ingestion and Interstage Seal Flows Using Gas Concentration Techniques and Displacement Measurements

Eastwood

Coren

Long

et al. 2012

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

show abstract

“…Georgakis et al [11] computationally investigated re-ingestion into a turbine statorwell, based on the experimental rig at Sussex. They showed that re-ingestion provided GTP-17-1331 Scobie 7 a significant contribution to stator well cooling, calculating an increase in thermal effectiveness of 1 to 1.5% on the cavity walls due to the presence of the upstream egress.…”

Section: Literature Reviewmentioning

confidence: 99%

Re-Ingestion of Upstream Egress in a 1.5-Stage Gas Turbine Rig

Scobie

Hualca

Patinios

et al. 2018

Journal of Engineering for Gas Turbines and Power

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In gas turbines, rim seals are fitted at the periphery of stator and rotor discs to minimize the purge flow required to seal the wheel-space between the discs. Ingestion (or ingress) of hot mainstream gases through rim seals is a threat to the operating life and integrity of highly stressed components, particularly in the first-stage turbine. Egress of sealing flow from the first-stage can be re-ingested in downstream stages. This paper presents experimental results using a 1.5-stage test facility designed to investigate ingress into the wheel-spaces upstream and downstream of a rotor disk. Re-ingestion was quantified using measurements of CO2 concentration, with seeding injected into the upstream and downstream sealing flows. Here, a theoretical mixing model has been developed from first principles and validated by the experimental measurements. For the first time, a method to quantify the mass fraction of the fluid carried over from upstream egress into downstream ingress has been presented and measured; it was shown that this fraction increased as the downstream sealing flow rate increased. The upstream purge was shown to not significantly disturb the fluid dynamics but only partially mixes with the annulus flow near the downstream seal, with the ingested fluid emanating from the boundary layer on the blade platform. From the analogy between heat and mass transfer, the measured mass-concentration flux is equivalent to an enthalpy flux, and this re-ingestion could significantly reduce the adverse effect of ingress in the downstream wheel-space. Radial traverses using a concentration probe in and around the rim seal clearances provide insight into the complex interaction between the egress, ingress and mainstream flows.

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Turbine Stator Well CFD Studies: Effects of Coolant Supply Geometry on Cavity Sealing Performance

Andreini

Soghe

Facchini

2010

Journal of Turbomachinery

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The increase of aeroengine performance through the improvement of aerodynamic efficiency of core flow is becoming more and more difficult to achieve. However, there are still some devices that could be improved to enhance global engine efficiency. Particularly, investigations on the internal air cooling systems may lead to a reduction of cooling air with a direct benefit to the overall performance. At the same time, further investigations on heat transfer mechanisms within turbine cavities may help to optimize cooling air flows, saving engine life duration. This paper presents a computational fluid dynamics (CFD) study aimed at the characterization of the effects of different geometries for cooling air supply within turbine cavities on wall thermal effectiveness and sealing mass flow rate. Several sealing air supply geometries were considered in order to point out the role of cooling air injection position, swirl number, and jet penetration on the cavities’ sealing performance. Steady state calculations were performed using two different computational domains: the first consists of a sector model of the whole turbine including the second stator well, while the second is a cut-down model of the stator well. Thanks to the simplified geometry of the test rig with respect to actual engines, the study has pointed out clear design suggestions regarding the effects of geometry modification of cooling air supply systems.

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Turbine Stator Well CFD Studies: Effect of Upstream Egress Ingestion

Cited by 4 publications

References 0 publications

Experimental Investigation of Turbine Stator Well Rim Seal, Re-Ingestion and Interstage Seal Flows Using Gas Concentration Techniques and Displacement Measurements

Experimental Investigation of Turbine Stator Well Rim Seal, Re-Ingestion and Interstage Seal Flows Using Gas Concentration Techniques and Displacement Measurements

Re-Ingestion of Upstream Egress in a 1.5-Stage Gas Turbine Rig

Turbine Stator Well CFD Studies: Effects of Coolant Supply Geometry on Cavity Sealing Performance

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