Design Procedure of a Rotating Cavity Rig for Hot Gas Ingestion Investigation

Orsini, Lorenzo; Picchi, Alessio; Bonini, Alessio; Innocenti, Luca; Benedetto, Daniele Di; Soghe, Riccardo Da; Mazzei, Lorenzo

doi:10.1115/gt2022-82676

Cited by 3 publications

(1 citation statement)

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“…The Mach number at the stator exit reaches a value above 0.3 and it was considered acceptable although lower than the typical values found in a high-pressure turbine. The design of the test rig is presented in greater detail in Orsini et al (2022).…”

Section: Test Rigmentioning

confidence: 99%

Commissioning of a Newly Designed Experimental Facility for Hot Gas Ingestion Investigation

Orsini,

Picchi,

Facchini

et al. 2023

European Conference on Turbomachinery Fluid Dynamics and Thermodynamics

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The aim of the present paper is to present first preliminary results obtained on an experimental facility which has been recently designed to study the flow ingestion from the main annulus into the first stage stator-rotor cavity of a high-pressure turbine. The test rig has been designed as a single stage facility suitable to be run at cold flow conditions and equipped with interchangeable stator and rotor cover plates aiming to mimic different real engine rim seals as close as possible. Besides the usual gas sampling measurements, the main innovation of the current test rig resides in the possibility to exploit optical accesses on the stator disk to obtain 2D effectiveness maps on both stator and rotor discs. Before starting the experimental campaign, proper commissioning tests have been performed. Afterwards, results obtained by using standard concentration techniques are reported along with preliminary ones obtained through the use of PSP to illustrate the feasibility of the optical measurements but also to demonstrate the importance of this approach in providing valuable data that can be used to validate future CFD models.

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Section: Test Rigmentioning

confidence: 99%

Commissioning of a Newly Designed Experimental Facility for Hot Gas Ingestion Investigation

Orsini,

Picchi,

Facchini

et al. 2023

European Conference on Turbomachinery Fluid Dynamics and Thermodynamics

View full text Add to dashboard Cite

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On the Use of Pressure-Sensitive Paint to Determine the Rim Sealing Effectiveness

Orsini,

Picchi,

Facchini

et al. 2023

Journal of Turbomachinery

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The control of cavities sealing has been a challenging problem since early gas turbine development stages and several aspects regarding the flow physics and the modelling of rim seal flows still represent an open question. Fundamental test cases have been used in the open literature to characterize the level of ingestion by varying the main flow parameters and the geometrical features. In most of them, the effectiveness is measured by using taps connected to a gas analyzer used to sample the concentration of a foreign gas on the stator surface used to seed the purge flow. Consequently, the results are usually single point measurements, unsteady effects are inevitably neglected, the intrusiveness of the approach must be carefully checked and the application on the rotor side demands for complex slip-rings or telemetry. To overcome these limitations, the current work presents the application of the PSP technique to the study of hot gas ingestion phenomena on a single stage rotating cold rig. The 2D distributions of partial pressure of oxygen collected through the wide optical accesses present in the rig were then related to the seal effectiveness. The proposed methodology was firstly validated through a comparison with the data obtained from standard gas sampling and then applied as main experimental technique. The analysis of the results highlighted the capabilities of the PSP to fast collect data on both stator and rotor side, including the tip of the seal tooth where non uniform efficiency distributions in the circumferential direction have been detected.

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Impact of the Purge Flow Density Ratio on the Rim Sealing Effectiveness in Hot Gas Ingestion Measurements

Orsini,

Picchi,

Facchini

et al. 2023

Journal of Turbomachinery

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Predicting the correct quantity of purge flow necessary to prevent excessive ingestion of hot gases while, at the same time, minimizing the penalties in terms of engine efficiency and aerodynamics represents a great challenge for the engine designers. Since CFD approaches are still expensive and time-consuming, especially if 3D domains and unsteady conditions have to be simulated, fundamental test cases, replicating actual engines geometries, are still a valid approach to calibrate correlations or simplified models such as the Orifice Model. However, most of the experimental studies deal with test rigs at room temperature and do not consider the effect of the density ratio between purge and main flows. To fill this gap, the present paper investigates the impact of the density ratio on the rim sealing effectiveness by performing a non-intrusive diagnostic based on the PSP technique. The analysis was performed on a cold test rig where two different values of density ratio were tested by using N2 (DR = 1) and CO2 (DR = 1.52) as purge flow. The PSP effectiveness maps allowed to calibrate the Orifice Model for the stator side and to fit the coefficients of the Buffer Ratio model for the rotor surface at different flow conditions in the Externally-Induced ingress regime. In conclusion, it is shown that the obtained results can be used to scale experimental data, generally collected at DR close to one, towards more representative engine values where the difference between the density of purge and main flows cannot be neglected.

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Design Procedure of a Rotating Cavity Rig for Hot Gas Ingestion Investigation

Cited by 3 publications

References 0 publications

Commissioning of a Newly Designed Experimental Facility for Hot Gas Ingestion Investigation

Commissioning of a Newly Designed Experimental Facility for Hot Gas Ingestion Investigation

On the Use of Pressure-Sensitive Paint to Determine the Rim Sealing Effectiveness

Impact of the Purge Flow Density Ratio on the Rim Sealing Effectiveness in Hot Gas Ingestion Measurements

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