PhD contract: Numerical and experimental modeling of overlapping piston ring seals in static, semi-static and dynamic operating conditions (M/F)

Job Description

Thesis Subject

At the CNRS, on the Futuroscope site, the PPrime Institute is recruiting a doctoral student to study the numerical modeling of overlapping piston ring seals in static, semi-static and dynamic operating conditions as part of the ANR/AEROSEAL-funded research project.

This thesis is being conducted within the framework of a partnership between the PPRIME Institute, Safran Aircraft Engines and CETIM, and the AEROSEAL chair, whose objective is to improve knowledge of aeronautical sealing.

Overlapping piston ring seals are used in numerous aeronautical applications, both civil and military. Their primary function is to ensure an airtight and/or oiltight seal between two pressurized engine cavities.

These rings can operate in different configurations:
- Static: the ring is fixed in its bore and provides a seal between two static parts (without relative movement between the two parts)
- Semi-static: the ring can move axially in its bore over a very short distance and provides a seal between two static parts
- Dynamic: the ring can move axially in its bore over a very short distance and provides a seal between two parts in relative movement (such as a "piston/bore" or "rotor/stator" system).

The estimation of leakage rates is currently carried out using an analytical approach that does not take into account the physicochemical properties of the ring, the interfacing parts, or their surface conditions.

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1-The objectives of the thesis are:
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- To understand fluid flows through inter-shaft seals
- To quantify leakages at the piston ring/bore and piston ring/rotor interfaces and at the clearance level
- To define sizing criteria
- To optimize the piston ring geometry (axial/radial dimensions; sealing clearance, surface finish, materials, etc.) for different application cases.

Refined numerical modeling of the seal ring validated by dedicated experimental results will enable the implementation of strategies to improve its operating conditions.

2-Task Description:
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- State of the art / monitoring of single- and two-phase fluid flow modeling
- Modeling of single- and two-phase flows through sealing rings in static configurations
- Modeling of single- and two-phase flows through sealing rings in semi-static configurations
- Modeling of single- and two-phase flows through sealing rings in dynamic configurations
- Exploitation of experimental test campaign results
- Master the dedicated test rig: understand operation, calibrate sensors, set up the protocol and data acquisition program, and conduct rig qualification tests,
- Perform experimental tests on the dedicated rig to validate the numerical model,
- Analyze results from experimental test campaigns: compare calculations with test data and validate the numerical model.

The candidate must hold a Master's degree in Mechanical or Aeronautical Engineering or in Materials Science with good training in mechanical design, numerical modeling of continuous media and a programming language.

Your Work Environment

The PhD student will be based at the Pprime Institute (pprime.fr) and will participate in project progress meetings at the sites of industrial partners Safran Aircraft Engines and CETIM Nantes.

Constraints and risks

- Doctoral School: enrolment at the University of Poitiers MIMME.
- Short trips within France and abroad are to be expected.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

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