Thibaud Plantegenet Curriculum Vitae

Thibaud Plantegenet Curriculum vitae

11 rue Arsène Orillard, Poitiers, France | [email protected] | +335 4949 6522 French citizen | linkedin.com/in/thibaud-plantegenet | researchgate.net/proﬁle/Thibaud_Plantegenet

SUPPORTING STATEMENT

My research interest is mainly focus on the rotordynamics and the related fields to develop numerical and experimental aspects. During my PhD, I worked on fluid film bearings and particularly on the Morton effect (synchronous instability thermally induced). During my year as a research assistant, I focused my research on thermal management of tilting pad bearing and on the use of ultrasonic sensors to follow air bubbles/pockets inside the film on a hydrodynamic bearing. My previous research is quasi exclusively experimental, so I am very comfortable with instrumentation, data acquisition, experiment protocol and post-processing. Unfortunately, my last experience in numerical aspects of rotordynamics come from my master’s degree internship, therefore I would love to do numerical rotordynamic again.

RESEARCH EXPERIENCE

Sep 2019 - Teaching and research assistant, University of Poitiers - Pprime Institute, France. Aug 2020 My current research is about two subjects concerning the improvement of journal bearing and its understanding : Analysis of the cavitation on statically and dynamically loaded cylindrical journal bearing by the use of ultrasonic measurement; Design of innovative tilting pad journal bearing in order to improve its thermal behaviour under static load, i.e. reducing the thermal distortion of loaded pads.

Oct 2016 - PhD. student, University of Poitiers - Pprime Institute, France. Aug 2019 Supervisors: Pr. Mihai Arghir, Pr. Olivier Bonneau, Dr. Pascal Jolly. Subject: Experimental Analysis of the Morton Effect Development of a journal bearing test rig; Design of plain and tilting pad journal bearings; Experimental analysis of the Morton effect induced on a journal bearing (plain and tilting pad) in rigid and flexible rotors; Experimental identification of dynamic coefficients of bearings using an electro-magnetic actuator.

Feb 2016 - Internship in rotordynamics, EDF R&D, France Aug 2016 Supervisor: Dr. Mohamed-Amine Hassini. Subject: Numerical Modelling of Turbo-Generator Shaft Bend.

TEACHING EXPERIENCE

Sep 2019 - Teaching and research assistant, University of Poitiers - Pprime Institute, France. Aug 2020 Lecture, tutorial and project courses mainly in Statics and Kinematics mechanics, Mechanical design, CAD and Functional speciﬁcation for approximatively 260h.

Sep 2017 - Teaching Assistant, University of Poitiers - Angoulême Institute of Technology Aug 2019 Tutorial courses in Strength of Materials (10h) and project courses in Classical and Solid mechanics (108h) and Mathematics (10h).

1 EDUCATION

Sep 2016 - PhD. degree, University of Poitiers, France. Dec 2019 PhD. thesis : Experimental Analysis of the Morton Eﬀect (thesis in French). More than 100h of doctoral training especially in education.

2014 - 2016 Master’s degree in engineering, University of Poitiers, France. Valedictorian, French equivalent to GPA 4. Scholarship from foundation "Poitiers Université". Merit scholarship from "CROUS". Major courses: Tribology, Photomechanics, Robotics.

2013 - 2014 Bachelor’s degree in engineering, University of Poitiers, France. French equivalent to GPA 4. Major courses: Classical mechanics, Continuum mechanics, FEM, Numerical analysis.

2012 - 2013 Bachelor’s degree in engineering, Dijon Institute of Technology, France French equivalent to GPA 4. Major courses : Mechanical design, Solid mechanics.

PUBLICATIONS & COMMUNICATIONS

Publication in international journal [IPTP1] T. Plantegenet, M. Arghir, M.A. Hassini & P. Jolly (2020) The Thermal Unbalance Ef- fect Induced by a Journal Bearing in Rigid and Flexible Rotors : Experimental Analysis, Tribology Transactions 63(1), pp.52–67, DOI:10.1080/10402004.2019.1658836. [IPTP2] T. Plantegenet, M. Arghir & P. Jolly (2020) Experimental Analysis of the Thermal Unbal- ance Eﬀect of a Flexible Rotor Supported by a Flexure Pivot Tilting Pad Bearing, Mechanical Systems and Signal Processing, 145 106953, DOI : https://doi.org/10.1016/j.ymssp.2020.106953

Communications in international conference [ICTP1] T. Plantegenet, M. Arghir, S. Zhang, M.A. Hassini, P. Jolly : Experimental Analysis of Large Amplitude Synchronous Vibrations Induced by Journal Asymmetric Heating, ASME Turbo Expo 2018 : Turbomachinery technical conference and exposition. June 11-15 2018, Oslo, Norway. ASME paper number GT2018-77322 (Poster). [ICTP2] T. Plantegenet, M. Arghir, P. Jolly, M.A. Hassini : Synthesis of the Experimental Analy- ses of Thermal Unbalance Effects Induced by Cylindrical and Tilting Pad Journal Bearings, 75th STLE Annual Meeting & Exhibition, May 3-7 2020, Chicago, Illinois, USA (Cancelled due to Covid-19). [ICTP3] T. Plantegenet, M. Arghir, J. Mahfoud: Experimental Identification of Dynamic Coeffi- cients of Fluid Film Bearings by Using Electro-Magnetic Actuator, 17th International Symposium on Magnetic Bearings (ISMB17), December 1–4 2020, Rio de Janeiro, Brazil (Extend abstract submitted).

Communication in national conference [NCTP3] T. Plantegenet, M. Arghir, P. Jolly : Experimental Analysis of Transient Thermal Eﬀects in a Flexible Rotor Supported by Tilting Pad Journal Bearing, 18th workshop EDF-Pprime : Chal- lenges in sliding bearing technologies for clean and low carbon energy applications, October 10-11 2019, EDF Lab Paris-Saclay, France (Poster).

2 RESEARCH EXPERIENCE DESCRIPTION

During my previous experiences at the University of Poitiers (PhD + teaching and research assistant), I developed a test rig especially designed to study the Morton effect on a fluid film bearing. The test rig was designed with a simple architecture of a rotor supported by one ball bearing on a side (DE side) and one fluid film bearing (cylindrical, tilting pad) on the other side (NDE side). This architecture offer a very flexible test rig in order to test rigid or flexible rotor with various types of bearings and the possibility to add static or dynamic loads and more instrumentation.

Experimental analysis of the Morton Effect The Morton effect is a thermally induced increase of synchronous vibrations amplitudes of rotors. The high shearing of fluid film in a journal bearing (generally induced by an unbalance) can produce an asymmetric heating of the rotor which causes its thermal bending and increasing the unbalance. The symptoms of this phenomenon in real machinery are : (1) the evolutions of synchronous vibrations (amplitude and phase) against time during constant operation, that are called spiral vibrations and (2) the hysteresis behaviour during start-up and cost-down due to the thermal bending of the rotor. Spiral vibrations can appears in three states : converging spirals (stable Morton effect), diverging spirals (unstable Morton effect), oscillating spirals (limit Morton effect). The goal of this study was to experimentally enlightened these three appearances of spiral vibrations on the dedicated test rig. In order to measure the displacements of the rotor and so the spiral vibrations, two planes of two inductive proximity probes were mounted at each side of the fluid film bearing. Temperatures of the bearing were measured with ten to twenty thermocouples depending of the type of the bearing. The temperatures on shaft surface were measured with five thermocouples insert inside the shaft and with a slip-ring. Three different configurations of the rig were tested with one rigid rotor or one flexible rotor (i.e. operating conditions close to the 1st bending mode) and with two bearings : 1. Short rotor (rigid) supported by a cylindrical journal bearing : This configuration allowed to show the stable Morton effect with the observation of converging spiral vibrations, the hysteresis behaviour and a temperature difference on the shaft surface but also the confirmation of literature results. 2. Long rotor (flexible) supported by a cylindrical journal bearing : At a speed near the first bending mode of the rotor, the unstable Morton effect appears and results show that the stability of the Morton effect is related with start-up time and bearing seizure phenomenon. 3. Long rotor (flexible) supported by a flexure pivot tilting pad bearing : This configuration showed that the start-up time haven’t influence on the stability of the Morton effect and so that this type of bearing accept more differential heating and thermal expansions (it is less sensitive to bearing seizure). Moreover this configuration showed that the variation of unbalance had an influence on the stability of the Morton effect and the position of the heating one the shaft. The results of the two first configurations were published in the Tribology Transactions journal [IPTP1] and in Mechanical Systems and Signal Processing journal [IPTP2] for the results obtained with the third configuration.

Experimental identification of dynamic coefficients of fluid film bearings This study was focused on the design of an Electo-Magnetic Actuator (EMA) in order to perform the experimental identification of cylindrical and tilting pad bearings dynamic coefficients. The originality of this work is the modification of the force-current formulation for taking into account an initial eccentricity of the rotor mounted with the EMA and the in-situ calibration of the EMA. The study was conducted in collaboration with Jarir Mahfoud, Associate professor at INSA Lyon and should conclude with a communication at the International Symposium on Magnetic Bearings [ICTP3] and by a publication.

3 Experimental analysis of cavitation in fluid film bearings In fluid film bearings we talk about cavitation in reference of air bubbles or air pockets present in the liquid film. Three cases can be identified : (1) When a bearing is statically loaded an area of air is present due to a depression in the fluid film, this area of air is fixed for a constant operating condition. (2) When a bearing is dynamically loaded, the assumption is that this area of air is turning synchronously with the rotor. (3) When the real cavitation is present i.e. small bubbles or pockets of air are created inside the film. The main goal of this experimental analysis of cavitation on a fluid film bearing is to follow the area of air on the bearing when it is dynamically loaded (2). The particularity of this work is the use of ultrasonic sensors (more than 40) installed on the bearing to follow bubbles/pockets of air on the fluid film. This work is in partnership with the University of Sheffield and the company Leonardo testing services. The bearing was developed to be tested on our test rig and the ultrasonic sensors were installed by our partners. Reference measurements have been realized and in-situ measurements have just started to observed the case (1) well known numerically.

Thermal management of tilting pad bearing The goal of the thermal management of the tilting pad bearing is to reduce the temperature diﬀer- ence on pads and then reduce thermal distortion and so ensure optimal operating conditions of the machinery. After the proof of concept of our innovative system on a simple model, a new bearing integrating this system is under ﬁnal design. It will be built in few months to be test thereafter.

Reviews

Reviewer for several journals and one conference : Journal of Vibration and Control, ASME Turbo Expo 2019 and Journal of Engineering Tribology, mainly about hydrodynamic bearings, foil bearings, active magnetic bearings and the Morton eﬀect.