Access profile

Given the multidisciplinary nature of the scientific field of the doctoral programme in Mechanical, Fluids and Aerospace Engineering, there are a wide range of degrees that qualify applicants for admission. The most suitable prior learning for admission corresponds to degrees in engineering and sciences. In the near future, scientific and technological academic backgrounds will be considered suitable. In all cases, students must have completed a master’s degree or 60 ECTS of a master’s degree in subjects relating to the scientific field of the programme.

Output profile

Doctoral candidates who complete a doctoral degree will have acquired the following competencies, which are needed to carry out quality research (Royal Decree 99/2011, of 28 January, which regulates official doctoral studies):

a) A systematic understanding of the field of study and a mastery of the research skills and methods related to the field.
b) An ability to conceive, design or create, put into practice and adopt a substantial process of research or creation.
c) An ability to contribute to pushing back the frontiers of knowledge through original research.
d) A capacity for critical analysis and an ability to assess and summarise new and complex ideas.
e) An ability to communicate with the academic and scientific community and with society in general as regards their fields of knowledge in the manner and languages that are typical of the international scientific community to which they belong.
f) An ability to foster scientific, technological, social, artistic and cultural progress in academic and professional contexts within a knowledge-based society.

The award of a doctoral degree must equip the graduate for work in a variety of settings, especially those requiring creativity and innovation. Doctoral graduates must have at least acquired the personal skills needed to:

a) Develop in contexts in which there is little specific information.
b) Find the key questions that must be answered to solve a complex problem.
c) Design, create, develop and undertake original, innovative projects in their field.
d) Work as part of a team and independently in an international or multidisciplinary context.
e) Integrate knowledge, deal with complexity and make judgements with limited information.
f) Offer criticism on and intellectually defend solutions.

Finally, with respect to competencies, doctoral students must:
a) have acquired advanced knowledge at the frontier of their discipline and demonstrated, in the context of internationally recognised scientific research, a deep, detailed and well-grounded understanding of theoretical and practical issues and scientific methodology in one or more research fields;
b) have made an original and significant contribution to scientific research in their field of expertise that has been recognised as such by the international scientific community;
c) have demonstrated that they are capable of designing a research project that serves as a framework for carrying out a critical analysis and assessment of imprecise situations, in which they are able to apply their contributions, expertise and working method to synthesise new and complex ideas that yield a deeper knowledge of the research context in which they work;
d) have developed sufficient autonomy to set up, manage and lead innovative research teams and projects and scientific collaborations (both national and international) within their subject area, in multidisciplinary contexts and, where appropriate, with a substantial element of knowledge transfer;
e) have demonstrated that they are able to carry out their research activity in a socially responsible manner and with scientific integrity;
f) have demonstrated, within their specific scientific context, that they are able to make cultural, social or technological advances and promote innovation in all areas within a knowledge-based society;
g) have demonstrated that they are able to participate in scientific discussions at the international level in their field of expertise and disseminate the results of their research activity to audiences of all kinds.

Number of places

20

Duration of studies and dedication regime

Duration
The maximum period of study for full-time doctoral studies is three years, counted from the date of admission to the programme to the date of submission of the doctoral thesis. The academic committee of the doctoral programme may authorise a doctoral candidate to pursue doctoral studies on a part-time basis. In this case, the maximum period of study is five years, counting from the date of admission to the programme to the date of submission of the doctoral thesis. For calculating these periods, the date of admission is considered to be the date of the first enrolment for tutorials, and the date of submission the moment in which the Doctoral School officially deposits the doctoral thesis.

For full-time doctoral candidates, the minimum period of study is two years, counted from the date of an applicant's admission to the programme until the date on which the doctoral thesis is deposited; for part-time doctoral candidates it is four years. When there are justified grounds for doing so, and the thesis supervisor and academic tutor have given their authorisation, doctoral candidates may request that the academic committee of their doctoral programme exempt them from the minimum period of study requirement.

The calculation of periods of study will not include periods of absence due to illness, pregnancy or any other reason provided for in the regulations in force. Students who find themselves in any of these circumstances must notify the academic committee of the doctoral programme, which, where appropriate, must inform the Doctoral School. Doctoral candidates may also temporarily withdraw from the programme for up to one year, and this period may be extended for an additional year. Doctoral candidates who wish to interrupt their studies must submit a justified request to the academic committee of the doctoral programme, which will decide whether or not to approve the request. Each programme will establish conditions for readmission to doctoral studies.

Extension
If full-time doctoral candidates have not applied to deposit their thesis by the end of the three-year period of study, the academic committee of the programme may authorise an extension of up to one year. In exceptional circumstances, a further one-year extension may be granted, subject to the conditions established by the corresponding doctoral programme. In the case of part-time doctoral candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

Dismissal from the doctoral programme
A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

Enrollment aid

Organization

• Casals Terre, Jasmina

• Casals Terre, Jasmina
• Egusquiza Estevez, Eduard
• Font Llagunes, Josep Maria

• Department of Mechanical Engineering (PROMOTORA)
• Department of Fluid Mechanics
• Terrassa School of Industrial, Aerospace and Audiovisual Engineering

Doctoral Studies Support Unit
Tel.: (+34) 934 016 562

Agreements with other institutions

The research groups and lecturers who are involved in the doctoral programme in Mechanical, Fluids and Aerospace Engineering collaborate with other universities as part of specific doctoral programme or general agreements. The most relevant collaboration agreements are:

Europe:

• École Polytechnique Fédérale de Lausanne (EPFL), Switzerland

• University of Modena & Reggio Emilia (UNIMORE), Italy, Department of Engineering Sciences and Methods in Reggio Emilia.

• – Johannes Kepler University (JKU) in Linz (Austria), Institute of Machine Design and Hydraulic Drives.

• INSA - Toulouse (France), Department of Mechanical Engineering (education) and Institut Clément Ader (research laboratory).

• Lappeenranta University of Technology (LUT, Finland), Department of Mechatronics.

• Luleå Technical University, Department of Engineering Sciences and Mathematics. Divisions: Mechanics of Solid Materials and Fluid and Experimental Mechanics (Sweden), joint supervision of doctoral theses (e.g., Josep Farré Lladós).

• Joint supervision agreement with the Politehnica University of Bucharest (UPB), Romania.
• Faculdade de Engenharia da Universidade do Porto (FEUP), Portugal.

• Department of Sports Performance, INEFC Barcelona, University of Barcelona.

USA:

• University of California, Irvine. Mechanical and Aerospace Engineering Department.

• University of Colorado Boulder, Smead Department of Aerospace Engineering Sciences.

• McGill University, Montreal, Canada.

• Department of Mechanics at the University of Concepción, Chile,

• Department of Electromechanics at the National Technological University, Mendoza Regional Faculty, Argentina.

• EPN, National Polytechnic University, Ecuador.

Asia:

• Khaje Nasir University of Technology, Iran.

• Iran University of Science and Technology, School of Railway Engineering, Tehran, Iran.

• Tsinghua University, Pekin, China.

• Southwest Jiaotong University, Chengdu, Sichuan, China.

• Jiangsu University, China. Currently, two doctoral students with a grant from the China Scholarship Council (CSC) are on our programme: Linlin Geng and Jian Chen.

Africa:

• Abdelmalek Essaâdi University, Tangier, Morocco.

Other collaborations:

A programme lecturer is the scientific coordinator of the European H2020 AFC4Hydro project (https://cordis.europa.eu/project/id/814958). He is responsible for Work Packages WP3 and WP6 (https://afc4hydro.eu/).

A research group from the programme leads the Tailor Project: Personalized Robotic and Neuroprosthetic Modular Wearable Systems for Assistance of Impaired Walking (RTI2018-097290-B) (2019-2021).

Activities in the framework of KIC InnoEnergy:

Since January 2011, lecturers from the doctoral programme have participated in various KIC InnoEnergy projects in areas directly relating to thermal engineering. KIC InnoEnergy SE is a European company that promotes the integration of education, technology, business and entrepreneurship and the strengthening of the culture of innovation, with the strategic objective of become the main driver of innovation in the field of sustainable energy. Lifelong Learning Programme Erasmus Application Form 2012 for Intensive Programmes (IP).

Activities in the context of KIC UrbanMobility:

Since 2019, a research group from the programme has participated actively in EIT Urban Mobility, a European initiative dedicated to accelerating solutions that improve the collective use of urban spaces and ensure their accessibility, safety, efficiency and sustainability with multimodal and economic mobility. Participation in the Antitrush project 2020-2021.

Participation in the Erasmus K103 and K107 programmes by receiving and sending students. For example, Rudi Arief, from the Islamic University of Malaysia, carried out a doctoral research visit in the MicroTech Lab.

Active participation in the Industrial Doctorates Plan: this plan is a strategy of the Government of Catalonia, in collaboration with public and private universities. The aim is to contribute to competitiveness and internationalisation of the Catalan industrial fabric, retain talent and enable doctoral students to develop research, development and innovation projects in a company.

Access profile

Given the multidisciplinary nature of the scientific field of the doctoral programme in Mechanical, Fluids and Aerospace Engineering, there are a wide range of degrees that qualify applicants for admission. The most suitable prior learning for admission corresponds to degrees in engineering and sciences. In the near future, scientific and technological academic backgrounds will be considered suitable. In all cases, students must have completed a master’s degree or 60 ECTS of a master’s degree in subjects relating to the scientific field of the programme.

Access requirements

Applicants must hold a Spanish bachelor’s degree or equivalent and a Spanish master’s degree or equivalent, provided they have completed a minimum of 300 ECTS credits on the two degrees (Royal Decree 43/2015, of 2 February)

In addition, the following may apply:

• Holders of an official degree awarded by a university in Spain or any other country in the European Higher Education Area, pursuant to the provisions of Article 16 of Royal Decree 1393/2007, of 29 October, which establishes official university course regulations, who have completed a minimum of 300 ECTS credits on official university degrees, of which at least 60 must be at the master's degree level.
• Holders of an official Spanish bachelor’s degree comprising at least 300 credits, as provided for by EU regulations. Holder of degrees of this kind must complete bridging courses unless the curriculum of the bachelor’s degree in question included research training credits equivalent in value to those which would be earned on a master's degree.
• Holders of an official university qualification who, having passed the entrance examination for specialised medical training, have completed at least two years of a training course leading to an official degree in a health-sciences specialisation.
• Holders of a degree issued under a foreign education system. In these cases, homologation is not required, but the UPC must verify that the degree certifies a level of training equivalent to an official Spanish master's degree and qualifies the holder for admission to doctoral studies in the country where it was issued. Admission on this basis does not imply homologation of the foreign degree or its recognition for any purpose other than admission to doctoral studies.
• Holders of a Spanish doctoral qualification issued under previous university regulations.

Note 1: Doctoral studies entrance regulations for holders of an undergraduate degree awarded before the introduction of the EHEA (CG 47/02 2014)

Note 2: Governing Council Decision 64/2014, which approves the procedure and criteria for assessing the fulfilment of academic admission requirements for doctoral studies by holders of non-homologated foreign degrees (CG 25/03 2014)

Admission criteria and merits assessment

Doctoral students must be accepted by the academic committee to be able to study on the programme.
To achieve this, students should contact the academic committee and apply according to the procedure established for each programme.

In addition to the admission requirements, the academic committee could establish other conditions for admission to the programme, including passing specific tests.

The admission criteria are based on the academic background of applicants. Specifically, their academic record and university of origin will be assessed according to their potential tutor, associated with the subject area that is initially proposed for the thesis. To facilitate this task, potential applicants should complete some questionnaires and exercises, to give a better idea of their abilities and their likelihood of successfully completing a doctoral degree on these subject areas. The languages used are those of the doctoral programme (Spanish, Catalan and English).

Criteria for assessing merits and weighting:
• Academic record, 30%.
• Personal contact through questionnaires, exercises and telephone interviews, 40%.
• Motivation, 20%.
• Language knowledge, 5%.
• Research experience, 5%.

Training complements

The >academic committee of the programme could ask students to take specific bridging courses. In this case, it will monitor the bridging courses that are taken and establish suitable criteria to limit their duration.

The bridging courses will be on research training, but doctoral students will never be required to enrol for a number of credits equal to or above 60 ECTS. The academic regulations of doctoral studies state that bridging courses may also be cross-disciplinary. However, this point is likely to be amended so that bridging courses are only associated with research credits, particularly when an applicant enters the doctoral programme with a bachelor’s degree worth 300 ECTS.

Considering the doctoral student activity report (DAD), the academic committee of the programme could propose additional measures to those established in the regulations that lead to the withdrawal of doctoral students who do not meet the established criteria.

Procedure to define which bridging courses students should take.
The academic committee will establish the required bridging courses, depending on the student’s prior learning. Likewise, each student will be guided by the thesis tutor(s) and director(s), who will advise them on the most suitable subjects at each point, according to their academic background.

This additional training will consist of passing the corresponding subjects in any of the master’s degrees related to this programme:
• master’s degree in Automatic Control and Robotics
• master’s degree in Industrial Engineering
• master’s degree in Aeronautical Engineering
• master’s degree in Mechanical Engineering
• master’s degree in Biomedical Engineering

Enrolment period for new doctoral students

The enrolment period for new doctoral students will be in September.

More information at the registration section for new doctoral students

Enrolment period

After the first year, the enrolment period for doctoral students will run from September to mid-October.

More information at the general registration section

Procedure for the preparation and defense of the research plan

Doctoral candidates must submit a research plan, which will be included in their doctoral student activity report, before the end of the first year. The plan may be improved over the course of the doctoral degree. It must be endorsed by the tutor and the supervisor, and it must include the method that is to be followed and the aims of the research.

At least one of these annual assessments will include a public presentation and defence of the research plan and work done before a committee composed of three doctoral degree holders, which will be conducted in the manner determined by each academic committee. The examination committee awards a Pass or Fail mark. A Pass mark is a prerequisite for continuing on the doctoral programme. Doctoral candidates awarded a Fail mark must submit a new research plan for assessment by the academic committee of the doctoral programme within six months.

The committee assesses the research plan every year, in addition to all of the other activities in the doctoral student activity report. Doctoral candidates who are awarded two consecutive Fail marks for the research plan will be obliged to definitely withdraw from the programme.

If they change the subject of their thesis, they must submit a new research plan.

Formation activities

Activity: Tutorial.
Hours: 288

Procedure for assignment of tutor and thesis director

The academic committee of the doctoral programme assigns a thesis supervisor to each doctoral candidate when they are admitted or enrol for the first time, taking account of the thesis supervision commitment referred to in the admission decision.

The thesis supervisor will ensure that training activities carried out by the doctoral candidate are coherent and suitable, and that the topic of the candidate’s doctoral thesis will have an impact and make a novel contribution to knowledge in the relevant field. The thesis supervisor will also guide the doctoral candidate in planning the thesis and, if necessary, tailoring it to any other projects or activities undertaken. The thesis supervisor will generally be a UPC professor or researcher who holds a doctoral degree and has documented research experience. This includes PhD-holding staff at associated schools (as determined by the Governing Council) and UPC-affiliated research institutes (in accordance with corresponding collaboration and affiliation agreements). When thesis supervisors are UPC staff members, they also act as the doctoral candidate’s tutor.

PhD holders who do not meet these criteria (as a result of their contractual relationship or the nature of the institution to which they are attached) must be approved by the UPC Doctoral School's Standing Committee in order to participate in a doctoral programme as researchers with documented research experience.

The academic committee of the doctoral programme may approve the appointment of a PhD-holding expert who is not a UPC staff member as a candidate’s thesis supervisor. In such cases, the prior authorisation of the UPC Doctoral School's Standing Committee is required. A UPC staff member who holds a doctoral degree and has documented research experience must also be proposed to act as a co-supervisor, or as the doctoral candidate’s tutor if one has not been assigned.

A thesis supervisor may step down from this role if there are justified reasons (recognised as valid by the committee) for doing so. If this occurs, the academic committee of the doctoral programme will assign the doctoral candidate a new thesis supervisor.

Provided there are justified reasons for doing so, and after hearing any relevant input from the doctoral candidate, the academic committee of the doctoral programme may assign a new thesis supervisor at any time during the period of doctoral study.

If there are academic reasons for doing so (an interdisciplinary topic, joint or international programmes, etc.) and the academic committee of the programme gives its approval, an additional thesis supervisor may be assigned. Supervisors and co-supervisors have the same responsibilities and academic recognition.

The maximum number of supervisors of a doctoral thesis is two: a supervisor and a co-supervisor.

For theses carried out under a cotutelle agreement or as part of an Industrial Doctorate, if necessary and if the agreement foresees it this maximum number of supervisors may not apply. This notwithstanding, the maximum number of supervisors belonging to the UPC is two.

More information at the PhD theses section

Permanence

The academic committee of the programme may authorise an extension of up to one year for full-time doctoral candidates who have not applied to deposit their thesis by the end of the three-year period of study, in the terms outlined in the Academic Regulations for Doctoral Studies of the Universitat Politècnica de Catalunya. In the case of part-time candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

International Mention

The doctoral degree certificate may include International Doctorate mention. In this case, the doctoral candidate must meet the following requirements:

a) During the period of study leading to the award of the doctoral degree, the doctoral candidate must have spent at least three months at a respected higher education institution or research centre outside Spain to complete courses or do research work. The stays and activities carried out must be endorsed by the thesis supervisor and authorised by the academic committee of the programme. The candidate must provide a certifying document issued by the person responsible for the research group of the body or bodies where the stay or activity was completed. This information will be added to the doctoral student’s activity report.
b) Part of the thesis (at least the summary and conclusions) must be written and presented in one of the languages commonly used for science communication in the relevant field of knowledge, which must not be an official language of Spain. This rule does not apply to stays and reports in Spanish or to experts from Spanish-speaking countries.
c) At least two PhD-holding experts belonging to a higher education institution or research centre outside Spain must have issued officially certified reports on the thesis.
d) The thesis examination committee must have included at least one PhD-holding expert from a higher education or research institution outside Spain who was not responsible for the candidate’s stay abroad (point a) above).
e) The thesis defence must have taken place on UPC premises or, in the case of joint programmes, at the location specified in the collaboration agreement.

List of authorized thesis for defense

Last update: 25/02/2021 06:02:50.

List of lodged theses

• SARABANDI, SOHEIL: Solving the Nearest Rotation Matrix Problem in Three and Four Dimensions with Applications in Robotics
  
  Author: SARABANDI, SOHEIL
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Institute of Robotics and Industrial Informatics (IRI)
  Mode: Normal
  Deposit date: 19/02/2021
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: THOMAS ARROYO, FEDERICO
  Committee:
       PRESIDENT: OTTAVIANO, ERIKA
       SECRETARI: ROS GIRALT, LLUIS
       VOCAL: SALTARÉN PAZMIÑO, ROQUE JACINTO
  Thesis abstract: Since the map from quaternions to rotation matrices is a 2-to-1 covering map, this map cannot be smoothly inverted. As a consequence, it is sometimes erroneously assumed that all inversions should necessarily contain singularities that arise in the form of quotients where the divisor can be arbitrarily small. This misconception was clarified when we found a new division-free conversion method. This result triggered the research work presented in this thesis. At first glance, the matrix to quaternion conversion does not seem to be a relevant problem. Actually, most researchers consider it as a well-solved problem whose revision is not likely to provide any new insight in any area of practical interest. Nevertheless, we show in this thesis how solving the nearest rotation matrix problem in Frobenius norm can be reduced to a matrix to quaternion conversion. Many problems, such as hand-eye calibration, camera pose estimation, location recognition, image stitching etc. require finding the nearest proper orthogonal matrix to a given matrix. Thus, the matrix to quaternion conversion becomes of paramount importance. While a rotation in 3D can be represented using a quaternion, a rotation in 4D can be represented using a double quaternion. As a consequence, the computation of the nearest rotation matrix in 4D, using our approach, essentially follow the same steps as in the 3D case. Although the 4D case might seem of theoretical interest only, we show in this thesis its practical relevance thanks to a little known mapping between 3D displacements and 4D rotations. In this thesis we focus our attention in obtaining closed-form solutions, in particular those that only require the four basic arithmetic operations because they can easily be implemented on microcomputers with limited computational resources. Moreover, closed-form methods are preferable for at least two reasons: they provide the most meaningful answer because they permit analyzing the influence of each variable on the result; and their computational cost, in terms of arithmetic operations, is fixed and assessable beforehand. We have actually derived closed-form methods specifically tailored for solving the hand-eye calibration and the pointcloud registration problems which outperform all previous approaches.
  

Last update: 25/02/2021 06:02:13.

List of defended theses by year

• ALGAR ESPEJO, ANTONIO: Amortiguación de final de carrera de actuadores hidráulicos
  
  Author: ALGAR ESPEJO, ANTONIO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Fluid Mechanics (MF)
  Mode: Temporary seizure
  Reading date: 08/02/2021
  Thesis director: CODINA MACIA, ESTEBAN | FREIRE VENEGAS, FRANCISCO JAVIER
  

  Committee:
       PRESIDENT: GAMEZ MONTERO, PEDRO JAVIER
       SECRETARI: VERNET PEÑA, ANTONIO
       VOCAL: ROCA ENRICH, JOAN
  Thesis abstract: The internal cushioning systems of hydraulic linear actuators, of special interest in mobile machinery, pursue to avoid mechanical shocks at their end of stroke. The design where the piston, with perimeter grooves, regulates the flow by standing in front of the outlet port has not been studied in depth until now. Consequently, the operating fundamentals, influencing factors and optimization of these cushioning designs have been investigated. First, a dynamic model has been developed using the bond graph technique that integrates the mechanical equations of the actuator, the hydraulic circuit and the flow through the studied internal cushion design. This considers the evolution of internal flow during cushioning, characterized in detail by fluid-dynamic simulation. This CFD model has been validated experimentally for its refinement and well-founded determination of discharge coefficients. Subsequently, the complete dynamics of the actuator and, in particular, the radial movement of the piston are experimentally studied by means of the difficult installation of a sophisticated displacement sensor. Finally, the experimental observations and the fluid-dynamic coefficients are integrated into the dynamic model; ultimately, the model aims to predict the experimental behavior of the cushioning during the movement of the arm of an excavator. The radial movement of the observed piston turns it into an active and adjusting element that is essential in cushioning. This radial movement in coherence with the significant drag force estimated in the CFD simulation, generated by the flow through the grooves, where the laminar flow regime predominates. Analytical models are suitable for predicting the behavior of the cushioning system, observing results comparable to those experimentally obtained . There is an optimal behavior, highly influenced by the mechanical stress conditions of the system, subject to a compromise between an increasing section of the grooves and an optimization of the radial gap. In addition, given the difficult direct measurement of the radial movement of the piston, an indirect measurement method has been evaluated using low-cost accelerometers. Thus, a bond graph simulation model predicts the results of the double integration of acceleration, observed experimentally. Influenced by the diverse nature of the existing movements, the severe propagation of measurement errors makes indirect measurement of piston radial motion inadequate.
  

• BELLAFONT PERALTA, IGNASI: Study of the beam induced vacuum effects in the cryogenic beam vacuum chamber of the Future Circular Hadron Collider
  
  Author: BELLAFONT PERALTA, IGNASI
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Fluid Mechanics (MF)
  Mode: Normal
  Reading date: 25/01/2021
  Thesis director: ESCALER PUIGORIOL, FRANCESC XAVIER | QUISPE FLORES, MARCOS OSWALDO
  

  Committee:
       PRESIDENT: PONT, MONTSERRAT
       SECRETARI: KOUBYCHINE MERKULOV, YOURI ALEXANDROVICH
       VOCAL: FERREIRA SOMOZA, JOSE ANTONIO
  Thesis abstract: The Future Circular Hadron Collider (FCC-hh) is a proposal for a 100 km long hadron collider conceived as the successor of the Large Hadron Collider (LHC). The FCC-hh is designed to reach 50 TeV of beam energy, greatly surpassing the current energy frontier set by the LHC at 7 TeV. Thus, it is expected to expand the current horizon of understanding of the Standard Model of particle physics. The beam vacuum chamber of the FCC-hh will have to cope with unprecedented levels of synchrotron radiation power for hadron colliders, around 160 times higher than its predecessor, dealing simultaneously with a tighter magnet aperture. Since the higher radiation power will result in a much higher gas load, the difficulty to achieve a good vacuum quality increases considerably compared with the LHC. This thesis presents a study of the so-called beam induced vacuum effects in the FCC-hh, meaning the different phenomena which, due to the presence of the particle beam, have a detrimental impact on the accelerator¿s vacuum level. These studied effects are the photon stimulated desorption (PSD), the electron stimulated desorption (ESD) and ion stimulated desorption (ISD). Each effect has been thoroughly studied, calculating analytically and with a series of Monte Carlo simulations the resulting gas density in the chamber for all the common gas species. Finally, the feasibility of the FCC-hh from the vacuum point of view has been assessed. To mitigate the beam induced effects and to improve the vacuum quality in the FCC-hh (essential for a proper machine operation) it was necessary to propose a new beam screen design. The new beam screen features new solutions to mitigate the e- cloud, to handle the synchrotron radiation and a much higher pumping speed, at the expense of a higher manufacturing complexity. A dedicated experimental setup was used by CERN during the design phase to measure the vacuum performance of the developed beam screen prototypes. Finally, the obtained experimental results were compared with the theoretical results to further enhance their validity. It is concluded that thanks to the new beam screen design, the vacuum level in the FCC-hh should be adequate. Using nominal beam parameters, the established FCC-hh vacuum specifications could be met within the first months of conditioning, a reasonable amount of time.
  

• GARCIA VILANA, SILVIA: Modelo estocástico de hueso cortical de costilla humana para la predicción de fracturas mediante emisión acústica
  
  Author: GARCIA VILANA, SILVIA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Strength of Materials and Structural Engineering (RMEE)
  Mode: Normal
  Reading date: 04/02/2021
  Thesis director: SÁNCHEZ MOLINA, DAVID | VELAZQUEZ AMEIJIDE, JUAN
  

  Committee:
       PRESIDENT: GIL MUR, FRANCISCO JAVIER
       SECRETARI: DI CAPUA, DANIEL
       VOCAL: GARCIA GRANADA, ANDRES AMADOR
  Thesis abstract: In this document, a non-linear constitutive model with micro-cracking and irreversibility is proposed for cortical bone of the human rib, extended with a stochastic fracture model, based on acoustic emission. Both models are innovative and describe the behavior of the human rib from the zero-load to macroscopic fracture. Experimentally, the models have shown to describe adequately the mechanical behavior of the rib, even in the non-elastic zone, where irreversible processes have been mainly associated with the propagation of micro-cracks through the material. Furthermore, the constitutive model is thermodynamically consistent, showing a notable increase in entropy as cracking process goes on, a region in which, in turn, a notable asymptotic increase in the released energy by the material has been observed in the form of waves, detected by the acoustic emission technique.In addition, the constitutive parameters of the model show significant correlation both with anthropometric variables and with micro-structural parameters, such as density, fractal dimension or mineral content, pointing to a clear importance of micro-structure in the behavior of cortical bone. Thus, the quenched disorder parameter, which represents the micro-structural damage previous to failure and which has been introduced into the model by means of the Statistical Mechanics, has shown to have a great influence of age. Likewise, a relationship has also been found between the mineralization of the sample and the possible paths that the main crack can take in its progression through the osteon network. The number of paths has been determined by means of combinatorics.On the other hand, the stochastic fracture model adequately and quantitatively predicts the occurrence of acoustic signals or hits associated with the stress level introduced into the sample, being one of the first models developed for bone.
  

• GENG, LINLIN: Numerical Investigation and Modelling of the Unsteady Behavior and Erosion Power of Cloud Cavitation
  
  Author: GENG, LINLIN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Fluid Mechanics (MF)
  Mode: Article-based thesis
  Reading date: 28/01/2021
  Thesis director: ESCALER PUIGORIOL, FRANCESC XAVIER
  

  Committee:
       PRESIDENT: FARHAT, MOHAMED
       SECRETARI: GUARDO ZABALETA, ALFREDO DE JESUS
       VOCAL: HUANG, XINGXING
  Thesis abstract: Cloud cavitation is a unwanted phenomenon taking place in many hydraulic machines which damages the surfaces of the solid walls due to the erosive aggressiveness induced by the collapse process. Therefore, it is necessary to accurately predict the occurrence of cloud cavitation and quantify its erosion intensity to improve the design and to extend the life cycle of existing machines and systems. The application of numerical simulation (CFD) offers the opportunity to predict unsteady cavitation. For that, it is of paramount importance to investigate how to select the most appropriate models to obtain more accurate results in an efficient way and how to relate the collapsing vapor structures with their erosion power. In the current study, the influence of the different turbulence models was assessed and the performance of cavitation models was improved. The relationship between the unsteady behavior and its erosion character was also considered by implementing an erosion model.For the assessment of the turbulence models, three Unsteady Reynolds Average Navier-Stokes (URANS) turbulence models were employed to simulate the cloud cavitation around a NACA65012 hydrofoil at eight different hydrodynamic conditions. The results indicate that the Shear Stress Transport (SST) model can better capture the unsteady cavity behavior than the k-e and the RNG models if the near wall grid resolution is fine enough. For the improvement of the cavitation models, the influence of the empirical constants of the Zwart model on the cavity dynamics was firstly investigated. The results show that the cavity behavior is sensitive to their variation, and thereby an optimal range is proposed which can provide a better prediction of the vapor volume fraction and of the instantaneous pressure pulse generated by the main cloud cavity collapse. Secondly, the original Zwart and Singhal cavitation models were corrected by taking into account the second order term of the Rayleigh-Plesset equation. The performances of the original and corrected models were compared for two different cavitation patterns. The results for a steady attached cavity demonstrate that the corrected model predicts better the pressure distribution at the cavity closure region and the cavity length in comparison with the experiment observations. The results for unsteady cloud cavitation also confirm that the prediction of the shedding frequency can be improved with the corrected Zwart model.For the investigation of the cavitation erosion power, an erosion model based on the energy balance approach was employed. It has been found that the spatial and temporal distribution of the erosion aggressiveness is sensitive to the selection of the cavitation model and to the collapse driving pressure. In particular, the use of average pressure levels combined with the Sauer cavitation model permit to achieve reliable results. Then, two erosion mechanisms have been observed, one occurs at the closure region of the main sheet cavity characterized by low-intensity collapses but with high frequency, and the other is inducted by the collapse of the shed cloudy cavity which presents a high erosion intensity but with low frequency. Finally, it has been found that the erosion power follows a power law with the main flow velocity with exponents ranging from 3 to 5 depending on the erosion estimate being used.
  

• RALLO TOLÓS, HÉCTOR: Second Life Batteries of Electric Vehicles: Analysis of Use and Management Models
  
  Author: RALLO TOLÓS, HÉCTOR
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Project and Construction Engineering (EPC)
  Mode: Normal
  Reading date: 09/02/2021
  Thesis director: AMANTE GARCIA, BEATRIZ
  

  Committee:
       PRESIDENT: VILANOVA ARBOS, RAMON
       SECRETARI: AUGER, DANIEL J.
       VOCAL: KNAP, VÁCLAV
  Thesis abstract: The mobility of the future undoubtedly involves the electrification of vehicles. The increase in social awareness towards a reduction in CO2 emissions, together with the introduction of new laws regulating them, has finally led to an increase in the sales of electric vehicles. Furthermore, this trend is expected to continue to increase due to the global interest in reducing these emissions.The growth in sales has meant that lithium-ion batteries have become an indispensable element in the automotive sector. The overall emissions of an electric car are between 20 and 40 % lower than those of conventional vehicles, with the current energy mix. With the increase in green power generation, the EU expects to reduce emissions by up to 75 % by 2050 compared to fossil fuel vehicles.The battery, like any other vehicle component, wears out over time and use. Car manufacturers recommend that when these batteries reach 70 % of their health, they should be replaced, as the manufacturers cannot guarantee their proper functioning and they could suffer a drastic drop in capacity, i.e. in the vehicle's range.However, before these batteries are recycled, there is a possibility that they could be reused, as they still have enough power and capacity, to be used in other, less demanding applications. As a result, the reuse of these batteries, whose cost represents between 30 and 40 % of the final price of an electric vehicle, is seen within the automotive sector as a great possibility to reduce the selling price of the electric car and make it more competitive than internal combustion cars.Batteries have therefore become an indispensable element not only for the automotive industry, but also for any application that needs to store electrical energy. Consequently, it is already suggested that there is a market niche where these batteries could have great potential. The objective of reducing the heavy dependence on fossil fuels has led to an increase in renewable energies in the European energy mix. Their intermittence opens the door for energy storage sources to cover the moments when there is no generation.Giving a second life to electric vehicle batteries has prompted the research interest of this doctoral thesis, which analyses different new models of use and business once they are no longer valid for the automobile.
  

Last update: 25/02/2021 06:01:57.

Research groups

• BIOMEC-Biomechanical Engineering Lab
• CDEI-DM-Center for Industrial Equipment Design
• CDIF-Center for Industrial Diagnostics
• CRnE-Barcelona Research Center in Multiscale Science and Engineering
• LABSON-Fluid power systems laboratory
• LEAM-Acoustic and Mechanical Engineering Laboratory
• LITEM-Materials and Structures Laboratory of Innovation Technology
• MICROTECH LAB-Microtechnology for the Industry
• TECNOFAB-Manufacturing Technologies Research Group
• TUAREG-Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group

Teachers

• Bergadà Granyó, Josep Maria
• Buj Corral, Irene
• Cante Teran, Juan Carlos
• Casals Terre, Jasmina
• Castilla Lopez, Roberto
• Codina Macia, Esteban
• Egusquiza Estevez, Eduard
• Escaler Puigoriol, Xavier
• Font Llagunes, Josep Maria
• Gamez Montero, Pedro Javier
• Gil Espert, Lluis
• Guardo Zabaleta, Alfredo
• Romeu Garbi, Jordi
• Soria Guerrero, Manel
• Travieso Rodriguez, Jose Antonio
• Valero Ferrando, Mª del Carmen

• Alvarez del Castillo, Javier
• Amante Garcia, Beatriz
• Arcos Villamarin, Robert
• Balastegui Manso, Andreu
• de las Heras Jimenez, Salvador
• Flores Le Roux, Roberto Maurice
• Freire Venegas, Francisco Javier
• Goma Ayats, Juan Ramon
• Gonzalez Rojas, Hernan Alberto
• Hernandez Ortega, Joaquin
• Hutchinson, John M.
• Jordi Nebot, Lluïsa
• Lloberas Valls, Oriol
• Martinez Miralles, Jordi Ramon
• Minguella Canela, Joaquim
• Ortega, Enrique
• Pamies Gomez, Teresa
• Pamies Vila, Rosa
• Porta Pleite, Jose Maria
• Romeral Martinez, J.L.
• Ros Giralt, Lluis
• Salan Ballesteros, M. Núria
• Sanchez Romero, Montserrat
• Santos Lopez, M. Antonia de los
• Veciana Fontanet, Joaquim Maria
• Weyler Perez, Rafael