Timea Bejat

Dr. Timea Bejat

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2017 in Construction and Building Materials
Verified
Journal Article
Closed access
APA. Piot
A. Piot
TBTimea Bejat
Timea Bejat
AJA. Jay
A. Jay
LBL. Bessette
L. Bessette
EWE. Wurtz
E. Wurtz
LBL. Barnes-Davin
L. Barnes-Davin

15 April 2021 in Energies
Verified
Journal Article
Open access
PDF file
NSNayara Rodrigues Marques Sakiyama
Nayara Rodrigues Marques Sakiyama
JFJuergen Frick
Juergen Frick
TBTimea Bejat
Timea Bejat
HGHarald Garrecht
Harald Garrecht
Predicting building air change rates is a challenge for designers seeking to deal with natural ventilation, a more and more popular passive strategy. Among the methods available for this task, computational fluid dynamics (CFD) appears the most compelling, in ascending use. However, CFD simulations require a range of settings and skills that inhibit its wide application. With the primary goal of providing a pragmatic CFD application to promote wind-driven ventilation assessments at the design phase, this paper presents a study that investigates natural ventilation integrating 3D parametric modeling and CFD. From pre- to post-processing, the workflow addresses all simulation steps: geometry and weather definition, including incident wind directions, a model set up, control, results’ edition, and visualization. Both indoor air velocities and air change rates (ACH) were calculated within the procedure, which used a test house and air measurements as a reference. The study explores alternatives in the 3D design platform’s frame to display and compute ACH and parametrically generate surfaces where air velocities are computed. The paper also discusses the effectiveness of the reference building’s natural ventilation by analyzing the CFD outputs. The proposed approach assists the practical use of CFD by designers, providing detailed information about the numerical model, as well as enabling the means to generate the cases, visualize, and post-process the results.

1 February 2017 in Chemical Engineering Research and Design
Verified
Journal Article
Closed access
MOMichel Ondarts
Michel Ondarts
WHWafa Hajji
Wafa Hajji
JOJonathan Outin
Jonathan Outin
TBTimea Bejat
Timea Bejat
EGEvelyne Gonze
Evelyne Gonze

2 January 2015 in Journal of Building Performance Simulation
Verified
Journal Article
Closed access
Simon RouchierSimon Rouchier
Simon Rouchier
MWMonika Woloszyn
Monika Woloszyn
YKYannick Kedowide
Yannick Kedowide
TBTimea Bejat
Timea Bejat
This paper proposes the application of the covariance matrix adaptation (CMA) evolution strategy for the identification of building envelope materials hygrothermal properties. All material properties are estimated on the basis of local temperature and relative humidity measurements, by solving the inverse heat and moisture transfer problem. The applicability of the identification procedure is demonstrated in two stages: first, a numerical benchmark is developed and used as to show the potential identification accuracy, justify the choice for a Tikhonov regularization term in the fitness evaluation, and propose a method for its appropriate tuning. Then, the procedure is applied on the basis of experimental measurements from an instrumented test cell, and compared to the experimental characterization of the observed material. Results show that an accurate estimation of all hygrothermal properties of a building material is feasible, if the objective function of the inverse problem is carefully defined.

26 January 2024 in Solar Energy Materials and Solar Cells
Verified
Journal Article
Closed access
MPMargot Landa - Pliquet
Margot Landa - Pliquet
TBTimea Bejat
Timea Bejat
MSMarion Serasset
Marion Serasset
ADAxel Descormes
Axel Descormes
EMEeva Mofakhami
Eeva Mofakhami
EVEszter Voroshazi
Eszter Voroshazi

11 April 2024 in Progress in Photovoltaics: Research and Applications
Verified
Journal Article
Open access
PDF file
TBTimea Bejat
Timea Bejat
NGNouha Gazbour
Nouha Gazbour
ABAmandine Boulanger
Amandine Boulanger
RMRémi Monna
Rémi Monna
RVRenaud Varache
Renaud Varache
EVEszter Voroshazi
Eszter Voroshazi
The photovoltaic (PV) industry is reaching an inflection point to become a major source of energy. Last decades brought important technical progression in modules' yield and durability. Already available technical solutions might reach the highest power output and the lowest environmental impact in a module. Nevertheless, cost remains the major driver for innovation; top PV panels must combine cost/delay/yield to reach reasonable market share. Our paper presents the development of silicon heterojunction (SHJ) modules with exemplary power and reliability with significantly reduced environmental impact and components sourced from Europe. In order to guide the technology choice in the design phase, we performed a Life Cycle Assessment (LCA) sensitivity study. For a standard PV module, we identify the main steps to improve in order to reduce its environmental footprint. This guided us to tackle the components with the highest impact on the carbon footprint, namely the wafer, glass front sheet and aluminium frame. The proposed improvements will be tested from technical and economic point of view and assembled within one PV module. At the cell scale, we achieved the reduction of the carbon footprint by reducing the thickness of the wafers issued from the European value chain. Optimisation of metallisation and cell interconnection has limited the consumption of silver (Ag), a critical raw metal. At the module level, we implemented the reduction of glass thickness and the replacement of the aluminium frame with a natural fibre‐based frame in a glass‐backsheet module configuration. In addition, we applied a ‘design for recycling’ approach for the choice of encapsulant and backsheet. The combination of these innovations led us to the realisation of a 566‐Wp recyclable module using a tiling interconnection, cells with an average efficiency of 22.57% with a carbon footprint of 313 kgCO2eq/kWp.