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Refet Yalçin
Researcher
Engineer

Refet Yalçin

My goal is to orientate my research to address the common problems of humanity such as global warming, energy efficiency and food. My research is based on radiative heat transfer and photonics. Application fields include but are not limited to improving thermal efficiencies of the structures to engineer sustainable - green buildings, improving crop growth of greenhouses by altering solar spectrum using fluorescent greenhouse coatings, improving thermal insulation by IR opacification from very low (cryogenic, liquid hydrogen storage) to very high (thermal runaway in batteries) temperature applications.

I had my PhD degree in Mechanical Engineering from Bogazici University. I came to Institut Pprime, France in 2019 as a CNRS researcher. I won two prestigious fellowships. With the Fulbright fellowship I went to UCLA, Los Angeles in the beginning of 2021 for about a year as a visiting scholar. Then, with the MSCA Individual Fellowship I returned to France at the end of 2021. I've joined Saint-Gobain research in 2022 and am currently conducting my research here. At present, I have 20 published papers in SCIE indexed peer-reviewed journals, 1 published patent along with several patents and publications in the pipeline.

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What I Do

Design metamaterials

- Design metamaterials at the nanoscale to control EM wave and radiation transfer for energy applications
- Understand material and EM wave interaction and structure/property relationship

Green & sustainable buildings

I design window glasses with better thermal efficiency without sacrificing visual comfort. I also design coatings for buildings which can cool below ambient temperature even under direct sunlight. This is possible thanks to the radiative cooling which is a passive cooling method that does not consume energy.

How I do

- Perform state-of-the-art numerical simulations on scientific computing clusters and clouds.
- Perform simple experiments or collaborate with experimentalists

Solar energy

Maximise absorbed solar energy by desiging low-cost pigmented coatings (paints)

Greenhouses

I design fluorescent coatings for greenhouses to improve the crop by improving usable light for photosynthesis. The idea is to use phosphors to shift the green spectrum to the red one in the solar intensity.

Quotes

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful. If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living.

Henri Poincaré

Henri Poincaré

Who is more humble? The scientist who looks at the universe with an open mind and accepts whatever the universe has to teach us, or somebody who says everything in this book must be considered the literal truth and never mind the fallibility of all the human beings involved

Carl Sagan

Carl Sagan

Resume

Experience

2022 - ongoing
Saint-Gobain Research

Research engineer

  • Engineering IR opacifiers for insulation pads to avoid thermal runaway in electric vehicle batteries.
  • Thermal modelization of paint drying & curing in a mirror line that involves IR heaters.
  • Reducing urban heat island effects.
  • Radiative cooling material development, characterization and thermal/optical measurements.
  • Calculating buildings' energy consumption using Energy+ to identify effect of materials on energy consumption.
  • Improving thermal insulation of fibrous materials for cryogenic applications
2021 - 2022
ENSIP / Université de Poitiers

Marie Sklodowska Curie fellow

Using nano-antennas to alter emission direction of the phosphor particles in semi-transparent greenhouse coatings with near-field radiation to enhance photosynthesis thus plant growth in greenhouses.

2020 - 2021
University of California, Los Angeles (UCLA)

Fulbright visiting scholar

  • Solving dense medium radiative transfer in porous medium (silica aerogel). Validating the model by preparing, characterizing and measuring the thermal and optical performance of the colloids.
  • Solving absorption cross section of large photosynthetic cell ensembles (volvox). I leased and used a supercomputer from MS Azure with 3.6 TB of RAM to use the T-matrix method to solve a 60 micrometer sized volvox cell ensemble under visible light.
  • Co-advising undergraduate and graduate students on dense medium radiative transfer projects (ongoing).
2019 - 2020
CNRS / Institut Pprime

Postdoctoral researcher

  • Modeling and optimization of radiative cooling by using nano fibers. Analytical solution of scattering by a cylinder is used in conjunction with 3D Monte Carlo method to solve radiative transfer equation.
  • Obtaining colorful radiative cooling coatings by using plain and core-shell nanoparticles, nano-layers and phosphor particles. Fabricationg colored radiative coolers by  sputtering silver NPs.
2018 - 2019
Sabanci University

Postdoctoral researcher

Optical and thermal design of thin coatings using thermochromic vanadium dioxide. Fabricating the coating with electron beam evaporation and annealing. Digitizing the SEM image of pigmented coating and solving EM wave interaction using discrete dipole approximation and validate the method with spectroscopic ellipsometry data.

2012 - 2018
Bogazici University

Research & teaching assistant

Research:

  • Global optimization of solar thermal collectors' spectrally selective coatings. Used methods: Metahuristic
    optimization, tabu search, simulated annealing, four-flux method, Mie scattering, the T-Matrix method.
  • Improve of crops in greenhouses by altering the spectrum of sunlight using phosphor particles in greenhouse coating.

Teaching assistant of:

  • Undergraduate Level: Computer applications in mechanical eng, thermodynamics I-II, heat transfer, design of thermal systems.
  • Graduate Level: Advanced fluid dynamics, conduction heat transfer, convection heat transfer, radiative heat transfer.

Education

2012 - 2018
Bogazici University

Mechanical engineering

Doctor of philosophy (PhD)
Improve of crops in greenhouses by altering the spectrum of sunlight using phosphor particles in greenhouse coating.

2009 - 2012
Bogazici University

Mechanical engineering

Master of science (MSc.)
Global optimization of solar thermal collectors' spectrally selective coatings by solving inverse problem.

2004 - 2009
Middle East Technical University

Mechanical engineering

Bachelor of science (B.Sc)
Thermodynamics, heat transfer, renewable energy.

Publications in peer-reviewed scientific journals (SCIE)

  1. Kaya A, Erturk H, Yalcin RA, "Energy efficiency of solar illuminated vertical farms with different illumination strategies", Energy, 307, 2024. DOI: 10.1016/j.energy.2024.132609.
  2. Bhanawat A, Martinez R, Yalcin RA, Lee T, Pilon L, "Dependent scattering and plasmon coupling in concentrated suspensions of optically hard nanoparticles", Applied Physics Letters, 125, 2024, DOI: 10.1063/5.0192977.
  3. Martinez R, Bhanawat A, Yalcin RA, Pilon L, "The transparency of nanoemulsions is due to dependent scattering", J. Phys. Chem. C, 2024, DOI: 10.1021/acs.jpcc.3c08072.
  4. Taufiq A, Erturk H, Yalcin RA, "Revisiting the scattering regime map based on transport scattering coefficient for dielectric particulate medium", Int. Commun. Heat Mass Transf., 154, 2024, DOI: 10.1016/j.icheatmasstransfer.2024.107387.
  5. Taufiq A, Erturk H, Yalcin RA, "Evaluation of methods and metrics for identifying scattering regime of dielectric particulate medium", Int. Commun. Heat Mass Transf., 154, 2024, DOI: 10.1016/j.icheatmasstransfer.2024.107386.
  6. Yalcin RA, Haratoka C, Babonneau D, Camelio S, Joulain K, Drevillon J, "The effect of size and shape-dependent optical properties on colored radiative cooling in metal island films", J. Quant. Spectrosc. Radiat. Transf., 312, 2024, DOI: 10.1016/j.jqsrt.2023.108797.
  7. Abhinav B, Yalcin RA, Martinez R, Pilon L, "Critical review and experimental validation of radiative transfer models for semitransparent media containing large gas bubbles", J. Quant. Spectrosc. Radiat. Transf., 311, 2023, DOI: 10.1016/j.jqsrt.2023.108781.
  8. Hoeniges J, Yalcin RA, Bhowmik A, Partusch VJ and Pilon L, "Light absorption by Volvocaceae consisting of ordered optically soft photosynthetic cells", Algal Research, 72, 2023, DOI: 10.1016/j.algal.2023.103082.
  9. Haratoka C, Yalcin RA, Erturk H, "Examination of energy and visual comfort performance of thermo-chromic coatings for cellular offices", Energy, 267, 2023, DOI: 10.1016/j.energy.2022.126517.
  10. Yalcin RA, Markkanen J, Tolbert S, Pilon L, "Radiative transfer with reciprocal transaction method to account for dependent scattering in thick and concentrated colloidal suspensions", ACS Photonics, 9, 2022, DOI: 10.1021/acsphotonics.2c00664.
  11. Haratoka C, Yalcin RA, Erturk H, "Design of thermo-chromic glazing windows considering energy consumption and visual comfort for cellular offices", Solar Energy, 241, 2022, DOI: 10.1016/j.solener.2022.06.025.
  12. Yalcin RA, Erturk H, "Monte Carlo method solution of the broadband fluorescent radiative transfer equation considering fluorescent cascade", Applied Optics, 60, 2021, DOI: 10.1364/AO.410325.
  13. Yalcin RA, Blandre E, Joulain K and Drevillon J, "Colored radiative cooling coatings with fluorescence", Journal of Photonics for Energy, 11, 2021, DOI: 10.1117/1.JPE.11.032104. Featured on the journal's front cover.
  14. Blandre E, Yalcin RA, Joulain K and Drevillon J, "Microstructured surfaces for colored and non-colored sky radiative cooling", Optics Express, 28, 2020, DOI: 10.1364/OE.401368.
  15. Yalcin RA, Blandre E, Joulain K and Drevillon J, "Colored radiative cooling coatings with nanoparticles", ACS Photonics, 7, 2020, DOI: 10.1021/acsphotonics.0c00513.
  16. Yalcin RA, Erturk H, "Improving crop production in solar illuminated vertical farms using fluorescence coatings", Biosystems Engineering, 193, 2020, DOI: 10.1016/j.biosystemseng.2020.02.007.
  17. Yalcin RA, Blandre E, Joulain K and Drevillon J, "Daytime radiative cooling with silica fiber network", Sol. Energy Mater Sol. Cells, 206, 2020, DOI: 10.1016/j.solmat.2019.110320.
  18. Yalcin RA, Erturk H, "Improving photosynthetic efficiency using greenhouse coatings with scattering and fluorescent pigments", Mater. Res. Express, 6, 2019, DOI: 10.1088/2053-1591/ab28b8.
  19. Uslu M, Yalcin RA, Misirlioglu B, Sendur K, "Spectral reflectance lineshapes as a measure of morphology of VO2 thin films", J. Appl. Phys., 125, 2019, DOI: 10.1063/1.5086272.
  20. Yalcin RA, Ertürk H, "Inverse design of spectrally selective thickness sensitive pigmented coatings for solar thermal applications", Journal of Solar Energy Engineering, 140, 2018, DOI: 10.1115/1.4039276.

Language Skills

English

French

Job related skills

Radiative heat transfer

Conductive heat transfer

Convective heat transfer

Fluid mechanics

Local and global optimization

Electromagnetics

Finite element methods (FEM)

Finite difference time domain (FDTD)

Fluorescence in absorbing and scattering media

Thin film coatings

Plasmonics, nano-antennas

Monte carlo ray tracing

Coding Skills

MATLAB

Python

Fortran

C

ANSYS Lumerical

COMSOL

SQL

ASP / VBScript

.NET

PHP

HTML / CSS

Javascript

Gallery

Photos and videos
Family

Family

Family
Cooking

Cooking

Cooking
JPE Article

JPE Article

Academic
Diving

Diving

Diving
My article on AMAZONAS

My article on AMAZONAS

Aquarium
My aquarium room

My aquarium room

Aquarium
I was featured on a Live TV show

I was featured on a Live TV show

Aquarium

Contact

Get in Touch

Paris/France

refetali@gmail.com

refet.yalcin@saint-gobain.com

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