Plenary Speakers
Name
Christos N. Markides
Email
c.markides@imperial.ac.uk
Affiliation
Imperial College London
Title
Detailed multiphysics measurements in confined flows with phase-change and reaction
Abstract
Multiphase flows present the experimentalist with a unique set of challenges, such as restricted (often sub-mm) fluid domains with moving and complex interfaces, across which phases have large refractive index changes, leading to optical distortions. Experimental techniques based on optical measurement principles can be applied, but further development is necessary for reliable data to be obtained. Once developed, these techniques can provide information with high spatiotemporal resolution on important scalar (e.g., temperature, concentration, phase) and vector (e.g., velocity) fields in relevant flows, as well as on interfacial characteristics and dynamics.
In this talk, we will present and discuss recent efforts to develop and apply a range of laser-based, infrared and other optical diagnostic techniques to confined two-phase flows with phase change and reaction. We will cover the deployment of simultaneous techniques for the generation of multiphysics and multiscale information, and discuss the specific challenges faced when attempting to perform such measurements. This information is enabling an increasingly complete fundamental understanding of related phenomena, and the improved design of relevant devices, technologies and systems.
Short Bio
Christos Markides is Professor of Clean Energy Technologies, Head of the Clean Energy Processes Laboratory, and leads the Experimental Multiphase Flow Laboratory, which is the largest experimental space of its kind at Imperial College London. He is also, amongst other, Editor-in-Chief of journal Applied Thermal Engineering and founding Editor-in-Chief of new journal AI Thermal Fluids. He specialises in applied thermodynamics, fluid flow and heat/mass transfer processes in high-performance devices, technologies and systems for thermal-energy recovery, utilisation, conversion or storage. He has authored >440 journal and >350 conference articles on topics related to this talk. He has won multiple awards, including IMechE’s ‘Donald J. Groen’ outstanding paper prize in 2016, IChemE’s ‘Global Award for Best Research Project' in 2018, IChemE’s ‘Clean Energy Medal’ in 2025, and received Imperial College’s President Award for Research Excellence in 2017. He has an interest in technology transfer, innovation and commercialisation, most recently as a founding Director of Solar Flow.
Name
David Smeulders
Email
d.m.j.smeulders@tue.nl
Affiliation
Eindhoven University of Technology
Title
Heat storage on reactor scale: theory and experiments
Abstract
Thermochemical materials (TCM) store thermal energy through a reversible chemical reaction in which heat is required to release a previously absorbed sorbate, for example water. The reverse reaction then releases heat. The sorption and desorption takes place in a reactor filled with porous TCM tablets. Through the reactor either hot dry air (for charging the tablets) or cold humid air (for discharging the tablets and heating the air) is pumped. The heat and humidity transfer between the porous material and the air is modeled with conventional convection-diffusion equations. Neutron and CT tomography experiments were carried out to visualize flow patterns and tablet deformations. Considerable volume changes of the tablets occurred during cyclic water hydration and dehydration. The swelling behaviour was subsequently incorporated in the theoretical model. The reactor was also equipped with eight temperature sensors. It was found that the propagating reaction front was well predicted by the model but that there was only limited use for CT measurements to assess the water absorption of the TCM tablets. However, CT measurements were perfectly able to reveal crack formation in the tablets which both affects water absorption and tablet integrity.
Short Bio
Professor David Smeulders holds a MSc from Delft University of Technology in Aerospace engineering and a PhD in Physics from Eindhoven University of Technology. Between 1992 and 2010 he worked at the Civil Engineering and Geosciences Department at Delft University of Technology, where he was also scientific director of the Geotechnology Laboratory. In 2010 he was appointed full professor at the Mechanical Engineering Department at Eindhoven University of Technology, where he currently chairs the Energy Technology group. He is (co)-author of more than 200 scientific publications and member of the Dutch national ‘topsector’ board TKI New Gas, Scientific Director of 4TU.Energy and member of the NWO DeepNL research program committee. He was member of the sounding board to the Dutch parliamentary enquiry of the Groningen gas field.
Name
Jan Taler
Email
jan.taler@pk.edu.pl
Affiliation
Cracow University of Technology
Title
DSc (Habil.), PhD, Eng.
Abstract
In compact plate-fin-tube heat exchangers (PFTHEs), the air-side heat transfer coefficient is often described using exchanger-averaged correlations, even though the flow field varies across the tube rows. This can mask inter-row differences in local convection and reduce the accuracy of 0D/1D performance models. We present a row-wise method for obtaining the air-side heat transfer coefficient and Nusselt number from CFD, using the NTU model with fin efficiency. Three CFD thermal modeling strategies are compared. They differ in the thermal boundary conditions applied to the tube-fin system and in the representation of the fluid-side resistance and the thermal resistance at the tube-fin interface. We evaluate sensitivity to these assumptions, including mesh-independence tests for the most demanding cases. CFD-based row coefficients are evaluated using measurements from a wind tunnel designed for row-by-row identification, with independent measurements of water-side flow and temperature for each row, energy balance corrections for the air-side, and uncertainty estimates provided as confidence intervals. The results identify trends between rows and support the interpretation of increased heat transfer in the last row for selected Reynolds number ranges. Finally, correlations, Nu(Re, Pr), are presented, along with guidance on selecting a CFD extraction method for prediction or use in engineering models.
Short Bio
Jan Taler is a full Professor at the Cracow University of Technology. His main fields of activity are mechanical engineering and thermal power engineering. He is the Head of the Energy Department at the Faculty of Environmental and Energy Engineering. He has held many elected positions, among others, a Member of the Polish Academy of Sciences since 2020, a Member of the Council for Scientific Excellence (Poland) in the cadence 2019-2023, and a Member of the Scientific Council of the International Centre for Heat and Mass Transfer, Ankara/Turkey, since 2018.
His researches in the field of heat transfer engineering and thermal power engineering encompass inverse heat conduction problems, measurement of heat flux and heat transfer coefficient, ash fouling and slagging in steam boilers, boiler dynamics of large steam boilers, numerical modelling of heat exchangers, including superheaters working under steady-state and unsteady conditions, thermal stresses, structural analysis of power plant equipment by the Finite Element Analysis (FEM), monitoring of power boilers, remnant life of pressure elements of boilers working under creep conditions, CFD modelling of heat exchangers, and determination of heat transfer correlations based on the CFD modelling of heat exchangers.
Professor Jan Taler's scientific output includes over 450 publications, 160 indexed in the Web of Science and Scopus databases. He has an Hirsch index of 33, according to the Scopus database. The number of citations of his papers in the Scopus database is 4,200. He is the author or co-author of 12 books, including J. Taler, P. Duda, Solving Direct and Inverse Heat Conduction Problems, Springer, Berlin, 2006; J. Taler et al., Monitoring of Thermal Stresses and Heating Optimization Including Industrial Applications, Nova Science, New York 2016; R. Venkata Rao, J. Taler (Editors), Advanced Engineering Optimization Through Intelligent Techniques, Springer, Berlin 2019, 857 pages and Berlin 2023, 724 pages. A significant scientific achievement of Professor Taler is 11 chapters of about 200 pages in the 11-volume Encyclopedia of Thermal Stresses, Springer, Berlin 2014, edited by Professor Richard Hetnarski.
varianta 2
Plenary Speakers
Name
Christos N. Markides
Email
c.markides@imperial.ac.uk
Affiliation
Imperial College London
Title
Detailed multiphysics measurements in confined flows with phase-change and reaction
Abstract
Multiphase flows present the experimentalist with a unique set of challenges, such as restricted (often sub-mm) fluid domains with moving and complex interfaces, across which phases have large refractive index changes, leading to optical distortions. Experimental techniques based on optical measurement principles can be applied, but further development is necessary for reliable data to be obtained. Once developed, these techniques can provide information with high spatiotemporal resolution on important scalar (e.g., temperature, concentration, phase) and vector (e.g., velocity) fields in relevant flows, as well as on interfacial characteristics and dynamics.
In this talk, we will present and discuss recent efforts to develop and apply a range of laser-based, infrared and other optical diagnostic techniques to confined two-phase flows with phase change and reaction. We will cover the deployment of simultaneous techniques for the generation of multiphysics and multiscale information, and discuss the specific challenges faced when attempting to perform such measurements. This information is enabling an increasingly complete fundamental understanding of related phenomena, and the improved design of relevant devices, technologies and systems.
Short Bio
Christos Markides is Professor of Clean Energy Technologies, Head of the Clean Energy Processes Laboratory, and leads the Experimental Multiphase Flow Laboratory, which is the largest experimental space of its kind at Imperial College London. He is also, amongst other, Editor-in-Chief of journal Applied Thermal Engineering and founding Editor-in-Chief of new journal AI Thermal Fluids. He specialises in applied thermodynamics, fluid flow and heat/mass transfer processes in high-performance devices, technologies and systems for thermal-energy recovery, utilisation, conversion or storage. He has authored >440 journal and >350 conference articles on topics related to this talk. He has won multiple awards, including IMechE’s ‘Donald J. Groen’ outstanding paper prize in 2016, IChemE’s ‘Global Award for Best Research Project' in 2018, IChemE’s ‘Clean Energy Medal’ in 2025, and received Imperial College’s President Award for Research Excellence in 2017. He has an interest in technology transfer, innovation and commercialisation, most recently as a founding Director of Solar Flow.
Name
David Smeulders
Email
d.m.j.smeulders@tue.nl
Affiliation
Eindhoven University of Technology
Title
Heat storage on reactor scale: theory and experiments
Abstract
Thermochemical materials (TCM) store thermal energy through a reversible chemical reaction in which heat is required to release a previously absorbed sorbate, for example water. The reverse reaction then releases heat. The sorption and desorption takes place in a reactor filled with porous TCM tablets. Through the reactor either hot dry air (for charging the tablets) or cold humid air (for discharging the tablets and heating the air) is pumped. The heat and humidity transfer between the porous material and the air is modeled with conventional convection-diffusion equations. Neutron and CT tomography experiments were carried out to visualize flow patterns and tablet deformations. Considerable volume changes of the tablets occurred during cyclic water hydration and dehydration. The swelling behaviour was subsequently incorporated in the theoretical model. The reactor was also equipped with eight temperature sensors. It was found that the propagating reaction front was well predicted by the model but that there was only limited use for CT measurements to assess the water absorption of the TCM tablets. However, CT measurements were perfectly able to reveal crack formation in the tablets which both affects water absorption and tablet integrity.
Short Bio
Professor David Smeulders holds a MSc from Delft University of Technology in Aerospace engineering and a PhD in Physics from Eindhoven University of Technology. Between 1992 and 2010 he worked at the Civil Engineering and Geosciences Department at Delft University of Technology, where he was also scientific director of the Geotechnology Laboratory. In 2010 he was appointed full professor at the Mechanical Engineering Department at Eindhoven University of Technology, where he currently chairs the Energy Technology group. He is (co)-author of more than 200 scientific publications and member of the Dutch national ‘topsector’ board TKI New Gas, Scientific Director of 4TU.Energy and member of the NWO DeepNL research program committee. He was member of the sounding board to the Dutch parliamentary enquiry of the Groningen gas field.
Name
Jan Taler
Email
jan.taler@pk.edu.pl
Affiliation
Cracow University of Technology
Title
DSc (Habil.), PhD, Eng.
Abstract
In compact plate-fin-tube heat exchangers (PFTHEs), the air-side heat transfer coefficient is often described using exchanger-averaged correlations, even though the flow field varies across the tube rows. This can mask inter-row differences in local convection and reduce the accuracy of 0D/1D performance models. We present a row-wise method for obtaining the air-side heat transfer coefficient and Nusselt number from CFD, using the NTU model with fin efficiency. Three CFD thermal modeling strategies are compared. They differ in the thermal boundary conditions applied to the tube-fin system and in the representation of the fluid-side resistance and the thermal resistance at the tube-fin interface. We evaluate sensitivity to these assumptions, including mesh-independence tests for the most demanding cases. CFD-based row coefficients are evaluated using measurements from a wind tunnel designed for row-by-row identification, with independent measurements of water-side flow and temperature for each row, energy balance corrections for the air-side, and uncertainty estimates provided as confidence intervals. The results identify trends between rows and support the interpretation of increased heat transfer in the last row for selected Reynolds number ranges. Finally, correlations, Nu(Re, Pr), are presented, along with guidance on selecting a CFD extraction method for prediction or use in engineering models.
Short Bio
Jan Taler is a full Professor at the Cracow University of Technology. His main fields of activity are mechanical engineering and thermal power engineering. He is the Head of the Energy Department at the Faculty of Environmental and Energy Engineering. He has held many elected positions, among others, a Member of the Polish Academy of Sciences since 2020, a Member of the Council for Scientific Excellence (Poland) in the cadence 2019-2023, and a Member of the Scientific Council of the International Centre for Heat and Mass Transfer, Ankara/Turkey, since 2018.
His researches in the field of heat transfer engineering and thermal power engineering encompass inverse heat conduction problems, measurement of heat flux and heat transfer coefficient, ash fouling and slagging in steam boilers, boiler dynamics of large steam boilers, numerical modelling of heat exchangers, including superheaters working under steady-state and unsteady conditions, thermal stresses, structural analysis of power plant equipment by the Finite Element Analysis (FEM), monitoring of power boilers, remnant life of pressure elements of boilers working under creep conditions, CFD modelling of heat exchangers, and determination of heat transfer correlations based on the CFD modelling of heat exchangers.
Professor Jan Taler's scientific output includes over 450 publications, 160 indexed in the Web of Science and Scopus databases. He has an Hirsch index of 33, according to the Scopus database. The number of citations of his papers in the Scopus database is 4,200. He is the author or co-author of 12 books, including J. Taler, P. Duda, Solving Direct and Inverse Heat Conduction Problems, Springer, Berlin, 2006; J. Taler et al., Monitoring of Thermal Stresses and Heating Optimization Including Industrial Applications, Nova Science, New York 2016; R. Venkata Rao, J. Taler (Editors), Advanced Engineering Optimization Through Intelligent Techniques, Springer, Berlin 2019, 857 pages and Berlin 2023, 724 pages. A significant scientific achievement of Professor Taler is 11 chapters of about 200 pages in the 11-volume Encyclopedia of Thermal Stresses, Springer, Berlin 2014, edited by Professor Richard Hetnarski.
Name
Christos N. Markides
Email
c.markides@imperial.ac.uk
Affiliation
Imperial College London
Title
Detailed multiphysics measurements in confined flows with phase-change and reaction
Abstract
Multiphase flows present the experimentalist with a unique set of challenges, such as restricted (often sub-mm) fluid domains with moving and complex interfaces, across which phases have large refractive index changes, leading to optical distortions. Experimental techniques based on optical measurement principles can be applied, but further development is necessary for reliable data to be obtained. Once developed, these techniques can provide information with high spatiotemporal resolution on important scalar (e.g., temperature, concentration, phase) and vector (e.g., velocity) fields in relevant flows, as well as on interfacial characteristics and dynamics.
In this talk, we will present and discuss recent efforts to develop and apply a range of laser-based, infrared and other optical diagnostic techniques to confined two-phase flows with phase change and reaction. We will cover the deployment of simultaneous techniques for the generation of multiphysics and multiscale information, and discuss the specific challenges faced when attempting to perform such measurements. This information is enabling an increasingly complete fundamental understanding of related phenomena, and the improved design of relevant devices, technologies and systems.
Short Bio
Christos Markides is Professor of Clean Energy Technologies, Head of the Clean Energy Processes Laboratory, and leads the Experimental Multiphase Flow Laboratory, which is the largest experimental space of its kind at Imperial College London. He is also, amongst other, Editor-in-Chief of journal Applied Thermal Engineering and founding Editor-in-Chief of new journal AI Thermal Fluids. He specialises in applied thermodynamics, fluid flow and heat/mass transfer processes in high-performance devices, technologies and systems for thermal-energy recovery, utilisation, conversion or storage. He has authored >440 journal and >350 conference articles on topics related to this talk. He has won multiple awards, including IMechE’s ‘Donald J. Groen’ outstanding paper prize in 2016, IChemE’s ‘Global Award for Best Research Project' in 2018, IChemE’s ‘Clean Energy Medal’ in 2025, and received Imperial College’s President Award for Research Excellence in 2017. He has an interest in technology transfer, innovation and commercialisation, most recently as a founding Director of Solar Flow.
Name
David Smeulders
Email
d.m.j.smeulders@tue.nl
Affiliation
Eindhoven University of Technology
Title
Heat storage on reactor scale: theory and experiments
Abstract
Thermochemical materials (TCM) store thermal energy through a reversible chemical reaction in which heat is required to release a previously absorbed sorbate, for example water. The reverse reaction then releases heat. The sorption and desorption takes place in a reactor filled with porous TCM tablets. Through the reactor either hot dry air (for charging the tablets) or cold humid air (for discharging the tablets and heating the air) is pumped. The heat and humidity transfer between the porous material and the air is modeled with conventional convection-diffusion equations. Neutron and CT tomography experiments were carried out to visualize flow patterns and tablet deformations. Considerable volume changes of the tablets occurred during cyclic water hydration and dehydration. The swelling behaviour was subsequently incorporated in the theoretical model. The reactor was also equipped with eight temperature sensors. It was found that the propagating reaction front was well predicted by the model but that there was only limited use for CT measurements to assess the water absorption of the TCM tablets. However, CT measurements were perfectly able to reveal crack formation in the tablets which both affects water absorption and tablet integrity.
Short Bio
Professor David Smeulders holds a MSc from Delft University of Technology in Aerospace engineering and a PhD in Physics from Eindhoven University of Technology. Between 1992 and 2010 he worked at the Civil Engineering and Geosciences Department at Delft University of Technology, where he was also scientific director of the Geotechnology Laboratory. In 2010 he was appointed full professor at the Mechanical Engineering Department at Eindhoven University of Technology, where he currently chairs the Energy Technology group. He is (co)-author of more than 200 scientific publications and member of the Dutch national ‘topsector’ board TKI New Gas, Scientific Director of 4TU.Energy and member of the NWO DeepNL research program committee. He was member of the sounding board to the Dutch parliamentary enquiry of the Groningen gas field.
Name
Jan Taler
Email
jan.taler@pk.edu.pl
Affiliation
Cracow University of Technology
Title
DSc (Habil.), PhD, Eng.
Abstract
In compact plate-fin-tube heat exchangers (PFTHEs), the air-side heat transfer coefficient is often described using exchanger-averaged correlations, even though the flow field varies across the tube rows. This can mask inter-row differences in local convection and reduce the accuracy of 0D/1D performance models. We present a row-wise method for obtaining the air-side heat transfer coefficient and Nusselt number from CFD, using the NTU model with fin efficiency. Three CFD thermal modeling strategies are compared. They differ in the thermal boundary conditions applied to the tube-fin system and in the representation of the fluid-side resistance and the thermal resistance at the tube-fin interface. We evaluate sensitivity to these assumptions, including mesh-independence tests for the most demanding cases. CFD-based row coefficients are evaluated using measurements from a wind tunnel designed for row-by-row identification, with independent measurements of water-side flow and temperature for each row, energy balance corrections for the air-side, and uncertainty estimates provided as confidence intervals. The results identify trends between rows and support the interpretation of increased heat transfer in the last row for selected Reynolds number ranges. Finally, correlations, Nu(Re, Pr), are presented, along with guidance on selecting a CFD extraction method for prediction or use in engineering models.
Short Bio
Jan Taler is a full Professor at the Cracow University of Technology. His main fields of activity are mechanical engineering and thermal power engineering. He is the Head of the Energy Department at the Faculty of Environmental and Energy Engineering. He has held many elected positions, among others, a Member of the Polish Academy of Sciences since 2020, a Member of the Council for Scientific Excellence (Poland) in the cadence 2019-2023, and a Member of the Scientific Council of the International Centre for Heat and Mass Transfer, Ankara/Turkey, since 2018.
His researches in the field of heat transfer engineering and thermal power engineering encompass inverse heat conduction problems, measurement of heat flux and heat transfer coefficient, ash fouling and slagging in steam boilers, boiler dynamics of large steam boilers, numerical modelling of heat exchangers, including superheaters working under steady-state and unsteady conditions, thermal stresses, structural analysis of power plant equipment by the Finite Element Analysis (FEM), monitoring of power boilers, remnant life of pressure elements of boilers working under creep conditions, CFD modelling of heat exchangers, and determination of heat transfer correlations based on the CFD modelling of heat exchangers.
Professor Jan Taler's scientific output includes over 450 publications, 160 indexed in the Web of Science and Scopus databases. He has an Hirsch index of 33, according to the Scopus database. The number of citations of his papers in the Scopus database is 4,200. He is the author or co-author of 12 books, including J. Taler, P. Duda, Solving Direct and Inverse Heat Conduction Problems, Springer, Berlin, 2006; J. Taler et al., Monitoring of Thermal Stresses and Heating Optimization Including Industrial Applications, Nova Science, New York 2016; R. Venkata Rao, J. Taler (Editors), Advanced Engineering Optimization Through Intelligent Techniques, Springer, Berlin 2019, 857 pages and Berlin 2023, 724 pages. A significant scientific achievement of Professor Taler is 11 chapters of about 200 pages in the 11-volume Encyclopedia of Thermal Stresses, Springer, Berlin 2014, edited by Professor Richard Hetnarski.