Research Group of Working Fluids


Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Energy Engineering



-          Physical-chemical properties of high-pressure fluids (including supercritical states)

-          Selection of working fluids for various energy-related applications

-          Metastable systems and metamaterials


Head of the Group:                                                                                                Researchers:

Prof.  Attila R. Imre, DSc, dr. habil.                                                                        Dr. Axel Groniewsky, PhD, Associate Professor, Deputy Head of the Group

contact:imreattilaat”                                                                       Dr. Gábor Györke, Assistant Professor

                                                                                                                                 Ms. Réka Kustán, PhD student

                                                                                                                                 Mr. Aram Mohammed Ahmed, PhD student


Undergraduate members:

Mr. László Kondor, MSc student, Energy Engineering


Former members

Dávid Velmovszki

Adrienn Katona

Anna Mihók


The Working Fluids group is the member of the COSSMAT network.


Recent publications:

Working Fluids

1.      Attila R. Imre, Sergio E. Quinones-Cisneros, Ulrich K. Deiters: Adiabatic processes in the liquidvapor two-phase region - 1. Pure fluids, Industrial&Engineering Chemistry Research, 53(2014) 13529-13542 ,

2.      Attila R. Imre, Sergio E. Quinones-Cisneros, Ulrich K. Deiters: Adiabatic processes in the vaporliquid two-phase region - 2. Binary mixtures, Industrial&Engineering Chemistry Research, 54 (2015) 6559-6568,

3.      A. Groniewsky, Analysis of Particle Swarm-Aided Power Plant Optimization, Periodica Polytechnica. Engineering. Mechanical Engineering, vol. 59 (3), pp. 102-108, 2015,

4.      Axel Groniewsky, Gábor Györke, Attila R. Imre: Description of wet-to-dry transition in model ORC working fluids, Applied Thermal Engineering, 125 (2017) 963–971,

5.      Gábor Györke, Ulrich K. Deiters, Axel Groniewsky, Imre Lassu, Attila R. Imre: Novel Classification of Pure Working Fluids for Organic Rankine Cycle, Energy, 145 (2018) 288-300,

6.      Axel Groniewsky and Attila R. Imre: Prediction of the ORC working fluid's temperature-entropy saturation boundary using Redlich-Kwong equation of state, Entropy, 20 (2018) 93;

7.      Gábor Györke, Axel Groniewsky, Attila R. Imre: A simple method to find new dry and isentropic working fluids for Organic Rankine Cycle, Energies, 12 (2019) 480,

8.      Attila R. Imre and Axel Groniewsky: Various ways of adiabatic expansion in Organic Rankine Cycle (ORC) and in Trilateral Flash Cycle (TFC), Zeitschrift für Physikalische Chemie, 233 (2019)577-594,

9.      Attila R. Imre, Réka Kustán, Axel Groniewsky: Thermodynamic Selection of the Optimal Working Fluid for Organic Rankine Cycles, Energies, 12(2019)2028;


Supercritical states

10.  A. R. Imre, U.K. Deiters, T. Kraska, I. Tiselj: The pseudocritical regions for supercritical water,  Nuclear Engineering & Design, 252(2012)179-183,

11.  A. R. Imre, C. Ramboz, U.K. Deiters and T. Kraska :Anomalous fluid properties of carbon dioxide in the supercritical regionApplication to geological CO2 storage and related hazards, Environmental Earth Sciences, 73 (2015) 4373–4384,

12.  Imre, A.R., Groniewsky, A., Györke, G., Katona, A. and Velmovszki, D.: Anomalous Properties of Some Fluids - with High Relevance in Energy Engineering - in Their Pseudo-critical (Widom) Region, Periodica Polytechnica Chemical Engineering, 63 (2019)276-285,

13.  Györke, G. and Imre, A.R.: Physical-chemical Background of the Potential Phase Transitions during Loss of Coolant Accidents in the Supercritical Water Loops of Various Generation IV Nuclear Reactor Types, Periodica Polytechnica Chemical Engineering, 63(2019) 333-339,



14.  S. Braun, A. R. Imre, T. Kraska: Stability limits of n-nonane calculated from molecular dynamics interface simulations, Journal of Chemical Physics, 138(2013)244710;

15.  A.R. Imre, A. Baranyai, U. Deiters, P.T. Kiss, T. Kraska and S. E. Quiñones Cisneros: Estimation of the Thermodynamic Limit of Overheating for Bulk Water from Interfacial Properties, International Journal of Thermophysics, 34(2013)2053–2064,

16.  A. R. Imre: Metamaterials with negative compressibility – a novel concept with a long history, Materials Science – Poland, 32(2014)126-129,

17.  I. F. Barna, M. A. Pocsai, A. Guba, and A. R. Imre (2015). Theoretical study of steam condensation induced water hammer phenomena in horizontal pipelines, Kerntechnik, 80 (2015) 420-423,       

18.  Sega, Marcello; Fábián, Balázs; Imre, Attila R.; Jedlovszky, Pal: Relation Between the Liquid Spinodal Pressure and the Lateral Pressure Profile at the Liquid-Vapor Interface, Journal of Physical Chemistry C,  121 (2017) 12214-12219,

19.  Attila R. Imre, Axel Groniewsky, Gábor Györke: Description of the metastable liquid region with quantic and quasi-quintic equation of states, Interfacial Phenomena and Heat Transfer, 5(3) (2017) 173-185, https://10.1615/InterfacPhenomHeatTransfer.2018025457 (real publication year 2018)

20.  Attila R. Imre, Krzysztof W. Wojciechowski, Gábor Györke, Axel Groniewsky and Jakub.  W. Narojczyk: Pressure-volume work for metastable liquid and solid at zero pressure, Entropy 20 (2018) 338;



21.  A. R. Imre: Metamaterials with negative compressibility – a novel concept with a long history, Materials Science – Poland, 32(2014)126-129,

22.  Jakub W. Narojczyk, Krzysztof W. Wojciechowski, Konstantin V. Tretiakov, Jerzy Smardzewski, Fabrizio Scarpa, Pawel M. Piglowski, Mikolaj Kowalik, Attila R. Imre and Mikolaj Bilski: Auxetic Properties of a f.c.c. Crystal of Hard Spheres with an Array of [001]-nanochannels Filled by Hard Spheres of Another Diameter, physica status solidi b, 256 (2019) 1800611,



last update: Dec. 12, 2019 by A.R. Imre (contact:imreattilaat”