Heat Mass Transfer (2010) 46:1025–1026
DOI 10.1007/s00231-010-0696-1

LAUDATIO

Professor Dr.-Ing. Dr.-Ing. E.h. mult. Karl Stephanon the occasion of his 80th birthday
D. Mewes • A. Luke

Received: 17 September 2010 / Accepted: 17 September 2010 / Published online: 5 October 2010
Ó Springer-Verlag 2010

Professor Karl Stephan will celebrate his 80th birthday onNovember 11, 2010. You are still able to meet him at hisoffice. Asking him about his present activities, he willanswer, that he still does what he always did with muchpleasure and enthusiasm in the past years: heat and masstransfer with phase change in multicomponent mixtures,
thermophysical properties of multicomponent mixtures,
energy transformation processes including their applications
particularly in refrigeration. He will be proud about therecent appearances of the revised editions of the two volume
textbook on ‘‘Thermodynamik—Einstoffsysteme’’, (18thedition in 2009) and ‘‘Thermodynamik—Mehrstoffsysteme
und chemische Reaktionen’’ (14th edition in 1999) as well as
the very well known book, which he wrote together withD. Mewes (&)
Leibniz Universität Hannover, Verfahrenstechnik,Hannover, Germany
e-mail: mewes@imp.uni-hannover.deA. Luke
Institut für Technische Thermodynamik, Universität Kassel,Kassel, Germany

Professor Baehr on ‘‘Wärme- und Stoffübertragung’’ andwhich was published as sixth edition 2 years ago. There isalso the second edition of the English version ‘‘Heat andMass Transfer’’ in 2006. Together with the excellent textbook ‘‘Wärmeübergang beim Kondensieren und Sieden’’(1988), which was translated and published in English
titled ‘‘Heat Transfer in Condensation and Evaporation’’,the books announce to the heat transfer community theoutstanding contributions of a most active, creative andinnovative research and teaching career characterised by thehighest scientific and pedagogical standards.
There are many more manuscripts published by highly
rated international journals, which mark the aim of Professor
Stephan’s research work and which are particularly dated
from the last 15 years, the years of his retirement. It is thecombination of the field of basic engineering sciences inthermodynamics of multicomponent mixtures with that ofheat and mass transfer which provides the engineer withthe understanding and solution of engineering problems
for the energy and raw materials converting industries. Bothbranches of engineering provide the basic knowledge
for most of the processes occurring in energy and processtechnology.
Professor Karl Stephan started his career as an engineer
at the Technische Hochschule Karlsruhe in the stimulating
surrounding of mentors like Plank and Nesselmann. Aftercompletion of his studies in Mechanical Engineering, hereceived his diploma degree in 1956 and became research
assistant to the Institute of Thermodynamics and later on
chief engineer to the Institute of Refrigeration Engineering.
His Dissertation on ‘‘heat transfer and pressure loss in theentrance region of laminar pipe flow’’ marked the first
theoretically based solution which is still valid and frequently cited. He received the degree of Dr.-Ing. in 1959.
Four years later he published his basic results on ‘‘heat123

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transfer in boiling’’ in fulfilment of the requirements of his
habilitation for the lectureship in Thermodynamics.
After his 4-year-lasting career in the industry, he took
the call to the Technical University of Berlin. There hebuilt up a newly founded Institute of Thermodynamics,
which in cooperation with the Institute of Chemical Engineering run by Professor Brauer was the basis for the highstandards of the education at the TU-Berlin in the middle ofthe 1960s. Professor Stephan’s first lectures on thermodynamics of multicomponent mixtures are still in our minds,
because they marked a new start into the field of numericalcalculation of phase equilibria as bases for the design ofseparation processes at that time. This cooperation came toan end with the reorganisation of the faculties at the TUBerlin because of political activities in line with the university reorganisation all over the country at that time. In1970 Professor Stephan went to the University of Bochum
for the next 5 years. Finally in 1975 he succeeded Professor Glaser at the ‘‘Institut für Thermodynamik und
Thermische Verfahrenstechnik’’ at Stuttgart University,where he retired in 1996 from the position of institutedirector. Still active, he is presently guiding his 78th PhDStudent and working on his 273th publication.
Professor Stephan contributed his knowledge to manynational and international committees. Probably the mostoutstanding are the presidency of the Eurotherm Committee, the election to the senate of the Deutsche Forschungsgemeinschaft and to the assembly of mechanicalengineering faculties of German technical universities(Fakultätentag). He received numerous prestigious awards

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Heat Mass Transfer (2010) 46:1025–1026

in recognition of his outstanding scientific reputation. The
most remarkable ones are the Arnold-Eucken-Preis at theage of 35 years and later in 1992 the Arnold-EuckenMedal in commemoration of his lifetime achievements
in education and research. The most prestigious honours
are related to his first assignment in Berlin and demonstratehis esteem and respect in the scientific world. In 1987
Professor Stephan became a member of the Akademie derWissenschaften zu Berlin (West), which was closed after
the reunification of Germany in 1990 and newly foundedin 1993. In the same year Professor Stephan became amember of the new Berlin-Brandenburgische Akademie
der Wissenschaften, which relates back its roots to Leibniz
and the former Academy of Prussia. Two honourable
doctor degrees were awarded to Professor Stephan, in 1993
by the Technische Universität Berlin and in 1994 by theMartin-Luther-Universität Halle-Wittenberg.
This birthday laudation will only mention a few facets
and highlights of Professor Stephan’s life for science andtechnology research. In conversations with him we all
enjoy his clearly voiced and well founded opinions as basis
for decisions in personnel or research related politics aswell as his outstanding creativity as scientist in the fields ofthermodynamics and heat and mass transfer. We honour asympathetic and benevolent supervisor, teacher, doctor
father and, above all, a good friend.
In the name of all authors of this journal we wish
Professor Karl Stephan all the best for his 80th birthday,
many happy returns in good health, many new ideas andmuch pleasure in the surrounding of his family.