PROF. E. R. G. ECKERT

H.M.

ht. J. Heat Mass T’ronsfer. Vol. 7, pp. 1147-l 149.

Pergamon Press 1964.

Printed in Great Britain

ERNST R. G. ECKERTON THEOCCASION

OF HISON 13 September 1964, a number of his students
and colleagues, both past and present, gathered
togetherin Minneapolis,
Minnesota,
to payhomage to Professor
Ernst Rudolph
Georg
Eckert on the occasion of his sixtieth birthday.
Many more from around the world, unable to bephysically present in Minnesota, were present inspirit and added their best wishes for manyhappy returns of the day.
Professor Eckert was born in Prague, Czechoslovakia, where he spent his youth. There heattended the German Instituteof Technology,
obtaining
his Diploma
Ingenieur
in 1927 andhis Dr. Ing. in 1931. He remained at the Instituteas an Assistant, engaging in the study of radiation heat transfer in furnaces,
publishinghisearliest papers at this time [Huuptverein dtsch.
Ingen. Mitt. 483486 (1931); Arch. Wkmewirt,
13, 241 (1932)].
In 1935, Ernst Eckert made one of the mostimportantmoves in his life when he moved toDanzig where Ernst Schmidt was Professor andDirector of the Engine Laboratory.
Since Professor Schmidt had been active in research on
thermal radiation,
both from solids and gases,
and Ernst Eckert had developed an interest in
this field at Prague, it was natural that Ernst
Eckert would obtain his habilitationin the fieldof thermal radiation (1938). During this period
at Danzig, under the influence of the outstanding
experimentalist
Schmidt,
Eckert publishedaseries of research papers which are in use to thisday; these covered directional emissivity measurements of metallicand non-metallic
surfaces[Forsch. Geb. Zngen. 6, 175 (1935)], directionalreflectivity values of surfaces exposed to blackbody radiation[Forsch. Geb. Zngen. 7, 265(1936)], an optical projection method of determining radiation exchange factors [Z. Ver. dtsch.
Zng. 79, 1495 (1935)], among many others.
In the late 1930’s he turned his attention fromBIRTHDAY

radiation in solids to radiation from gases andperhaps the results of these efforts represent hismajor contributions
to the radiation
field. He
reportedin 1937 (V.D.Z.-Forsch.
387) theemissivity of carbon dioxide-nitrogenmixturesover a range of partial pressures and gas layer
thicknesses demonstratingthat Beer’s law applies
to carbon dioxide at moderate pressures. With
E. Schmidt, he reported emissivity data for watervapor which explained the discrepancy existingat that time between the earlier results of E.
Schmidt and those of Hottel and Mangelsdorf;
the Schmidt-Eckert
investigation[Forsch. Geb.
Zngen. 8, 87 (1937)] disclosed that Beer’s law is
not valid for water vapor and that the emissivity
is sensitive to the partial pressure of the watervapor. The results of these early radiation
studies of Eckert are publishedin Technische
Strahlungsaustauschrechnungen,V.D.I.-Verlag,
Berlin (1937).
In 1937 Professor Schmidt moved to Braunschweig and shortly thereafterin 1938 Ernst
Eckert followed, taking up a position as docent
at the Institute of Technology and simultaneously
becoming a section chief at the newly established
Aeronautical
Research Establishment(LFA). In
this period Dr. Eckert turned his attention fromthermalradiation
to forced convection
overexternal surfaces and it is the concensus of manyof his colleagues that his greatest contributions
came in this field. In 1940 he and 0. Drewitz(Forsch. Geb. Zngen. 11, 116 (1940)] pointed outthat for constant physical properties the heattransfer coefficient for high speed flows is givenby the same expression as for low speed flows if
it is defined in terms of the difference between
the actual wall temperatureand the adiabaticwall temperature and that this conclusion applies
to turbulent as well as laminar flows. He developed a cylindrical thermometer
to measure theadiabatic wall temperature (Z. Ver. dtsch. Zng. 84,1147
H.M.-3ZSIXTIETH

1148

J. P. HARTNETT

813 (1940)] and withW. Weise presented recovery
factor data for both laminar and turbulent flow
along a cylinder [Borsch. Geb. Ingen. 13, 246(1942)]. Anothermajor
contribution
duringthis period was the developmentof an approximate method for calculatingheat transfer forflow over two dimensional bodies [V. D.I.-Forsch.
416 (1942)]. In recognitionof his contributions
to heat transfer in high velocity flows the dimensionless quantity giving a measure of the temperature increase due to adiabatic compression has
been named the Eckert number.
In 1943 Eckert was offered and accepted aProfessorshipat the Institute of Thermodynamics at his old Alma Mater
the German
Institute of Technology
at Prague, leaving his
academic post at Braunschweig but retaining hisposition at the Aeronautical
Research Institute.
He continued
in these positions until the endof the war in 1945.
On the conclusionof hostilities
Professor
Eckert accepted an offer to come to the UnitedStates and from 1945-49 he was a consultant tothe Power Plant Laboratory at Wright-Patterson
Air Force Base in Dayton, Ohio. Here he wasinvolved in the design and constructionof aZehnder-Machinterferometer
which was usedby him and E. Soehngen for the study of freeconvection
from horizontal
tubes and verticalplates [U.S.A.F. Technical Report 5747, WrightPatterson Air Force Base, Dayton, Ohio (1948)].
In 1949, Dr. Eckert moved to Cleveland as aconsultant
to the compressor
and turbine
division, Lewis Flight Propulsion
Laboratory,
National Advisory Committee for Aeronautics.
In addition to his consulting
commitments
hecontinued
research on free convection
and onmixed free and forced convection.
In 1951 the opportunity
to return to theacademiclife presented
itself when he wasoffered, and accepted, his present position as
Professorof MechanicalEngineering
at theUniversity of Minnesota.
In 1955 he was also
named Director of the Thermodynamics
andHeat Transfer
Division.
During the past 13
years at Minnesota he has continued to do outstanding research over a wide variety of topics
includingconvective
heat transfer
in bothcircular and non-circularpassages, mass transfer
thermalradiation,interferometriccooling,and T.

F. IRVINE,JR.

studies of free convection;
more recently he has
been interested in heat transfer at extremely hightemperatures.
As an indicationof his productivity, Professor Eckert has now authoredorco-authoredover 200 technical papers.
Dr. Eckert’s writings also include five books,
two of them published in German. The English
texts are: Introduction to the Transfer of Heat andMass [McGraw-Hill(1950)], Heat and Mass
Transfer [with R. M. DRAKE, McGraw-Hill(1959)], and his most recent book, Introduction
to Heat and Mass Transfer [translated by J. F.
GROSS, McGraw-Hill(1963)].
Professor
Eckert’scontributions
to heattransfer go beyond his actual published researchpapers. As an outstanding
lecturer and a skilledresearcher he has had inestimableinfluence on
his students and colleagues. Some 20 students
have obtained
the Ph.D. degree under hisguidance
and as a reflectionof Professor
Eckert’s commitment
to education,
18 of these
now hold university
positions. The other two
hold responsible
positionsin the Aerospaceindustry.
In addition
to his teaching
and research
duties at Minnesota,
Professor Eckert has been
active as a technical consultant
to a number ofindustrial
concerns
and governmental
committees. He is also a member of the Advisory
Council of the Mechanical Engineering
Department of Princeton
Universityand a Visiting
Professor at Purdue University.
It may be of special interest to note that heplayed a critical role in the foundingof theinternational Journal ef Heat and Mass Transfer
and has been a co-Chairmanof its Honorary
Editorial Advisory Board since its inception.
In 1961, in recognitionof his many achievements, Professor Eckert was selected to be thefirst recipient of the Max Jakob Medal andAward. The citation that accompanied the award
reads as follows: “For his many and vital contributions
to basic knowledge in heat transfer,
made directly by his experimental and analyticalinvestigations
and also in recognitionof hiscontributions
as an outstanding
teacher whoseenthusiasm
and understanding
has contributed
so widely to the advancementof this importantfield of engineering science.”
To those who have been privileged to know

ERNSTR. G. ECKERT: ON HIS SIXTIETH

and work with Dr. Eckert, he has been an
inspiration not only in technical matters but inpersonal relationships as well. He has been
unselfish with the time he has spent with students
and colleagues, and his quiet good humor andfriendliness without pretension have made such
associations with him richly rewarding experiences.
In addition to his technical and scientificaccomplishments, Professor Eckert finds time
to be a devoted family man. He and his wife,

BIRTHDAY

1149

Josephine Binder Eckert, and their four children,
Christa, Elke, Karin and Dieter, form a charming
group with whom it is always a pleasure toassociate.
We are sure that his many colleagues all over
the world join us in wishing Professor Eckert thehappiest of birthdays and many more years ofsuccessful accomplishments.
J. P. HARTNETT
T. F. IRVINE,JR.