a special tribute to honor stuart churchill on the occasion of his 90th birthday

3
Published: July 27, 2011 r2011 American Chemical Society 8803 dx.doi.org/10.1021/ie200528d | Ind. Eng. Chem. Res. 2011, 50, 88038805 EDITORIAL pubs.acs.org/IECR A Special Tribute to Honor Stuart Churchill on the Occasion of His 90th Birthday Throughout his career, spanning nearly 70 years, chemical engineers have celebrated the advances, writings, oral pre- sentations, and commentary at technical meetings of Professor Stuart W. Churchill, Carl V. S. Patterson Professor Emeritus at the University of Pennsylvania. When editor Donald Paul an- nounced this birthday Festschrift, I was honored, and humbled, by Stuarts request that I write this Preface. The literature is a repository for Stuarts numerous technical papers and books, written in close step with the progression of our profession, many achieved in collaboration with his 45 docto- ral students and colleagues worldwide. Unique, among most of the leading researchers and educators in chemical engineering, are his published talks, editorials, and position papers, often focusing on advances, challenges to be overcome, and future directions for the chemical engineering profession. Stuart has been one of the most active participants in chemical and mechanical engineering conferences, engineering-wide meetings, organizational meetings of AIChE (as President in 1965), and accreditation visits (for ECPD, before ABET), as well as a highly sought after seminar speaker, advisory board member, editorial board member, and consultant. Nearly all of Stuarts writings were collected and scanned for a DVD by his daughter, Emily Sanders, on the occasion of his 85th birthday in 2005. Included were over 400 documents, with a comprehensive Oral History prepared by Joseph Marchese and Jerey Sturchio of the Center for the History of Chemistry in 1985 (currently the Chemical Heritage Foundation). To better appreciate the progression of chemical engineering through the second half of the 20th Century, Stuarts Oral History is an excellent starting point. Special Issue: Churchill Issue Received: March 16, 2011 Accepted: March 16, 2011

Upload: warren-d

Post on 22-Feb-2017

213 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: A Special Tribute to Honor Stuart Churchill on the Occasion of His 90th Birthday

Published: July 27, 2011

r 2011 American Chemical Society 8803 dx.doi.org/10.1021/ie200528d | Ind. Eng. Chem. Res. 2011, 50, 8803–8805

EDITORIAL

pubs.acs.org/IECR

A Special Tribute to Honor Stuart Churchill on the Occasionof His 90th Birthday

Throughout his career, spanning nearly 70 years, chemicalengineers have celebrated the advances, writings, oral pre-sentations, and commentary at technical meetings of ProfessorStuart W. Churchill, Carl V. S. Patterson Professor Emeritus atthe University of Pennsylvania. When editor Donald Paul an-nounced this birthday Festschrift, I was honored, and humbled,by Stuart’s request that I write this Preface.The literature is a repository for Stuart’s numerous technical

papers and books, written in close step with the progression ofour profession, many achieved in collaboration with his 45 docto-ral students and colleagues worldwide. Unique, among most ofthe leading researchers and educators in chemical engineering,are his published talks, editorials, and position papers, oftenfocusing on advances, challenges to be overcome, and futuredirections for the chemical engineering profession. Stuart hasbeen one of the most active participants in chemical andmechanical engineering conferences, engineering-widemeetings,organizational meetings of AIChE (as President in 1965), and

accreditation visits (for ECPD, before ABET), as well as a highlysought after seminar speaker, advisory board member, editorialboard member, and consultant.Nearly all of Stuart’s writings were collected and scanned for a

DVD by his daughter, Emily Sanders, on the occasion of his 85thbirthday in 2005. Included were over 400 documents, with acomprehensive Oral History prepared by Joseph Marchese andJeffrey Sturchio of the Center for the History of Chemistry in1985 (currently the Chemical Heritage Foundation). To betterappreciate the progression of chemical engineering through thesecond half of the 20th Century, Stuart’s Oral History is anexcellent starting point.

Special Issue: Churchill Issue

Received: March 16, 2011Accepted: March 16, 2011

Page 2: A Special Tribute to Honor Stuart Churchill on the Occasion of His 90th Birthday

8804 dx.doi.org/10.1021/ie200528d |Ind. Eng. Chem. Res. 2011, 50, 8803–8805

Industrial & Engineering Chemistry Research EDITORIAL

Unfortunately, in this Preface, I’m unable to focus on even asubset of Stuart’s most significant contributions. Instead, afternearly 50 years with Stuart, 43 at the University of Pennsylvania, Ichose to concentrate on the years following his required “retire-ment” from our standing faculty at age 70 in 1990. During thisperiod, with professionals in their midfifties often encouraged toretire, his achievements were especially impressive. Many retireesremained active in consulting businesses, but unfortunately, theirendeavors were often phased out. The loss of so many experi-enced, active minds, has, in my opinion, often impeded thesolution of challenging problems, the development of new prod-ucts, and overall industrial productivity.Fortunately for our profession, and especially for his close

colleagues, Stuart’s career continues unabated to this day. Hismobility has been reduced somewhat over the past 2�3 years,causing him to spend more time in his study at home, and inparallel, his collection of printed articles was downsized due tospace limitations at Penn. However, personal computers and theInternet arrived just-in-time for him to access the literature fromlocations worldwide. Also, like colleagues everywhere, Stuart putaside written drafts in favor of composing communications(papers, e-mail, ...) using his PC keyboard.

’BRIEF HISTORY

Born and raised in Imlay City, Michigan, with his brothers,James, who became a federal judge in Detroit, and Robert, whopracticed engineering and business, Stuart enrolled in a dual-degree program (to earn Bachelor’s Degrees in Mathematics andChemical Engineering) at the University of Michigan in 1938.After graduation in 1942, he worked at the Shell Oil Companyrefinery in Wood River, IL for 4 years, before joining a colleaguewho started a small engineering venture, Frontier ChemicalCompany in Denver City, Texas, for 1 year. After 5 years inindustry, he entered the chemical engineering doctoral programat Michigan in 1947, received his Ph.D. degree in 1952, became

Assistant Professor in 1952, Associate Professor in 1955, and FullProfessor in 1957, a remarkably rapid rate of promotion. In 1962,he chaired the Department of Chemical and MetallurgicalEngineering, served as AIChE President in 1965, and becamethe Carl V. S. Patterson Professor of Chemical Engineering atPenn in 1967. Until his required retirement in 1990, his focus wason research and teaching, devoid of administrative responsibil-ities. Throughout these years, he received many technical awardsand was elected to the National Academy of Engineering (even-tually receiving its Founders Award). When approached manytimes to consider positions such as Dean of Engineering, hedeclined, preferring to continue his concentration on researchand teaching.Over the past 34 years, Stuart and his wife, Renate (aka Rene�e

Usagi, her nom de plume as a classical guitarist), have lived in theirhome overlooking a small lake in Glen Mills, PA. Beginning in1960, Renate became the associate editor of the journal InternationalChemical Engineering, published by theAIChE. Shewas promoted toeditor in 1974, a position she retained for the next 22 years.In the 1950s, Stuart was at the forefront of the transition of

engineering from a largely empirical discipline to one with astrong orientation toward applied mathematics. Initially, he andhis students made landmark contributions to radiative heattransfer through an atmosphere containing particulates, a keyinput for models of climate change. Later, he developed sophis-ticated scaling concepts at a time when others had not progressedbeyond rudimentary dimensional analysis. With J. David Hel-lums, he developed a generalized system of dedimensionalizationthat leads to the simplest possible description of mathematicalmodels and identifies a similarity transformation, such as those ofBlasius and L�eveque, if one is possible.In the 1960s, 1970s, and 1980s, with many of his students,

Stuart focused on experimental and theoretical research involvingfluid flow and heat transfer, often involving natural convection(based upon research initiated with his student, William R.Martini, in the 1950s), and pioneered in the use of numerical

Figure 1. 90th Birthday dinner at the Gandy-Dancer Restaurant in Ann Arbor, MI on April 23, 2010. Stuart is with 11 of his doctoral students thatattended the birthday dinner (from left to right,Warren Seider,Marty Gluckstein, IrvMiller, JimWilkes, DavidHellums, Stuart,Mark Strenger, HumbertChu, Christina Chan, John Chen, Lance Collins, and Vicki Booker).

Page 3: A Special Tribute to Honor Stuart Churchill on the Occasion of His 90th Birthday

8805 dx.doi.org/10.1021/ie200528d |Ind. Eng. Chem. Res. 2011, 50, 8803–8805

Industrial & Engineering Chemistry Research EDITORIAL

methods to solve the differential models. Gradually, they tackledan array of related problems including migration and freezing ofwater in soil, three-dimensional, unbounded viscous flow be-tween convergent traveling surfaces, thermally stabilized com-bustion in refractory tubes, flow in helical coiled tubes, anddouble-spiral exchangers. With Prof. Hiroyuki Ozoe, a formerstudent, and Paul K.-B. Chao, a doctoral student, he developedthe use of streaklines as a tool for design and interpretation ofcomplex patterns of flow.During these years, Stuart completed a project to unify the

treatment of process calculations in terms of the rate concept,started nearly 2-decades earlier with Robert R. White. The result,which appeared in 1974, was the textbook, The Interpretation andUse of Rate Data: The Rate Concept (McGraw-Hill). This ledRobert L. Kabel to comment in his laudatory paper (Chem. Eng.Commun., 1981, 9, 15): “The Churchill distinction between aprocess rate and a rate-of change clarifies an ambiguous situationreplete with misunderstanding and loose usage.” Another keydevelopment at that time was the Churchill-Usagi equation forinterpolating between two asymptotic or limiting solutions usingjust one empirical constant:

yfxgn ¼ y0fxgn þ y¥fxgn

This expression, because of its generality, minimal empiricism,and remarkable accuracy, is gradually replacing the historicalcorrelations in terms of products of powers of dimensionlessvariables.This diversification of technical areas in transport-oriented

research and teaching reflected the breadth of Stuart’s interestsand his ability to guide research without directing it. In the wordsof his student, Dr. Martin E. Gluckstein, “He gave us enough ropeto create a ladder with a noose and sufficient insight to prevent usfrom hanging ourselves.”

’ LAST TWO DECADES

New topics included thermally stabilized combustion as ameans of devolatilizing coal with Christina Chan and VisitingProfessor Norio Arai, and natural convection in Czochralskicrystallization with Vicki Booker. As his last doctoral studentscompleted their work and he no longer had access to a laboratory,he improvised by working primarily at his desk with a PC, byworking with undergraduates, and by collaborating with colleagues.In the early 1990s, beginning with Christina Chan as an informal

postdoc, Stuart virtually “reinvented” fully developed turbulentflow and convection in channels by expressing the time-averagedequations of conservation in terms of the local fractional contri-bution of the turbulent fluctuations to the shear stress and heatflux density rather than in terms of heuristic quantities such as theeddy diffusivity and the mixing length. One unexpected conse-quence was the discovery that the turbulent Prandtl number canbe expressed wholly in terms of these two fractions and therebythat it has direct physical significance. He utilized the results ofthe contemporary development of direct numerical simulation todevise generalized predictive expressions for these quantities.With his grandson, Stefan Zajic, then an undergraduate at

Penn, he devised theoretically based predictive equations forturbulent convection in channels in the form of analogies that aresubstantially more accurate both functionally and numericallythan the classical ones.The experimental work to supplement his theoretical calcula-

tions as well as some of the calculations were carried out by

collaborators including his colleague, Professor Noam Lior, hisformer doctoral student, Professor Hiroyuki Ozoe in Japan, hisformer visitor, Professor Arai, also in Japan, and Dr. Bo Yu, adoctoral student of Ozoe in China.In the mid-2000s, Stuart increasingly focused on fluid flow and

heat transfer in tubular chemical reactors. In several papers, hedrew attention to the inadequacy of the classical assumption of“plug flow”, that is, perfect radial mixing. The major textbooks onchemical reactor engineering teach students to make this idea-lization in order to simplify tubular reactor models, therebyunwittingly excluding the use of heat transfer to control thetemperature and leading to predictions of reactor length far lessthan those that can be achieved in fully developed flow.This realization led us to add a section to our design textbook

(Seider, Seader, Lewin, and Widagdo, Wiley, 2009), with theassistance of my student, Charles G. Slominski, on the use ofcomputational fluid dynamics to estimate conversions properlyin tubular reactors. We show that secondary flows in spiral tubesincrease conversions, which are increased further using lemnis-cate tubes, approaching the assumption of perfect mixing.At Stuart’s suggestion, we translated this book section into a

research contribution titled “Helical and Lemniscate TubularReactors”, which is coauthored with him in this Festschrift. On thebasis of my doctoral work, in 1971, Stuart and I coauthored a paperentitled “Confined JetMixing in the Entrance of a Tubular Reactor”.Since then, the focus of my research and teaching has been onprocess and product design rather than transport phenomena.Almost 40 years later, our design research comes full-cycle toaccount for fluid mechanics in reactors. Throughout these years,I’ve benefited from Stuart’s engineering science interactions and hiscall for more rigorous transport calculations in obtaining reliabledesigns. Also, after 40 years, it is a privilege to write once again withStuart. As stated by our coauthor, Professor J. D. Seader, “hiswording is as close to poetry as is possible for technical writing.”Viewed differently, Stuart’s breadth extends far beyond that of

most engineering science researchers. His enthusiasm for designresearch and teaching has increasingly suggested interactions forus in recent years. Also, for the last 30 years, even in retirement,Stuart continues to enthusiastically advise one of our seniordesign groups. He understands the importance of teachingstudents how to translate engineering science principles intoprocess and product designs that satisfy consumer needs and toseek designs that optimize profitability in the face of uncertainty.Finally, we were happy to return to Ann Arbor on April 23,

2010 to participate in a joyous celebration of the installation ofProfessor Sharon Glotzer into the Stuart W. Churchill CollegiateChair authorized by the Regents of the University of Michiganand to celebrate Stuart’s 90th Birthday. In Figure 1, Stuart is shownwith 11 of his former doctoral students, fromMichigan and Penn, atthe dinner celebration.

Warren D. Seider

Department of Chemical and Biomolecular Engineering, Universityof Pennsylvania, Philadelphia, PA 19104-6393e-mail: [email protected]