Annual progress report 1981

ANNUAL PROGRESS REPORT

1981

1981

FOREWORD

In a sequence of Annual Progress Reports it is useful periodically to review our overall activities rather than describing those events that happened in the year just past. This I shall attempt to do briefly this year.

On the undergraduate level the Institute for Aerospace Studies is committed to provide the education in aerospace engineering in our Faculty, which takes place through the teaching program of the Aerospace option of the Division of Engineering Science. The option curriculum also includes courses that make it a good preparation for students aiming for a research

career in the field of applied physics. The enrolment in this option has

been remarkably steady over the past couple of decades, but has shown a

significant increase this year, with indication of further growth next year.

The graduate enrolment this year is virtually the same as last year's. We have 71 full-time and part-time students which compares with 73 students

last year. Since we have fewer part-time students.now, we have a small

increase in the full-time equivalent count. This confirms the picture of

the last few years of a basically stable enrolment with a modest positive growth rate. Approximately one-third of our students are enrolled in Ph.D. programs. Since the start of operations of the Institute, 131 Ph.D., 379

M.A.Sc. and 24 M.Eng. candidates have successfully completed their degree

programs.

The official exchange program with China regarding the participation of selected Scholars in our research is running at full strength in 1981. We have 8 people in this program at the Institute now and on the basis of our experience we believe that mutual benefits are being achieved.

Our research activities have enjoyed increased financial support. The additional funding from NSERC for its operating grants, a somewhat better success rate with equipment grant proposals and the funding for the develop-ment of new facilities in the shock waves and combustion areas have all contributed to a real level of effort increase in our total research activ-ities. It is unfortunate th at at the same time the support from the University continues its year-to-year decline in real terms.

The following summarizes an up-to-date picture of our current research interests. A new facility is being planned for the study of a variety of effects associated with shock waves moving through dusty gases. The design of the shock tube and construction is now complete and the installation has started. This work is one of the many facets of the research supervised by

Dr. I. I. Glass with the collaboration of Dr. J. Sislian and Dr. J. J. Gottlieb

and which includes oblique shock wave interactions, the study of ionized boundary layers, the potential production of novel materials as well as neutrons through explosive-driven implosions and the field of turbulent com-bustion. This work has enjoyed support from a variety of government research

agencies as well as from industry. Pratt

&

Whitney Aircraft of Canada Ltd.

has assisted with the instrumentation for the combustion research and our

continuing cooperative arrangement with the 3M (Canada) Company provides

mutual benefits in the research on implosion-produced new materials.

As mentioned in last year's report the 3M Group working at the Institute under Dr. N. Salansky has installed new, powerful equipment for basic studies in surface science. The necessary arrangements for the installation of a sophisticated Molecular Beam Epitaxial (MBE) apparatus were completed and the equipment is now in operation. The access, especially of the Fusion

Materials Group, to this unique facility will provide invaluable opportunities for diagnostic work on our surface samples. We anticipate that new opportuni-ties for collaborative research between 3M and other scientists at the University of Toronto will also arise.

The fusion materials work at UTIAS (Professors P. C. Stangeby and A. A. Haasz) has concentrated as a first choice of topic on the erosion due to the impact of hot atomic hydrogen. The space simulator facility was converted for use in this type of research and firm results were obtained with graphite as an example of a likely wall material. The work in this group on the devel-opment of gas target neutron generators is tapering off as the pace of the materials work quickens.

The field of aeroacoustics represents a substantial commitment of effort at the Institute. Professor H. S. Ribner is working post-retirement on a part-time basis in addition to Professors G. W. Johnston, W. G. Richarz and I. I. Glass. They cover a variety of experimental as well as theoretical studies on the sonic boom, jet noise, its shielding and source location, the propagation of noise through ducts and the generation of noise by airfoils. Work on the acoustics of thunder, the annoyance of aircraft noise and the effects of infrasound represent other examples of research interests in this group.

The large air-cushion test track is the most impressive of an array of test facilities available to the air-cushion technology group under Professor P. A. Sullivan. In addition to fundamental work on the dynamics of specific skirt designs, the influence of the skirt material properties on the dynamic instabilities, this group also has done innovative work on the use of air bearings for the transport of bulk goods.

A major new thrust has been made to acquire a significantly improved vehicle simulator facility. With the assistance of Air Canada, which has provided visual display systems and the award of an NSERC strategic grant for a 6-degree motion base, we will be in a position in late 1982 to do our future work on the simulation of aircraft and car in a modern facility which will provide superior visual and motion clues to the pilot/driver. One of the areas of work relates to flight through turbulence, a topic that has been the subject of research by Professors B. Etkin and L. D. Reid. Work on lighter-than-air vehicles, tethered balloons, oscillating airfoils, the analytic design of airfoils, and the testing of scanning LDA methods for wind tunnel measurements represent a selection of subsonic flow projects of interest to Professors J. D. DeLaurier, G. W. Johnston and L. D. Reid. Other applications of fluid dynamics are prominent in the Infrasizer devel-opment by Professor B. Etkin, offering an economic and superior method for particle classification at commercial scale, and Professor A. A. Haasz is supervising an experiment of realistic size as a further step in the devel-opment of the air-curtain as a practical means of protecting large areas from the elements or other hostile environments.

A compact, self-contained instrumentation and recorder package has been developed to make in-flight measurements in small aircraft. It will be used

Continued

(J. H. de Leeuw) in experiments on approach turbulence as well as in new flight laboratory course which is being developed by Professors B. Etkin and

J. H. de Leeuw. The required access to aircraft is provided through a

collab-orative arrangement with the Aviation Program of Seneca College.

Professors R. C. Tennyson and J. S. Hansen cover an area of major impor-tance in structural mechanics and materials science. Their work covers

theoretical as well as experimental work on elastic stability, shell mechanics and fracture mechanics. Finite element methods are extensively studied and

applied in an aircraft crash~worthiness study, in which the analytic predictions

are compared with a few representative experiments.

A substantial effort is devoted to the study of composite materials both for use in aircraft and spacecraft. In particular, the study of the influence of the space environment is performed in four separate space simulators which can expose samples to thermal-cycling, U.V. radiation and electron bombardment and provide in-situ mechanical loading. Eventually samples will be flown on the Long Duration Exposure Facility Space mission for inter-comparison of samples exposed to real space with their counterparts in the laboratory

facil ities • .

Research on the dynamics and control of large spacecraft is one of the specialties in the group supervised by Professor P. C. Hughes. Other work relates to the prediction of orbital life times, modern measurement techniques for the determination of orbit and spacecraft attitude and the dynamics of a class of remote manipulator configurations.

A flourishing research area is the instrumentation field representing the interests of Professor J. B. French. The objective is to delineate improvements in the sensitivity and specificity of mass spectroscopic tech-niques. Projects range from ion lenses for ion mobility focussing to the chemistry of corona discharges. Much of the work is closely related to the potential use of such improvements in the Trace Atmospheric Gas Analyzer instruments. The work is done in close collaboration with Sciex, alocal high technology company.

The use of tunable laser radiation to selectively populate a resonance state and by this means to strongly increase ionization and heating rates is the topic of current interest to Professor R. M. Measures and his research group. The phenomenon is being studied theoretically and an experimental setup to validate the theory and explore potential applications has been built. One attractive possibility that is explicitly studied is the use of the method to create a well defined discharge path to steer charged particle beams onto a fusion target.

In closing, it is a pleasure to note here a few personal items. Professor H. S. Ribner was invited to present the Annual Dryden Lecture of the American Institute of Aeronautics and Astronautics. His lecture, "Perspectives on Jet Noise", was given at the AIAA Aerospace Sciences Meeting at St. Louis in

January, 1981. Professor 1. 1. Glass was elected "University Professor" at

the University of Toronto. This honorary post is held by only twelve people in the University and represents a rare distinction. Our congratulations to both of them. Professor Glass also delivered the first "Paul Vieille Lecture" at the International Shock Tube Symposium at Niagara Falls in July, 1981.

3

J. H. de Leeuw, Di rector.

TABLE OF CONTENTS Personnel Major Installations Institute Laboratories Progress Reports Aeroacoustics

Air Cushion Technology

Flight and Ground Transportation Fusion Energy

Hydrocarbon Fuels

Industrial and Architectural Aerodynamics Laser Resonance Interactions and Applications Mass Spectroscopy and Trace Gas Analysis Shock-Wave Phenomena and Turbulent Combustion Sonic Boom

Space Dynamics and Control

Structural Mechanics and Materials Science Subsonic Aerodynamics

Upper Atmospheric and Flight Research UTIAS Publications 4 Page 5 21 30 37 37 39 41 44 48 49 52 55 57 60 62 64 67 69

STAFF OF THE INSTITUTE FOR AEROSPACE STUDIES

PROFESSOR AND DIRECTOR OF THE INSTITUTE

J. H. de Leeuw, Dipl.Eng. (Delft), M.S. in A.E. (Georgia Tech.), Ph.D., F.R.S.C., F.C.A.S.I., F.A.P.S., P.Eng.

FOUNDER, FORMER DIRECTOR AND PROFESSOR EMERITUS

G. N. Patterson, B.Sc. (Alberta), M.A., Ph.D., L.L.D. (Alberta), D.Sc. (Waterloo), D.Sc. (McGill), F.A.I.A.A., F.C.A.S.I., F.R.A.S., F.R.S.C., F.A.A.A.S.

PROFESSOR AND ASSOCIATE DIRECTOR

J. B. French, M.Sc. (Birmingham), B.A.Sc., Ph.D., F.R.S.C., F.C.A.S.I., F.R.S.A., P.Eng.

UNIVERSITY PROFESSOR

I. I. Glass, B.A.Sc., M.A.Sc., Ph.D., F.A.P.S., F.A.A.A.S., F.C.A.S.I., F.A.I.A.A., F.R.S.C., P.Eng.

PROFESSORS

B. Etkin, D.Eng. (Carleton), B.A.Sc., M.A.Sc., F.R.S.C., F.C.A.S.I., F.A.I.A.A., P.Eng.

P. C. Hughes, B.A.Sc., M.A.Sc., Ph.D., F.C.A.S.I., P.Eng. R. M. Measures, B.Sc., A.R.C.S., D.I.C., Ph.D. (Lond.)

H. S. Ribner, B.S. (Cal. Tech.), M.S., Ph.D. [Wash. (St. Louis)], F.R.S.C., F.C.A.S.I., F.A.I.A.A., F.A.P.S., F.A.S.A. R. C. Tennyson, B.A.Sc., M.A.Sc., Ph.D., F.C.A.S.I., P.Eng.

ASSOCIATE PROFESSORS

J. D. DeLaurier, B.S. (Illin.), M.S., Ph.D. (Stan.) J. S. Hansen, B.A.Sc., M.A.Sc., Ph.D. (Waterloo), P.Eng. G. W. Johnston, B.A.Sc., M.A.Sc., Ph.D., F.C.A.S.I., P.Eng. L. D. Reid, B.A.Sc., M.A.Sc., Ph.D., P.Eng.

P. C. Stangeby, B.Sc., M.Sc., Dipl.-Sci., D.Phil. (Oxon)

P. A. Sullivan, B.E., M.E. (N.S.W.), D.I.C., Ph.D. (Lond.), F.C.A.S.I., P.Eng.

ASSISTANT PROFESSORS

A. A. Haasz, B.A.Sc., M.A.Sc., Ph.D., P.Eng. W. G. Richarz, B.A.Sc., M.A.Sc., Ph.D.

NSERC UNIVERSITY RESEARCH FELLOW

J. J. Gottlieb, B.Sc., M.Sc. (Sask.), Ph.D., P.Eng.

VLSITING AND ADJUNCT PROFESSORS

F. Cicci, B.A.Sc., M.A.Sc., Ph.D., Adjunct Assistant Professor

J. E. Robinson, B.Sc., M.Sc. (Manitoba), Ph.D. (MIT), Adjunct Professor N. Salansky, Ph.D. (Krasnoyarsk), D.Sc. (Novosibirsk), Adjunct Professor H. Sugiyama, B.Eng. (Kanazawa), M.Eng., Dr.Eng. (Tohoku), Visiting Professor

VISITING RESEARCHERS

X. X. Ou, Beijing Aeronautical Institute Z. Hu, Nanjing Aeronautical Institute

J. H. Lee, B.Eng., M.Eng. (Waseda), Dr.Engng. (Tokyo) Y. H. Lin, University of Fudan, Shanghai

G. X. Liu, Aeronautical Scientific

&

Technical Institute, Xiangfan

Z. Y. Lu, Beijing Aeronautical Institute H. Miura, B.Eng., M.Eng., Dr.Engng. (Kyoto)

R. Qi, Harbin Shipbuilding Institute, Heilongjiang D. Sagie, B.Sc. (Technion)

V. G. Sheng, Nanking Aeronautical Institute M. Shirouzu, B.Eng., M.Eng. (Kyushu)

R. S. Srivastava, M.Sc., Ph.D. (Lucknow), F.N.A.Sc.

M. Temizkaya, B.Sc. (Istanbul), Ph.D. (Strathclyde), Istanbul Technical University

S. Zhu, Beijing Aeronautical !nstitute

RESEARCH ASSOCIATES

O. H. Auciello, B.Sc., M.Sc., Ph.D. (Cuyo)

M. J. Hinchey, Dipl.Eng. (Memorial ), B.A.Sc., M.A.Sc., Ph.D.

J. P. Sislian, M.Sc. (Verevan), Cand. Phys. & Math. Sci. (Moscow), Ph.D. R. Underhill, B.Sc. (Trent), Ph.D. (Vork, U.K.)

RESEARCH STAFF

S. Basu, B.Sc., Ph.D. (Lond.) W. E. R. Davies, B.Sc. (Ottawa)

W. O. Graf, B.Sc., M.Sc. (Eng.) (Pretoria) T. A. Graham, B.Sc. (Queenls), M.A.Sc. G. R. Heppler, B.A.Sc., M.A.Sc.

G. E. Mabson, B.A.Sc., M.A.Sc.

M. T. Thomas, M.Sc. (Memorial}, Ph.D. B. T. Uffen, B.A.Sc., M.A.Sc.

SPECIAL LECTURERS

S. F. Archer, B.A.Sc., M.A.Sc. H. R. Bishop, B.Eng. (N.S.)

B. Eggleston, Aero.Eng. (Bristol), M.Sc. (Cranfield) G. Georges, B.A.Sc.

D. M. Gossain, B.Tech., M.Eng. (IIT, Kharagpur), M.Eng. (McMaster) R. A. Harvey, B.Sc. (Imperial Coll.)

A. S. Jones, B.A., M.A. (Engng.) (Cambridge) L. Keyes, B.Sc. (Queenls)

G. B. Lang, B.Sc. (Adelaide) P. S. M:lrtin, P.Eng., F.R.Ae.S. G. Oates, B.Eng. (Manchester)

D. C. Oswald, Dipl.Aeron.Engng., M.Sc. (Cranfield) P. A. Thompson, B.A.Sc.

CONSULTANTS

W. Czerwinski, Dipl.-Ing. (Lvov), F.C(A.S.1.'lPTE~9. )

W. S. L iu, B.Sc. (Cheng Kung), M.Sc. Nationa alwan, Ph.D. (Toronto),

P.Eng.

S. Reinis, M.D., Ph.D. (Charles)

LIBRARIAN

Mrs. Asta Luik, B.A. (Estonia) , B.L.S., M.L.S. (Toronto)

RESEARCH ASSISTANTS S. Ando A. B. Antoniazzi J. R. Arkema C. D. Basham S. H. F. Behman D. Bergeron J. C. Bi rd A. J. M. Bressers K. L. Buhariwa 1 a B. Bu1ut J. E. Byrne M. A. Cappe11 i P. G. G. Cardina1 S. G. Cavalcanti P. W. Chodas Z. H. Chowdhury J. D. Col es M. A. Daoud T. E. Darcie J. R. J. deLafontaine G. M. T. D'E1euterio E. De11a Pen na J. A. Del Mora 1 R. L. Deschambau1t B. C. Eatock W. G. Elliott J. R. Evans R. G. Fehr I. G. Fejtek R. G. Foster P. A. Gagnon M. J. Giliberto D. Go" a D. R. Greatrix G. M. Green H. Herchen J. C. C. Ho J. T. C. Hu K. C. K. Hui J. R. B. Johnston B. G. Kamen J. G. Kavanagh S. E. Keith R. S. Ki ssack J. Kleiman V. Kotasek W. L. Kung D. K. W. Lam A. Lanouette B. A. Lay R. LeB1anc Z-q. Liu R. B. MacKenzie A. Manz A. B. Markov D. A. McCoy W. D. McKinney N. J. McNe i 11 W. D. Morison S. Y. Nacson M. Nahon A. P. Nanyaro D. J. Nob 1 e

ADMINISTRATIVE AND TECHNICAL STAFF

C. Basdeo S. Hitchman K. Bopp H. Kleinberg J. L. Bradbury J. Leffers P. Cooke J. H. tkCormack W. Di 11 on J. Mi11s D. Doug1as E. Moffitt R. Eisen A. Morte M. Fitzgera1d C. Perez 7 P. Ostaff J. G. Parravano W. H. Pinchin J. Potjewyd M. E. Rababy D. V. Ritze1 H. S. 1. Sadek T. Sa ito G. W. Schinn H. S. B. Scho1aert P. Sergejewich R. Shafro F. N. Shen M. Simard G. B. Sincarsin W. G. Sincarsin B. A. W. Smith J. Smith E. N. So 1 owka P. S. Spedaler I. A. Stoddard A. T. Vour1as N. N. Wahba C. Wa1sh G. S. WEst-Vukovich F. C. Wong R. L. M. Wong S. S. K. Wong L. K. Wood J. A. Zapfe D. W. Zingg A. Perrin L. Quintero W. Ryan H. Schumacher J. Tonigold J. Unger D. R. Wilrnut

Left to right: Dr. G. N. Patterson, Miss Susan BiZZington, Mrs. MiZdred BiZZington, Mr. James BiZZington, Mr. PauZ G. CardinaZ, Dr. J. H. de Leeuw.

Each year the Institute honours an alumnus by inviting him to return and

re1ate his career experiences in the Gordon N. Patterson Lecture. Dr.

Ian J. Bi11ington was to be the G. N. Patterson Lecturer.

Dr. Bi11ington comp1eted his Ph.D. at the Institute for Aerospace Studies in 1955 where he subsequent1y held appointments for a number of years as Research Associate and Special Lecturer. In 1957 he joined Dilworth, Secord, Meagher and Associates, becoming Vice President and a Director of

DSMA ~tcon Ltd. in 1977. Throughout his career he made many contributions

ranging from the design and construction of wind tunnels, component design of the RMS Arm of the space shuttle, and heavy oi1 pumping, to name a few. Dr. Bi11ington passed away on August 9,1981.

The plaque, commemorating the 1981 G. N. Patterson Lecturer, was presented to Mrs. Bi11ington by Professor Patterson. In addition, the recipient of the G. N. Patterson Award was introduced. Pau1 G. Cardina1 was se1ected for his contributions to theoretica1 and experimenta1 aspects of laser interactions based on resonance saturation (LIBORS).

Photo: Steve BehaZ

Professor lrvine Glass (right), along with Professors Hans Eichner (left) and Robert Salter (centre), was named University Professor, the highest honour that the University of Toronto confers on a faculty member.

Each year, nominations are considered by a presidential advisory committee whose criteria are excellence in teaching and research, but the honour is not necessarily bestowed annually. The first to receive the award was Northrop Frye.

No more than 15 University Professorships may exist at any one time. At present there are 12. The title is customarily held until age 65, when it becomes University Professor Emeritus.

On January 12, 1981, at the 19th Aerospace Sciences meeting of the American Institute of Aeronautics and Astronautics (AIAA), Professor Herbert S. Ribner presented the annual Dryden lecture entitled, "Perspectives on Jet Noise". The Dryden lectureship in research "is intended to emphasize the great importance of basic research to programs in aeronautics and astronautics and to be a salute to research scientists and engineers, and named in honour of Dr. Hugh L. Dryden, renowned leader in aerospace programs".

The award consists of a medal, certificate of citation, and a rosette pin; these were presented to Professor Ribner by AIAA president, A. Mager. This is not the first time that the AIAA has honoured Professor Ribner; in 1976 he received the prestigious Aeroacoustics award. Having been active over a wide spectrum of physics and" engineering research, Professor Ribner has most recently become intrigued by the acoustics of thunder, and the staff and students of the Institute wish him all the best in this and future endeavours.

Professor I. 1. Glass delivered the premier "Paul Vieille Lecture" at the 13th International Symposium on Shock Tubes and Waves. He is shown with Dr. J. Gordon Hall, Chairman, while answering some questions at Niagara Falls, New Vork, July 6, 1981.

Dr. J. B. French obtained his B.A.Sc. in Chemical Engineering, University of Toronto, t4.A.Sc. in Thermodynamics at

Birmingham, England, and Ph.D. in Plas-madynamics at UTIAS, where he joined the staff in 1961. His general fields of interest include gas dynamic mole-cular beams, space simulation, trace gas analysis instrumentation development, and many applications of the latter in environmental, military, medical and other areas. His projects included ion

source development with Prof. A. O. Nier

of Minnesota for the highly successful Project Viking t4artian upper atmospheric mass spectrometer. His research has led to major advances in atmospheric pressure chemical ionization mass spectroscopy. Patents which make APCI/MS practical as a research and analytic tool (held

jointly with N. M. Reid, J. A. Buckley)

have been developed in Canada into a commercial instrument. Recently, Dr. French has been appointed to hold a

watching Brief for ~RC on Satellite

Solar PO\'/er systems. He is a Fellow of the Canadian Aeronautics and Space

Institute, a Fellow of the Royal Society of Arts, and a member of the AIAA and the AlP.

12

Professor J. H. de Leeuw obtained his

Engineering Diploma in Aeronautical Engineering at the Delft Technical University in Holland. He obtained his M.S. degree in Aeronautical Engineering at the Georgia Institute of Technology and his Ph.D. in Aerophysics at the Institute for Aerospace Studies of the University of Toronto. He joined the staff of UTIAS in 1958 and is now

Director of the Institute. His original interest in shock tubes and their use in MHD research shifted subsequently to largely experimental work in low density gas and plasma flows with a special em-phasis on the development of new measuring techniques. Adaptations of these labora-tory techniques led to the construction of special rocket instruments for the measure-ment of the properties of the upper atmos-phere. More recently his interests have included flow problems associated with fusion technology. Professor de Leeuw is a member of the NRC Advisory Committee on Fusion Research, he is a Fellow of the Canadian Aeronautics and Space Institute and a Fellow of the American Physical Society.

Dr. B. Etkin obtained his B.A.Sc. degree in Engineering Physics at the University of Toronto and an M.A.Sc. in Aeronautical Engineering. He has been on the staff of the Engineering Faculty since 1942. He served as Chairman of the Division of Engineering Science from 1967-1972 and as Dean of the Faculty from 1973-1979.

Professor I. I. Glass obtained his Bachelor and Master degrees (Engineering Physics-Aeronautical Engineering) and Doctorate (Aerophysics) at the University of Toronto in 1950, wh en he joined UTIAS. His fields of study have centred on gas-dynamics and shock-wave phenomena. He is currently interested in various types of nonstationary oblique-shock-wave reflec-tions in perfect, imperfect and dusty gases; implosion dynamics with a view to fusion diagnostics and new materials; effects of sonic boom on structures and shock-wave transitions in N-waves; turbulent combus-tion; corner-expansion-wave interaction with flat-plate boundary layers in ionizing argon flows. Professor Glass is a Fellow of the Royal Society of Canada, the American Physical Society, the American Institute of Aeronautics and Astronautics, the American Association for the Advancement of Science and the Canadian Aeronautics and Space Institute. He received the highest honour the University of Toronto can bestow on one of its faculty members, by being named a distinguished "University Professor" in Octob:r. 1981.

His research interests have included air-craft structures, wing theory, shock waves, stability and control of aircraft, satel-lites and re-entry vehicles and aerosonics. His two books on "Dynamics of Flight" have been widely used in English, Russian and German editions. He has served for many years as a consultant to U.S. and Canadian

industry and government and spent consider-able time in the aircraft industry during and af ter World War 11. His current research interests include the effects of atmospheric turbulence on flight vehicles, lighter-than-air lighter-than-aircraft, applications of lighter-than-air curtains, and aerodynamic means of sorting fine par-ticles. He is a Fellow of the Royal Society of Canada, of the CASI, and of the AlAA. He received the McCurdy Award in 1969, an hon-orary D.Eng. fr om Carleton University in 1971, and the Mechanics and Control of Flight Award of the AIAA in 1975.

Professor R. M. Measures obtained his Bachelor and Doctorate degrees in Honours Physics at Imperial College of Science and Technology, London University, England. He has worked in the area of applied physics since he joined the staff of the Institute in 1964. His early work involved the mea-surement of atomic collision cross sections by laser interferometric studies of shock waves and the development of a new approach at local plisma diagnostics using laser selective excitation spectroscopy. Dr. Measures spent a sabbatical year (1972-3) at the "Royal Institution of Great Britain" where he studied the possibility of develop-ing a laser based on Electrochemiluminescence. Over the past decade, he has maintained a substantial interest in laser environmental sensipg, developing Canada's first laser fluorosensor and contributing a comprehen-sive chapter on the subject for a text on Laser Spectroscopy. His current interests include the development of a new kind of Laser Trace Element Microprobe and a study of laser created plasma channels that could be of importance in particle beam fusion.

14

Professor P. C. Hughes obtained his Ph.D. from the University of Toronto (1966) in Aerospace Engineering Science. Most of his research has been related to space vehicle dynamics and control, including significant contributions to the dynamical rnodel-ling of the AlouettejISIS and Hermes satellites and of the NASA Space Shuttle manipulator arm. Current interests include the application of modern con trol theory to this class of applications, and the dynamics and control of large space structures. Professor Hughes is a Fellow of the Canadian Aeronautics and Space Institute, and reviews regularly for the U.S. aerospace journals.

Prof. R. C. Tennyson obtained his B.A.Sc. at the University of Toronto and his graduate degrees (M.A.Sc., Ph.D.) at the Institute for Aerospace Studies. Af ter joining the Institute staff in 1965, he continued to work in the Structural Mechanics area with special interest in shell buckling problems. During these intervening years, his interests have expanded to

include stress waves in solids, com-posite materials, biomechanics and

Dr. H. S. Ribner obtained his B.S. from Caltech and his M.S. and Ph.D. (1939) from Washington University (St. Louis), all in physics. Af ter a short period in gravity meter development, he spent eight years at the NACA (predecessor of NASA) Langley Laboratory and five years at the Lewis Laboratory, variously as aerodynamicist and section head (Stability Analysis Section, Langley, Boundary Layer Sections, Lewis). He joined the Institute staff in 1955, was a Visiting Professor at Univer-sity of Southampton in 1960-61, and a Staff Scientist at NASA Langley in 1975-76. His research interests have covered, some-what chronologically, X-rays, cosmie rays, gravimetry, aerodynamics, aeroacoustics, sonic boom, and the acoustics of thunder. Professor Ribner is a Fellow of the Royal Society of Canada, the Canadian Aeronautics and Space Institute (CASI), AIAA and other American societies. He was the CASI Turn-bull Lecturer in 1968, Chairman of the ICAO Sonic Boom Panel in 1970-71, and received the AIAA Aeroacoustics Award in 1976. Currently he divides his time between UTIAS and NASA Langley.

space simulation studies. Dr. Tennyson is a member of the National Research Council of Canada Associate Committee on Aerospace Structures and Materials, the American Institute of Aeronautics and Astronautics and a Fellow of the Canadian Aeronautics and Space Institute.

Dr. Hansen obtained his B.A.Sc.,

M:A:S~. and Ph.D. degrees in the

Dlvlslon of Solid Mechanics of the Department of Civil Engineering at the University of Waterloo. He then worked at the Technical University of Denmark and at University College London, Engl~n~ as a NATO Postdoctorate

~ellow. He JOlned the Institute staff

ln 1975 and is at present an Associate Professor. Dr. Hansen's current re-search.empha~is is primarily in solid mechanlcs WhlCh includes programs in the theory ?f elastic stability, frac-ture mechanlcs, crashworthiness of air-craft str~ctures, influence of the

space env~r?nment on mmposite materials and the fl nl te element method.

16

Dr. DeLaurier obtained his Bachelor degree fro~ the University of Illinois, af ter which he worked as an aerodynam-icist at McDonnell Aircraft. Subse-quently, he went to Stanford University where he received a Master and Ph.D. degree (1970). Af ter a year at the von Karman Institute for Fluid Dynamics, Dr. DeLaurier returned to industry, first, as a balloon analyst at Sheldahl Inc., and next, as a research engineer at Battelle Memorial Institute. Upon joining the staff at UTIAS in late 1974, Dr. DeLaurier has continued his work on Lighter-than-Air Technology, where he has developed programs for predicting the stability and control of modern airships, and their response to atmos-pheric turbulence. Other research interests include unsteady subsonic aerodynamics and subsonic separated flows involving bound vortices. Dr. DeLaurier is a member of the Interna-tional Astronautical Federation's subcommittee of Lighter-than-Air Technology, and is areviewer for Applied Mechanics Reviews.

Professor

G.

W. Johnston received his Ph.D. from the University of Toronto, Institute of Aerophysics (1953). He spent 10 years with the de Havilland Aircraft Co. of Canada being responsible for a number of advanced STOL research and development projects. He joined the Research Laboratories of the United Tech-nologies Corp., East Hartford, Connectieut, in 1967 as Aerodynamic Consultant to their Fluid Dynamics Department. Activities here included the creation and development of a basic aeroacoustics research group and development of the anechoic wind tunnel facility. He joined the Institute staff in 1970 specializing in aeroacoustic research. Current research interests include the development and propagation of sound by aerodynamic bodies. Subjective "annoyance" research is also of continuing interest. Dr. Johnston is a Fellow of the Canadian Aeronautics and Space Institute.

Dr. L. D. Reid earned his B.A.Sc., M.A.Sc. and Ph.D. degrees in Aerospace Engineering at the University of Toronto. He first joined the staff of the Institute as a Special Lecturer in 1965 and is presently an Associate Professor. His research

interests lie in the general areas of flight and ground vehicle simulation and aircraft stability and control. At the present time Dr. Reid is investigating the response of aircraft to wind shear and low altitude turbulence during the landing approach. Other current research studies include the development of an advanced general purpose simulator facility and an investigation into the performance of automobile and truck drivers. Dr. Reid is an Associate Fellow of the Canadian Aeronautics and Space Institute and of the American Institute of Aeronautics and Astronautics. He is a registered pro-fessional engineer and acts as a consultant to industry and government agencies.

Dr. P. A. Sullivan obtained his Bachelor's and Master's degrees in

r~echanical Engineering at the

Univer-sity of flew South ~Jales, Australia, and then travelled to England to work for his Doctorate in Aeronautics at the Imperial College of Science and Technology, London. Af ter a post-doctoral year at Princeton Uni versity , he j oi ned UTIAS in the fa 11 of 1965, where he pursued his research interests

in hypersonic aerodynamics and boundary layers. In response to declining in-terest in this area in Canada in the early 1970's, and to renewed Canadian interest in air cushion vehicles, he developed a research program in the latter area. With the aid of generous funding from the National Research Council of Canada and the Transporta-tion Development Agency this program is now well established. Dr. Sullivan is a Fellow of the Canadian Aeronautics

Dr. P. C. Stangeby obtained his Bach-elor and Master degrees in Mathematics and Physics at the University of Toronto, and his Doctorate in Engineering Science (Plasmas) at Oxford University, joining the Institute staff in 1972. His primary research interest is in fusion energy. Current emphasis is on plasma-surface interaction studies re1ated to wal1 mate-ria1s development for fusion reactor con-ditions. Research on the Gas Target Neutron Generator concept is directed toward the deve10pment of an intense neutron source for fusion materials studies. Other energy research interests include synthetic fue1 production fr om oi1 sand, coal and biomass feed-stocks. Dr. Stangeby is a member.of the AIAA, the Canadian Association of

Physicists and the (UK) Institute of Physics.

and Space Institute, and of the American Institute for Aeronautics and Astronautics. He is a 1icensed professional engineer and has active consultancies in air cushion technology.

Dr. Richarz joined UTIAS in 1978 af ter completing his studies in aerospace engineering at the University of Toronto. Much of his theoretical and experimental research has been directed at sound gen-eration by unsteady flows. The scope ranges from noise of turbulent ~lames (:om-bustion noise) to sound productlon by alr jets. Over the years Dr. Richarz has

devised a number of instruments and measure-ment techniques for acoustical and fluid flow research. Present emphasis centres on fundamental and applied research into tur-bulent flows and their sound generating mechanisms. In addition Dr. Richarz has

interest in suppression of interior noise of aircraft, unsteady aerodynamics and signal processing. Dr. Richarz is a member of AIAA, CASI, and an associate member of the Acoustical Society of America.

19

Dr. A. A. Haasz obtained his B.A.Sc., M.A.Sc. and Ph.D. degrees in Aerospace Science and Engineering at the University of Toronto. His graduate research involved electron impact excitation cross-section measurements with rocketborne electron be am fluorescence probes. Af ter joining the Institute staff in 1972, his research interests expanded to include thermonuclear fusion technology, with a focus on fusion reactor materials. Earlier work in this area involved gas and plasmadynamic studies of the gas target neutron source concept, proposed for the production of 14 MeV neu-trons. Current research effort is concen-trated on plasma-surface-interactions, in particular, the interaction of atomie hydro-gen, electrons and ions with candidate materials for current and future generation Tokamaks. Dr. Haasz is aregistered

professional engineer and is a member of CAP, CASI, APS, AVS and AIAA.

N

-+::>

LOW DENSITY WIND TUNNEL

The Institutels Low Density Hind Tunnel, LDHT, was constructed for studies of rarefied gasdynamics and to

simulate the near space environment. The LDWT consists of nine vacuum booster pumps capable of 18,000 l/S

pumping speed at 10-2 _{torr, backed by Roots Blowers and mechanical pumps. Currently, the LDWT is finding}

application outside the traditional aerospace field, in fusion energy studies on a gas target neutron generator concept. Such studies are only possible with large gas pumping facilities, such as the LDWT, which are generally unique to aerospace laboratories.

N U1

PLASMA TUNNEL

The Plasma Tunnel is a low density flow facility which can be operated in different pumping modes. It can be operated at background flow pressures up to about 10 Pascal (1 Pascal = 1.3 micron of Hg) at volume flow rates of several 1000 liter/sec. Alternatively, it can provide working pressures near its blank-off pressure of about 5 x 10-3p at effective flow rates of 500 ~/sec. Plasma flows can be produced by an RF arc source operating near atmospheric pressure and te~peratures of 5000K or by an ion thruster providing high speed-ratio plasma flows for low mass flow applications. The test section, with a diameter of 2m and a volume of 15m3, is equipped with a traversing mechanism, extensive pressure instrumentation, and an electron beam fluorescence probe. It is a con-venient test chamber for a variety of tests at intermediate vacuum levels.

N

0"1

TRAVELLING - WAVE

SONIC-BOOM SIMULATOR

This facility consists essentially of a large-volume compressed-air reservoir (two tanks outside and one

inside), an air compressor, a special electromechanically operated flap valve at the horn apex, a concrete pyra-midal horn (25m long, 3m by 3m base), porous-piston

reflection eliminator covering the base, and a psycho-acoustic or structural test room linked to the horn interior by a cutout. Sonic booms from supersonic transport and military aircraft (Concorde, F-18) can be simulated to facilitate investigations of human, animal and structural response. Recent research includes studies of: room resonance to a sonic boom entering by

an open window (one room only, two rooms interconnected by a window), plaster-wood wall response to sonic-boom

induced room pressures, and crack propagation in plaster walls subjected to a sonic-boom loading.

N '-J

SPACE SIMULATION AND MOLECULAR BEAMS FACILITY

The facilities consist of a high speed gasdynamic molecular beam system, with recently developed intense

mono-energetic atomic hydrogen and atomic oxygen sources for simulating upper planetary orbital flight, for basic studies of reactive gas-surface interactions, for development of spacecraft instrumentation or for simulation

of atmospheric surface effects in orbit on advanced engineering materials, such as composites, etc. A 9 ft

diameter ultra clean, ultra high vacuum thermal vacuum space simulation chamber is available, and molecular beams of up to several centimeters in diameter can be introduced. Several smaller chambers are available for specialized studies, and include a variety of mass spectrometer, vacuum, surface deposition and other instru-mentation. Recently the Space Simulator has been used for plasma-surface interaction studies of interest in fusion energy development.

General view of wind tunnel.

SUBSONIC

The subsonic wind tunnel was originally designed to perform aerodynamic tests on aircraft and aircraft components in a low turbulence test section. As our research emphasis shifted towards an interest in the influence of turbulence on aerodynamic performance a decision was made to recon-figure the test section into one more suited to such work. A recently completed program has converted the facility into a boundary layer wind tunnel capable of a wide range of turbulent flow simulations. The tunnel has a closed circuit and is

powered by both a fan in the return duct and by a unique jet grid fed from an external blower. Control over the flow from this jet grid is used to tailor the velocity profile in the l.lm x 1 .7m test section.

The wind tunnel 1 aborato'ry instrumenta-tion includes 4 channels of DISA hot wire anemometry, a TR-48 analog compu~er and a

HP 2l00A digital computer. This equipment is used to set up the flow conditions in the tunnel and to take measurements and analyze data. Sharing the computers is a general purpose manned simulation facility used for a variety of man/machine system evaluations.

WIND TUNNEL

General purpose manned simulation facility. Analog and digital computers. 28

N \.0

VACUUM SPHERE AND HOT FLOW TEST FACILITY

The vacuum sphere, of volume 1000 m3 , can be pumped down to less than 10-3 atm pressure, and used as a high

mass-flow, blow-down test facility, e.g., as a hypersonic wind tunnel. The vacuum pumping plant, insert,

can also operate in a compression mode and in conjunction with an electric gas heater can perform as a hot

INSTITUTE LABORATORIES

Anechoic room with model jet. Anechoic wind tunnel.

AEROACOUSTICS LABORATORY

Aeroacoustics is the study of sound associated with airflow; it is an intriguing

combination of aerodynamics and acoustics. UTIAS researches spread over a quarter century - both experimental and theoretical - have included aeolian tones, the noise from boundary layers, jets, turbulence and combustion, as well as sonic booms and even thunder. The Aeroacoustics Laboratory centres around the two

anechoic chambers pictured above. Both can accommodate model air jets, and the

right hand one may be traversed by a 3 foot open jet capable of speeds up to

70 mjsec. In addition there is a duct flow facility with comparable flow speeds.

Measurement of jet flow is via hot wire anemometry and a laser Doppler velocimeter

(LDV). Acoustic instrumentation includes a variety of microphone systems,

ampli-fiers, spectrum analyzers, recorders and other ancillary instrumentation. 31

W

N

IMPLOSION DYNAMICS LABORATORY

A 20-cm-diameter hemispherical implosion chamber (left photograph) is the major piece of equipment. The chamber is machined into a massive steel bloek, which is covered by a massive steel plate, both fastened together by thirty-two 3.8-cm-diameter bolts. A stoichiometrie hydrogen-oxygen mixture (up to 60 atm)

is detonated at the centre by a short exp10ding nicke1 wire (1 mil diameter by 1 mm long). The detonation

wave initiates a hemispherical shell of PETN at the chamber periphery and a powerfu1 implosion fo11ows. This is the only laboratory capable of producing stable, focussed, explosive-driven implosions in a safe

reusable facility. It has been used to accelerate projectiles to hypervelocities (6000 mis), to generate

strong planar shock waves (20,000 mis) in a 2.5-cm-diameter channel, to produce diamonds by compressing

graphite, and recent1y to generate neutrons and gamma rays from D-D fusion reactions by uti1izing chemical energy on1y. Other new materials cou1d we11 be generated through solid-phase transitions. An image

con-verter camera, a Hi1ger medium quartz spectroscope with an 8-photoce11 Strassheim attachment, piezoe1ectric

gauges, manganin gauges and pure iron "witness plates" are used for measuring temperatures and pressures as functions of radius and time. The photograph on the right shows a more advanced design of implosion chamber,

w w

INSTITUTE COMPUTERS

The Institute has a computer terminal directly linked to the large IBM 3033 (MVS) digital computer

on the main (St. George) campus. This is accomplished by a general purpose IBM 1130 digital com-puter which also has a stand-alone capability and which may be used to drive a Calcomp plotter. Other more specialized analog and digital computers are used in specific research programs at the Institute. Several other computers at the main (St. George) campus are also available to UTIAS '

researchers, in particular, an IBM 370-165-11, a powerful DECSYSTEM 1090, an IBM 3031, and, for graphics and communications research, a DEC GT44 system and two Z-BO based microcomputers. A full-time computer coordinator is available to assist in resolving computational difficulties.

w

-l==>

LASER LABORATORY

The Institute's Laser Laboratory currently uses one nitrogen laser, two nitrogen laser pumped tunable dye

lasers, one flashlamp pumped tunable dye laser and one Q-switched pulsed ruby laser. These lasers are used

in a variety of projects and form the backbone of two main facilities: the Laser Ablation and Selective Excitation Spectroscopy (LASES) facility and the Laser Interaction Based on Resonance Saturation (LIBORS)

facility. The LASES facility has recently been shown to be capable of undertaking several experiments

ranging from the measurement of atomie radiative lifetimes to the study of plasma conditions. This facility

has also served as the work horse of a new approach to trace element analysis. The LIBORS facility will be

used to study a new kind of laser ionization and heating technique based on resonance saturation of an atomie vapor. Of particular interest is the possibility of creating long plasma channels that could be used for transportation of electron and light ion beams in future inertial fusion schemes and the development of an

w

(J'1

SHELL MECHANICS

SPACE SIMULATOR

AIRCRAFT CRASH FACILITY

STRUCTURES end MATERlALS

LABORATORY

The major facilities contained in this laboratory include a universal tension/compression testing machine (60,000 lbs capacity), a thermal-vacuum space simulator, capable of 10-7 torr with in-situ loading, a 13 foot long high pressure gas gun for impact studies, fatigue machines, a belt-wrapper apparatus and autoclave for manufacturing c08posite structures and an aircraft fuselage (~1/3 scale) drop test facility for investi-gating crash response.

W

0'1

TRACE GAS ANALYSIS LABORATORY

The laboratory is centred around a highly flexible atmospheric pressure chemical ionization mass spectrometer system. This has different inlets to be able to accept different samples such as ambient air, gas chromatograph effluents, volatized liquid samples, etc. It is currently capable of detecting many trace organic substances in air at parts per trillion concentrations instantaneously in real-time. Developmental research is steadily improving its performance. The facilities also include a variety of developmental vacuum chamber quadrupole mass spectrometers, ion sources, an electron multiplier test facility, analogue and digital electronic equipment, and a dynamic calibration facility capable of a9ding known trace amounts of organics to air, in the ppm to ppt range. The laboratory is currently engaged in applications research in biomedical, military and environmental areas. A basic program to provide better understanding of the transmission of ions into, through and out of quadrupole mass filters has been initiated as a collaborative project with the Physics Division of NRC, aimed at innovative improvements in this important technology.

PROGRESS REPORTS

AEROACOUSTICS Principal Investigators: Ph.D. Students: M.A.Sc. Students: Visiting Scientist:

G. W. Johnston, H. S. Ribner, W. G. Richarz B. Eatock, D. Noble, R. L. M. Wong

E. Della Penna, J. C. C. Ho, S. E. Keith

Z. Hu (Nanking Aeronautical Institute)

AIAA DRYDEN LECTURE 1981 (AIAA Aerospace Sciences Meeting, St. Louis, Jan.

12-14) The written form of this lecture by H. S. Ribner was prepared as

AlAA Paper No. 81-0428, "Perspectives on Jet Noise". It appeared, with nominal revision, in the December 1981 issue of AIAA Journal. The paper starts with a simple physical model of jet noise generation. This leads into a conceptual comparison of the Lighthill and Lilley theories: of two different roles for the mean-flow shear. Other topics are instability waves, density (Heating) effects, flight effects, effects of shock waves, and

suppression concepts.

ACOUSTICS OF THUNDER Further demonstrations of our "computer model made audible" have been given in presentations at two conferences: 100th Meeting, Acoustical Society of America, Los Angeles, Nov. 17-21,1980 (Paper B5,

presented by D. Roy) , and AIAA 7th Aeroacoustics Conference, Palw Alto, Oct. 5-7, 1981 (presented by H. S. Ribner). For the second meeting a com-prehensive account of the research plus new material on spectra was prepared and issued as AIAA Paper No. 81-1984. We emphasize that demonstrated realism of the computer thunder is ,not an end in itself, but rather one of several tests of the credibility of the underlying physical model.

SHIELDING CONCEPTS FOR JET NOISE (NSERC) Jet noise reduction via solid and gaseous shields has been investigated experimentally and theoretically. The study suggests that the engine-over-wing concept incorporating certain re-finements exp10red in our work offers considerable development potential. The results are reported in detail in the Ph.D. dissertation of R. L. M. Wong. Additional information is available in items 4 and 6 of the recent publications.

DIAGNOSTICS OF FORWARD FLIGHT EFFECTS (NSERC, University of Toronto) Our understanding of the influence of forward flight on jet noise is in part due to lack of a detailed description of the nature of the turbulent flow field of the moving jet. This investigation simulates forward flight by placing a streamlined model air jet in the test section of the anechoic wind tunnel. Our measurements indicate that the response of the local turbulent length and time scales is governed not only by the forward flight velocity, but also relative nozzle-eddy separation.

THE FLOW FIELD OF AN ACOUSTICALLY EXCITED JET (University of Toronto) When a subsonic jet is excited by acoustic waves, the turbulence levels may increase or decrease. A series of exploratory measurements has been per-formed in our duet flow facility on a 10 cm air jet operated at Mach number

.15. Excitation at frequencies greater than 2 kHz' "ca lms" the turbul ent flow. The impact on the length and time scales which govern the radiation efficiency of the sourees of jet noise is now under investigation.

SOUND FROM LARGE SCALE STRUCTURES IN A JET FLOW (NSERC) The i ssue of sound from large scale structures is a controversial one. We propose to

settle matters once and for all by direct measurement. To this end a unique large scale detection system is being designed around a Laser Doppler Veloci-meter. The output of the detector triggers phase averaging of the acoustic far field signal. Thus the phase-locked sound from the large scale struc-tures should be detected.

FURTHER DEVELOPMENT OF RIBNER'S SELF AND SHEAR NOISE MODEL (NSERC; J.IAFSJ

Dr. Richarz has spent part of the summer at NASA Langley, sponsored by George Washington University and the Joint Institute for Advancement of Flight Sciences. During that time he extended the jet noise theory pioneered by Ribner to the case of forward flight. In addition progress was made in the area of sound from heated jets. The analytical program is being continued at UTIAS.

RECENT PUBLICATIONS

1. H. S. Ribner, AIAA Dryden Lectureship in Research, "Perspectives on Jet Noise", AlAA-81-0428, 17 pp., Jan. 1981.

2. D. Roy, H. S. Ribner, "Acoustics of Thunder lIl: Mapping the 3-Dimensional

Shape of Lightning into the Sound of Thunder (with Audible Demonstration)", J. Acoust. Soc. Amer., Supp. 1,68, Fall 1980, Paper B5, pp. S3, S4 (Abstract). 2. H. S. Ribner, D. Roy, "Thunder from Tortuous Lightning: A Computer Model

Made Audible", AIAA-81-1984, 12 pp., Oct. 1981.

4. R. L. M. Wong, W. G. Richarz, H. S. Ribner, "Shielding Concepts for Jet Noise", AlAA Paper 81-2020, Oct. 1981

5. W. G. Richarz, S. E. Keith, "Acoustic Power of Jets", J. Acoust. Soc. Amer., Vol. 69, Sl, 1981.

6. W. G. Richarz, R. L. ~~. Wong, "Correction for a Class of Approximate

Dif-fraction Solutions", J. Acoust. Soc. Amer., Vol. 70, Sl, 1981.

7. W. G. Richarz, C. K. Shi, "Acoustic Nearfield of an Axisymmetric Jet", J. Acoust. Soc. Amer., Vol. 70, Sl, 1981.

8. W. G. Richarz, "Lecture and Laboratory Demonstrations for General Acoustics", J. Acoust. Soc. Amer., Vol. 69, Sl, 1981.

9. J. C. C. Ho, "Turbulence Measurements Relevant to Flight Effects on Jet

Noise", M.A.Sc. Thesis, Oct. 1981.

10. Z. Hu, "Jet Response to Pure Tone Excitation", UTIAS Tech. Note No. 232, 1981.

AIR CUSHION TECHNOLOGY Principal Investigator: Research Associate: Research Scientist: M.A.Sc. Students: Research Assistants: P. A. Sullivan M. J. Hinchey T. A. Graham

R. LeBlanc, D. Ribner, M. Simard A. Parker, S. Sorocky, B. Thompson

PITCH-HEAVE DYNAMICS OF A SEGMENTED SKIRT CUSHION (TDC, NSERC) The overall long term objective is to determine the extent to which mathematical models of various aspects of cushion dynamics developed in conjunction with other, simpler experiments such as those described below, can describe the complete dynamics of a realistically large vehicle. The skirt configuration currently being used has been chosen because, as skirts go, it has a relatively simple geometry.

Contributions are being made on such basic problems as the effect of visco-elastic properties of the materials used in skirt systems on the dynamics, and to the criteria for dynamic scaling of model tests. The flight test data is analysed by using a system parameter identification procedure (SPI) based on a response matching method, a maximum likelihood fit criterion and a Gauss-Newton iteration procedure. A linear system equation in the usual state form

x

=

8

~ + §y has to date been assumed, and for one skirt material , an 0.46

mm thick nylon-neoprene combination, the results obtained were consistent with static measurements of stiffness and hysteretic damping.

However, the SPI procedure only converges with considerable difficulty, and in some cases not at all; mainly, it appears, because we are attempting to identify too many parameters in one experiment. Also we have to alter the form of the mathematical system model in order to realistically describe certain highly nonlinear features of the skirt system. Finally, the task of analysis is complicated by the presence of the fan-induced gyroscopic torques which couple pitch to roll. The design of a new lift fan system to eliminate this and simplify the task of modelling dynamic fan behaviour is under way.

DYNAMIC INSTABILITIES OF AIR CUSHIONS (NSERC, TDC) Work on various factors that influence the dynamic stability of air cushions continues. An analytical investigation of the effect of acoustic wave propagation phenomena in the plenum chamber volume of very large platforms has been completed; it shows that under some circumstances these can be significant.9 _{A theoretical and}

experimental investigation of the viscoelastic properties of skirt material on the dynamic stability of a single slightly tapered conical cell has been completed.6 _{The experiments used the UTIAS 1000m}3 _{Vacuum Sphere to provide}

an idealized constant pressure air source and uncouple dynamic fan phenomena; large effects were observed. A theoretical and experimental investigation of a dynamic instability problem peculiar to vehicles hovering at rest over water has been completed; it shows that, for certain segment geometries, a type of low frequency Kelvin-Helmholtz instability in the boundary between the escap-ing air and water can couple with the vehicle heave dynamics. Work on the valving effect of segmented skirts, which, at equilibrium are always in par-tial contact with the ground, is also continuing. These experiments also use the UTIAS Vacuum Sphere facility. Finally, a start has been made on the inclusion of dynamic fan behaviour on cushion dynamics and stability. True unsteady fan response to an oscillating back pressure is being determined experimentally; this is to be incorporated in the stability model for suitable predictions.

A COMPLIANT SURFACE GAS BEARING CONCEPT FOR AUTO~TION OF GOODS HANDLING

SYSTEMS (TDC, NSERC, E. B. Eddy Forest Products) This system, currently being developed by E. B. Eddy Forest Products of Ottawa, should result in major innovations in goods handling and transport systems built around pallets and fork-lift trucks. The aim of our research is to provide an understanding of the way this system, with its unconventional features, operates in terms of basic ideas in fluid and structural mechanics, in order to lay a basis for further design improvement. Progress in understanding some aspects of the fluid mechanics has been made, but much is yet to be learned.

UNSTEADY POTENTIAL FLOWS IN ACV DYNAMICS (NSERC) Most calculations of ACV dynamics assume that the associated air flow processes are quasisteady, however it is likely that some, such as the trunk flutter or "skirt buzz" observed on some configurations, are not.2 _{This project continues to}

investigate unsteady potential flows for a number of simplified geometries in order to assess its practical significance.

FLOW LIMITATION IN AN ARTIFICIAL TRACHEA (MRC, NSERC) Air flow in the human lung-airway system of ten involves partial collapse of the trachea or other elements of the bronchial tree, especially during forced expiration. Associ-ated with this collapse is the phenomenon of flow limitation and the onset of self-excited oscillations, which generate sounds such as wheezing, which in turn have clinical significance. We have been able to reproduce these phenomena in a mechariical model which has some of the features of a human trachea. A preliminary analysis has been completed10 _{and experiments are} proceeding.

RECENT PUBLICATIONS

1. M. J. Hinchey and P. A. Sullivan, "A Theoretical Study of Limit Cyc1e Oscillations of Plenum Air Cushions", J. Sound and Vibration, 79, 1, 1981, P p. 61 -77 .

2. M. J. Hinchey and P. A. Su11ivan, "Kelvin-Helmholtz Stabi1ity Analysis of Air Cushion Landing Gear Trunk Flutter", J. Aircraft, 19, 1, 1982, pp. 94-96.

3. P. A. Su11ivan, M. J. Hinchey and G. M. Green, "A Review and Assessment of Methods for the Prediction of the Dynamic Stability of Air Cushions", J. Sound and Vibration, 84, 2, 1982.

THESES, UTIAS AND CONTRACT REPORTS

4. P. A. Su11ivan, M. J. Hinchey, G. J. Parravano and 1. Murra, "Research on the Stabi1ity of Air Cushion Systems", UTIAS Report No. 238, Nov. 1979.

5. M. J. Hinchey, "Heave Instabilities of Amphibious Air Cushion Suspension

Systems", UTIAS Report No. 246, Nov. 1980.

6. T. A. Graham, "Effect of Skirt Material Choice on the Heave Stability of an Air Cushion", M.A.Sc. Thesis, 1980.

7. A. D. Dupuis, "Flnite Element Analysis of the Wrinkling of a Circu1ar Cylinder", M.A.Sc. Thesis, 1980.

8. M. J. Hinchey, P. A. Su11ivan and T. A. Graham, "Research on the SailRail Compliant Surface Air Bearing", Transport Canada, Research and Development Centre Contract Report TP2817, Jan. 1981.

9. M. J. Hinchey and P. A. Sullivan, "Wave Propagation Effects on the Heave Dynamics of Larqe Air Cushion Platforms", UTIAS TN No. 234, Oct. 1981. 10. P. A. Sullivan, M. J. Hinchey, P. V. Hartmann, A. D. Dupuis and T. A.

Graham, "Research on Air Cushion Stability", Transport Canada, Research and Deve10pment Centre Contract Report TP3109E, Jan. 1982.

11. R. LeB1anc, "Study of Flow in an Artificial Trachea", M.A.Sc. Thesis, 1982.

FLIGHT AND GROUND TRANSPORTATION Principal Investigators: Research Scientists: Ph.D. Students: M.A.Sc. Students: Visiting Schol ar: L. D. Reid, B. Etkin W. O. Graf, A. M. Billing

S. G. Cavalcanti, A. B. Markov, E. N. Solowka

J. Byrne, K. W. Lam, A. Lanouette, Z. Liu,

R. B. MacKenzie, M. E. Rababy

S. Zhu (Beijing Institute of Aeronautics and Astronautics)

AIRCRAFT RESPONSE TO WIND SHEAR AND TURBULENCE DURING THE LANDING APPROACH (AES; NSERC; Air Canada) The study into techniques for generating worst-case

wind profiles has been completed and is fully documented in UTIAS Report No.

254. The investigation into the application of state-feedback wind controllers

to flight simulator trainers is continuing. Several of these wind controllers have been implemented on the laboratory's fixed-base manned simulator and

evaluated by test pilots for realism and potential usefulness in training

air-crew under adverse wind conditions. Following the initial success of this study work is currently underway, in conjunction with Air Canada, to further evaluate the technique in an operational flight simulator of the type employed by airlines. In conjunction with this work a project has been initiated to

study how rapidly pilots adapt to the wind conditions generated by the wind

controllers employed in these tests.

ADVANCED RESEARCH SIMULATOR DEVELOPMENT (NSERC; Air Canada) Our present simul-ator facility will soon be upgraded by the incorporation of a synergistic six-degrees-of-freedom motion base and a DC8 cab. In support of this operation a literature survey is in progress in the areas of linear, nonlinear and adaptive washout filter algorithms for use in limiting the simulator motion. This is required in order to keep the cab within the physical constraints of the hardware without inducing false motion cues in the pilot. Also, in order to reduce the load on the present computer facility, the use of microprocessors in operating the simulator is under study.

In upgrading the simulator, its ability to represent ground vehicles will be retained. A suitable work station will be included in the cab design.

AUTOMWTIC LANDING OF LARGE JET TRANSPORTS (CNPq, Min. Aer. Brazil) With the introduction of MLS (Microwave Landing System) at major airports and the antici-pated widespread use of autoland systems there will be increased interest in the autoland certification process. This will be applied in the preliminary stages of the evaluation of such systems. The present research deals with the extension of the worst case wind models to the landing flare and touchdown. With this extension a complete landing model will be obtained for use in the autoland certification problem. At the present time the extension of the wind generation computer codes to cover this case is in progress.

MODELLING OF THE DRIVER/ROAD VEHICLE SYSTEM (MTC; MOT; GM) Advancing technology

produces complex, high performance machines that are both more costly to operate and require a greater operator training effort than conventional man/machine systems. Vehicle simulators introduced into training programs as a solution to these problems, as well as simulators designed to investigate human performance in advanced or experimental vehicle systems are of research interest in the aspects of transfer of learning and the prediction of performance in an actual vehicle from data obtained in a simulator.