MIT Aero/Astro - Fredric Ehrich

Fredric F. Ehrich

Senior Lecturer
Gas Turbine Laboratory
Massachusetts Institute of Technology

Home Office: 58 Beacon Street
Marblehead, MA 01945
Tel: 781-631-1600
email: ffe@mit.edu

Campus Office:
Mass. Inst. of Tech.
Rm. 31-261G
Cambridge, MA 02139
email: ffe@mit.edu

Fredric F. Ehrich is the editor of "Handbook of Rotordynamics",http://www.krieger-publishing.com/html/stackengineering_55.html

Professional Experience
Dr. Ehrich's entire professional career has been dedicated to aircraft gas turbine technology with particular focus on rotordynamics. From 1951 to 1957 he worked for the Westinghouse Aircraft Gas Turbine Division in Philadelphia, PA and Kansas City, MO in engineering and engineering leadership positions in research, analysis, design and development including activities in aerodynamics, stress, and vibrations. As part of his duties, he spent the year 1955 to 1956 as Westinghouse's technical representative at Rolls Royce Aero Engines in Derby, England. From 1957 on, Dr. Ehrich was associated with GE's Aircraft Engine activity in Lynn, MA in senior engineering and engineering leadership positions. He led the design and development to flight service of the T64 turboprop/turboshaft engine, still in production and extensive service. He was also responsible for the design and development of the components for major growth and derivative models of then current production engines such as the J85 afterburner turbojet, the T58 turboshaft engine, the T64 turboshaft/turboprop and the CF700 aft fan engine, and led the design and development of the major components for such engines as the GE12 which evolved into the T700/CT7 turboshaft/ turboprop, the GE15 which evolved into the YJ101 and ultimately into the F404 and F414 afterburning turbofan engines, and the TF34/CF34 high bypass turbofan, all of which are now in mass production and powering aircraft world-wide. He has also held positions in preliminary design, product planning, and as a technical consultant and staff engineer.

Dr. Ehrich retired from GE in January 1994 and is still active in consulting and in teaching and research (on the gas bearings and rotordynamics of the MIT/GTL Micro-engine) as a Senior Lecturer at MIT.

Publications
Dr. Ehrich is the author of over 40 published technical papers. His major technical interest has been in the field of rotordynamics of high speed rotating machinery, and his original writings deal with such diverse topics as hysteretic whirl; fluid trapped in rotors; subharmonic, superharmonic and chaotic vibration phenomena; balancing; and several other aspects of nonlinear and unstable phenomena in high speed rotating machinery. He has also published articles on turbomachinery aerodynamics and on stress and stability problems in aircraft engines as well as their design and development. He is the author of the chapter on "Self-Excited Vibration" and a new section on "Nonlinear Vibration" of the McGraw-Hill Handbook of Shock and Vibration and of articles on "Turbine Propulsion" and various engine types in McGraw-Hill's Encyclopedia of Science and Technology. He is the editor-in-chief of and a principal contributor to the Handbook of Rotordynamics published in 1991 by McGraw-Hill and in a revised edition in 1999 by Krieger Publications. He is also the author of the article on the "Jet Engine" in the Encyclopaedia Britannica, co-author of an article on "Aircraft Engines" for the Encyclopedia of Energy Technology and the Environment, and author of an article on "Gas Turbines" for the Encyclopedia of Applied Physics. He holds 9 issued patents on aircraft gas turbine apparatus and one in micro-turbomachinery. Dr. Ehrich has delivered invited lectures to the National Research Council of Canada, the Chinese Academy of Science, National University of Korea, University of Nagoya, Singapore Aerospace Conference, the Czech Technical University, the Israel Institute of Technology (Technion) and at several universities and at meetings of international societies such as IFTOMM and ISROMAC.

Additional Professional Activities
Dr. Ehrich has been active in ASME activities as Editor of the Journal of Mechanical Design / Journal of Vibration, Acoustics, Stress and Reliability in Design, as Chairman of the Design Engineering Division and in the as Chairman of the Aircraft Engine Committee of the International Gas Turbine Institute. He has represented ASME on the ABET (formerly ESPD) engineering curriculum accreditation committee at various universities (1969-1977). He is also an Associate Editor of the International Journal of Turbo- and Jet-Engines, and is an Associate Fellow of the AIAA, a Regional Chairman of the MIT Education Council and is a Registered Engineer in Pennsylvania. He has been Program Chairman of several major professional society meetings including the 1st ASME Vibrations Conference (1967), National SAE Air Transportation Meeting (1977) and the 24th AIAA/ASME/SAE/ASEE Joint Propulsion Conference (1988).

Education
Dr. Ehrich received his professional training at the Massachusetts Institute of Technology, and was awarded his S.B. (1947), M.E. (1950), and Sc.D. (1951) degrees in Mechanical Engineering there. He spent the 1947-1948 academic year at the Delft Technical University in the Netherlands on a Dutch government fellowship. His doctoral work was accomplished on a Shell Fellowship.

Honors and Awards
Dr. Ehrich was elected to the academic honorary societies Tau Beta Pi, Pi Tau Sigma and Sigma Xi. Dr. Ehrich was elected to membership in the National Academy of Engineering in 1992. He is a Fellow of the ASME. In 1995, he was inducted into the GE Propulsion Hall of Fame.