U of R ME : Faculty-Gans

Roger F. Gans

Professor of Mechanical Engineering
Hopeman 330
Phone: (585) 275-2123, Fax: (585) 256-2509, gans@me.rochester.edu

Ph.D., University of California, Los Angeles (1969), S.B., Massachusetts Institute of Technology (1963)

My research is currently focused on the engineering applications of magnetorheological fluids (MRF). Much of the work is carried out in cooperation with the Center for Optics Manufacturing (COM). COM is investigating the use of magnetorheological fluids in lens polishing. I am looking at model flows using lubrication approximations and a Bingham model of the MRF to identify critical issues, domains and parameters for this process. Current issues include variable yield strength and large yield strength. The latter changes the lowest order behavior of any asymptotic solutions. We are also looking at frame invariant models incorporating the directionality of the applied magnetic field. My direct contribution is primarily analytic, and students are pursuing related experimental and numerical paths.

On occasion I treat myself to some research in dynamical systems. The discovery of apparently random behavior in deterministic systems in the early 1960's has led to renewed effort in classical and neo-classical dynamics, with a view to finding so-called chaos everywhere. Chaos does appear to be ubiquitous, but its diagnosis and treatment is not easy. My work is directed at the application of modern dynamical systems theory to the world of engineering, particularly realizable devices. Thus there is an emphasis on modeling systems and processes in the real world as well as observing real systems with a view to chaos detection. I have been able to apply this to deterministic grinding processes at Com, looking at the nonlinear coupling between various cutting tools and work pieces, themselves modeled as linear oscillators. Detailed models of the cutting process will be required in the near future. I am also interested in the general problem of linear oscillators coupled in a nonlinear fashion and in the dynamics of the biologically interesting collapsible tube osillation, although I am not actively pursuing this at the moment. Finally I was able to do some interesting dynamical simulations of the Levitron. (The number of web pages dealing with th eLevitron is immense; I leave it to the browser to chase these down.)

Representative Publications

On the Dynamics of a Conservative Elastica Pendulum, ASME J. Appl. Mech. Vol.59 (2), pp.425-430, (1992).
Efficient Search for Robot Skill Learning: Simulation and Reality (Schneider, J. and Gans, R. F), Proceedings of the IEEE International Conference on Intelligent Robots and Systems (1994).
When is Cutting Chaotic? J Sound and Vibration188(1) 75-83 (1995)
The Influence of Material Removal Models on the Dynamics of Cutting and Grinding Machines (Gans, R.F.), Proc. Intl. Conf. on Optical Fabrication & Testing, SPIE 2576, 12-23 (1995).
Dynamic Model for Microgrinding Spherical Optical Surfaces (Venkataram, N., & Gans, R.F.), Proc. Intl. Conf. on Optical Fabrication & Testing, SPIE 2576, pp. 58-67 (1995).
Adapation of Traditional Grinding Force Models to Cylindrical Cup Grinding (Venkataraman, N. & Gans, R.F.), Optical Fabrication and Testing 7 OSA Technical Digest Series (Optical Society of American, Washington, D.C.) pp. 98-101 (1996).
A Control Algorithm for Automated Pursuit (Gans, R.F.), 1997 IEEE Conf. Control Application, Hartford, CT, pp. 907-911 Proc. Oct. 5-7, 1997 (1997).
Simple Theory for the Levitron^TM(Jones, T.B., Washizu, M. & Gans, R.F.), J. Appl. Phys. (1997).
Dynamics of the Levitron^TM (Gans, R.F., Jones, T.B. & Washizu, M.), J. Phys. D. 31 671-679 (1998).
On the Flow of a Yield Strength Fluid Through a Contraction (Gans, R.F.), J. Non-Newtonian Fluid Mech 81 183-195 (1999)
Design and Testing of a New Magnetorheometer (Shorey, A. B., Kordonski, W. I., Gorodkin, S. R., Jacobs, S. J., Gans, R. F., Kwong, K. M. & Farny, C. H.) Rev Sci Instrum (submitted May 1999)

"For additional information, go to my personal webpages."