Allen Anilkumar
Ph.D. Student
Allen is a 4th year Ph.D. student at the Department of Mechanical Engineering, Indian Institute of Technology Bombay (IITB). His research interests are in the areas of dynamics and vibration with particular interest in parametrically excited systems.
For his doctoral research work, he investigates the vibrations of rotating machines with flexible rotors (especially those which are contra-rotating), modelled using lumped masses and/or continuous systems such as beams. The equations of motion of such systems turn out to be quasi-periodic in the rotor frequencies which exhibit rich dynamics and resonances which are unpredictable using classical techniques. The frequency spectra of time responses show distinct side-banded structures with peaks which are equally spaced at twice the forcing frequencies. Classical resonances (when the frequency of a rotor, matches with a natural frequency, for example when), fractional resonances (when) and proportional resonances (when) are investigated using analytical, numerical and experimental techniques. The study has prospective applications in the dynamics of helicopters, contra-rotating stages of gas turbines, cd/dvd drives, washing machines, etc.
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Figure 1: Transition curves for a contra-rotating machine, generated using the method of harmonic balance |
Figure 2: Waterfall plot of experimentally obtained frequency spectra |
Figure 3: The experimental setup
Figure 4: Locus of the planar position of a stator (on springs), excited by a rotating flexible beam
Publications
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Allen Anilkumar, V. Kartik. “Vibrations and stability of a rotating machine with a flexible rotor”. International Conference on Vibration problems, IIT Guwahati, Assam, India, December 2015.
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Allen Anilkumar, V. Kartik. “In-plane parametric instability of a rigid body with a dual-rotor system”. ASME International Mechanical Engineering Congress and Exposition, Houston, Texas, USA, November 2015.
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Allen Anilkumar, Anoop C. Vijayan, Arun Vijay, Ayyappadas P., N. R. Jaget Babu. “Prototyping of a novel, externally coiled magneto-rheological damper”. Indian Journal of Engineering, Science and Technology, 2010; Vol. III, Pg.40-45.
Biography
Allen received his B.Tech. Degree in Mechanical Engineering from the University of Kerala (in 2009) and M.E. Degree from the Birla Institute of Technology and Sciences, Pilani (in 2012).
Before joining IITB he worked on “Hysteretic Seat Design and Control of Passenger Vibrations using a Quarter-car Model” for his Masters dissertation. He has undertaken minor projects on bond-graph modelling of automobile-passenger systems and bio-mechanics of hip joints. He has also worked on the development of a coconut oil based magneto-rheological damper with applications mainly in the automobile industry. His spare-time activities include playing basketball travelling, cycling and gardening.