Research - Science & Engineering
Throughout my life, I have found the natural world to be a source fascination and inspiration. Thus, it is not surprising that science and engineering are strong undercurrents in my research. I am always on the look out for opportunities to use the methods and techniques of computational science & engineering and applied mathematics to further our understanding of the world around us.
My research in science and engineering have been focused in the following areas:
Within these areas, I am currently working on
- Characterization of microstructure in polycrystalline materials (Material Science)
Computational Material Science
Microstructure of Polycrystalline MaterialsCollaborators: S.S. Jerry Quek, David T. Wu, Chin Yi Chee
Phase Field Modeling of Polycrystalline MaterialsCollaborators: S.S. Jerry Quek, David T. Wu, Chin Yi Chee
Dislocation Dynamics and Grain Boundary EvolutionCollaborators: David J. Srolovitz, Mikko Haataja, S.S. Jerry Quek, Zi Chen, Adele Lim
Understanding the role of dislocations and grain boundary evolution in the plastic deformation of materials continues to present an important and interesting challenge for material scientists. We studied both of these microstructural entities using mesoscopic computational models based on the level set method.
In our model, dislocations are represented by the intersection of the zero level sets of two level set functions. An important consequence of this implicit representation of the dislocation line is that topological changes that occur when dislocation lines interact with obstacles and with each other take place automatically without requiring complicated ``surgical procedures.''
To address the computational complexity of modeling dislocation networks and grain boundaries using the level set method, we have implemented the Level Set Method Dislocation Dyanmics (LSMDD) library. This software library is designed to support high-performance, parallel computation and to be modular enough to allow for exploration of novel numerical models and algorithms for simulating dislocation dynamics and interactions.
- Working notes
- Constructing Dislocation Models of Low-Angle Grain Boundaries. K. T. Chu and A. T. Lim. (2007)
BiophysicsCollaborators: Keng-Hwee Chiam
Electrochemical TransportCollaborators: Martin Z. Bazant
Novel electrochemical devices being explored for microfluidic and micro/nano-power source applications often electrochemical systems into operating regimes that test the limits of traditional macroscopic theories in electrochemistry. We study electrochemical transport in these extreme operating regimes by analyzing the classical Poisson-Nernst-Planck equations using asymptotic analysis and numerical simulations.
One of the main conclusions of our work is that for weak electrolytes, large concentration gradients develop even at relatively small applied electric fields/voltages. These concentration gradients imply that the common approach of modeling electrochemical transport using linear circuit models is questionable for systems driven by strong electric fields/voltages.
Using novel asymptotic analysis techniques, we have also formally derived effective nonlinear electrochemical transport equations in the thin double-layer limit, which generalize linear circuit models. The foundation for this work is a novel formulation of surface conservation laws which allows us to derive effective boundary conditions that capture the physics of the double layer without requiring linearization of the concentration and potential fields.
Current-voltage relations for electrochemical thin films.
M. Z. Bazant, K. T. Chu, and B. J. Bayly.
SIAM J. Appl. Math. 65, 1463-1484 (2005).
Electrochemical thin films at and above the classical limiting current.
K. T. Chu and M. Z. Bazant.
SIAM J. Appl. Math. 65, 1485-1505 (2005).
Nonlinear electrochemical relaxation around conductors.
K. T. Chu and M. Z. Bazant, Phys. Rev. E, 74, 011501 (2006).
Surface Conservation at Microscopically Diffuse Interfaces.
K. T. Chu and M. Z. Bazant,
J. Colloid Interface Sci., 315, 319-329 (2007).