From 2011, Baichuan Sun started his journey as a PhD student under Professor Anutosh Chakraborty, in Thermal and Fluids Engineering at Nanyang Technological University (NTU), Singapore. His research topics focus on developing novel adsorption isotherm and kinetics models from viewpoints of both classical and statistical thermodynamics. He is also largely interested in establishing new knowledge in rarefied gas dynamics, lattice Boltzmann method, and micro/nano-scale transport during his research. His work is fundamentally significant for various low carbon footprint applications including adsorbed natural gas storage (ANG), adsorption chiller, desalination, nanostructured thermoelectric device and hydrogen driven vehicle, etc. Prior to his PhD study, Baichuan spent half a year as a research student at Tohoku University, Japan. He received his bachelor’s in mechanical engineering from Huazhong University of Science and Technology, China in 2010. Baichuan is an enthusiast of soccer, and he is very good at Chinese calligraphy, painting, and seals.
Project: Adsorption Isotherms and Kinetics Simulation with Lattice Gas Cellular Automaton
Adsorption phenomena are increasingly utilized to perform separation processes, adsorption chilling, hydrogen-driven vehicles, and more recently gas storage. The physical adsorption process occurs mainly within the pores of the external adsorbent surface due to van der Waals’ force field. The amount of adsorbate uptake depends on the nature of adsorbates and the porous adsorbent structure. For higher adsorptive capacity, the adsorbents should have a high surface area and/or high micropore volume, with an optimum pore width distribution that spans from super micropore to mesopores. However, the porous medium is naturally associated with very small pores and adsorbate molecules have to find their way to the interior surface area or micropore volume. This path-finding gives rise to the so-called diffusional resistance towards molecular flow within scope of adsorption kinetics.
Lattice Boltzmann method (LBM), stemming from cellular automata, is a fluid dynamic simulation method that is conceptually simple, and can be applied to deal with thermal interface effects to a wide array of boundary conditions. LBM has been successfully used to model a number of typical fluid dynamic problems within macroscope. However, it should not be too difficult to extend LBM into microscopic scale with surface adsorption reaction. The objective of this project includes:
1) Construct 2/3D porous network structure with parameters corresponding to pore width and volume distribution, which could simulate adsorbent materials including activated carbon, zeolite, etc.
2) Define simple LBM rules that describe gaseous phase molecule behavior of collision and diffusion.
3) Determine rules for surface stickiness effect between adsorbate gaseous phase molecules and solid adsorbent material surface.
4) Quasi-equilibrium thermodynamic boundary conditions would be given for simplification.
5) Visualize the relationship between gaseous phase molecules uptake and cellular automaton steps.
Favorite Four-Color, Four State Turing Machine