Professor
Office: MATH 229B
Email: wachs@mail.ubc.ca
Website: https://personal.math.ubc.ca/~wachs/
Research Summary
Fluid mechanics, Particle-laden flows, Non Newtonian flows, Heat and mass transfer, Numerical simulation, High performance computing, Multi-scale modelling, Machine Learning
Education
Institut National Polytechnique de Toulouse, 2010, HDR
Grenoble, 2000, Ph.D.
Grenoble, 1997, M. Fluid Mech.
Louis Pasteur University, Strasbourg, 1996, B.Eng.
Research interests + projects
Our group is interested in extending the understanding of the dynamics of granular and particle-laden flows through the analysis of data produced by numerical simulation. Our work is interdisciplinary and we contribute to the following three broad areas: (i) development of in-house massively parallel scientific codes based on advanced numerical methods, (ii) mechanics of granular materials made of non-spherical particles, and (iii) multi-scale analysis and design of reduced-order models of particle-laden flows. Applications of particle-laden flows are ubiquitous in nature and industry, ranging from sediment transport in rivers in earth and ocean science, fluidized bed chemical reactors in process and chemical engineering to drug transport in the human blood system of veins and capillaries in biomedical engineering. I advise graduate students in the departments of Chemical and Biological Engineering and Mathematics, I am an associate member of the department of Computer Science and a member of the Laboratory for Complex and Non-Newtonian Fluid Flow. Parallel computations are run on the Compute Canada Cedar and Niagara supercomputers and on the local UBC Sockeye supercomputer.
Scholarly and professional activities + affiliations
Communications in Computational Physics 2021
Journal of non-Newtonian Fluid Mechanics 2015
Selected publications + presentations
C. Selcuk, A. Ghigo, S. Popinet and A. Wachs. A fictitious domain method with distributed Lagrange multipliers on adaptive quad/octrees for the direct numerical simulation of particle-laden flows, Journal of Computational Physics, 430, 109954, 2021. https://doi.org/10.1016/j.jcp.2020.109954
A. Seyed-Ahmadi and A. Wachs. Microstructure-informed probabilistic point-particle model for hydrodynamic forces and torques in particle-laden flows, Journal of Fluid Mechanics, 900, A21-1-38, 2020. https://doi.org/10.1017/jfm.2020.453
A. Wachs. Particle-scale computational approaches to model dry and saturated granular flows of non-Brownian, non-cohesive and non-spherical rigid bodies, Acta Mechanica, 230, 1919-1980, 2019. https://link.springer.com/article/10.1007/s00707-019-02389-9
A. Wachs, L. Girolami, G. Vinay, and G. Ferrer, Grains3D, a flexible DEM approach for particles of arbitrary convex shape – Part I: numerical model and validations, Powder Technology, 224, 374-389, 2012. http://dx.doi.org/10.1016/j.powtec.2012.03.023
Z. Yu, X. Shao and A. Wachs. A fictitious domain method for particulate flows with heat transfer. Journal of Computational Physics, 217(2):424-452, 2006. http://dx.doi.org/10.1016/j.jcp.2006.01.016