Some remarks on modeling fluid-infiltrating, thermal-sensitive, and partially-frozen porous media across length scales
Applied Mechanics Colloquia
Steve WaiChing Sun, Columbia University
Wednesday, March 23, 2016 - 4:00pm to 5:00pm
Many engineering applications, such as geological disposal of nuclear waste, require reliable predictions on how porous media responds to extreme environments. This presentation will discuss the relevant modeling techniques designed specific for porous media subjected to such harsh environments. In particular, we will discuss (1) a finite strain finite element model that captures the freeze-thaw action of frozen soil, (2) the stability and dispersion analyses that reveals the vanishing of physical length scale of thermal-sensitive porous media at short wavelength limit, (3) the usage of multiscale techniques to link grain-scale simulations to macroscopic predictions and hence bypass the usage of any macroscopic phenomenological law. Spurious pathological predictions by previous DEM-FEM models are examined and the remedies are proposed.
Speaker Bio: WaiChing Sun is an assistant professor in the Department of Civil Engineering and Engineering Mechanics at Columbia University. Prior to joining the Columbia faculty, he is a senior member of technical staff at Sandia National Laboratories. Professor Sun works in the fields of theoretical and computational poromechanics with a special emphasis on geomechanical applications. His research includes multiscale modeling porous media, multiscale verification and validation with CT images, digital rock and granular physics, applications of mathematical tools, such as graph theory, Lie algebra for modern engineering problems. He received the Dresden Junior Fellowship in 2016, Army Young Investigator Program Award in 2015, and the Caterpillar Best Paper Prize in 2013. He holds BS degree from UC Davis, MS degrees from Stanford and Princeton and PhD degrees from Northwestern.