Abstract:
Multiphase flow reactors are widely used in process and energy industries. Understanding the complex phenomena of gas-particle flows is necessary when developing or improving many reactive and separation
processes. With state-of-the-art modelling and simulation tools, a better understanding and insight of the process can be developed. In the past few decades, computational fluid dynamics (CFD) has proven very valuable to increase our understanding of gas-solid flows. However current multiphase CFD models are limited to small scale reactors due to their computational complexity. New coarse-grained gas-particle models are emerging that can handle large scale systems. I will talk about how multiphase CFD models are efficiently developed and used to study large scale systems with complex geometries. In specific, I will present an efficient two-fluid model based on kinetic theory of granular flow for a cylindrical fluidized bed. The experimental study of gas-solid fluidized beds using ultra-fast electron beam X-ray tomography, that validates the TFM simulation. I will discuss filtering (coarse-graining) of two fluid model to handle industrial scale fluidized beds. I will show an example of CFD simulations for a large-scale multistage fluidized bed CO2 capture unit. Further, I will talk about discrete particle model (CFD-DEM) and a novel lagrangian coarse-grained solid-stress-based particle collision model, called continuum particle model (CPM). In CPM particle-particle collisions are efficiently captured using a continuum solid stresses approach rather than tracking discrete particle-particle collisions.
Bio:
Since January 2017, Vikrant is working as a postdoc researcher with Prof. Johan Padding in the Process & Energy Department at Delft University of Technology, The Netherlands. Prior to this, he spent two years as an independent postdoc researcher at the Multiphase Flow Science, National Energy Technology Laboratory (NETL), DOE, USA. In 2014, he received his Ph.D. degree in “Modeling, Simulations and Experimental Studies of Gas-solid Cylindrical Fluidized Beds” from Eindhoven University of Technology, The Netherlands under the supervision of Prof. J.A.M (Hans) Kuipers. In year 2010, he graduated with his Dual Degree (B-Tech in chemical engineering and M-Tech in computer applications in chemical engineering) from the Indian Institute of Technology, Delhi. His research area includes multi-scale modelling of gas-particle flow, with a focus on developing large scale CFD models for complex geometries. Validation of CFD model with non-invasive measurement techniques such as particle image velocimetry, X-ray tomography and electrical capacitance tomography. He has developed in-house CFD codes (1) Two-fluid model based on kinetic theory of granular flows and (2) Lagrangian coarse-grained solid-stress-based particle collision model, called Continuum Particle Model (CPM). He developed a gas-solid sub-grid drag model for immersed vertical tubes in fluidized beds.