Whether predicting the turbulent motion of boiling water, next week’s weather, or future energy production technologies, the varied consequences of fluid motions on human activity are undeniable, with the role played by predictive computations dramatically increasing. Our approach to computing fluid flows, the Entropic Lattice Boltzmann Method (ELBM) is inherently physical and deeply rooted in statistical mechanics, with a kinetics framework translated onto a lattice in position, momentum, time and space. It is coupled closely with new computational ideas that enable predictive simulations in extremely complex geometries more efficiently, accurately, and robustly than heretofore possible. Research work of Computational Kinetics Group will impact a wide range of contemporary problems, from the design of fuel cells and vacuum valves to aircraft design.
The core activity of the Computational Kinetics Group is to extend and apply these recently developed kinetic methods to solve a broad swath of these fluids problems and thereby open new vistas for fluid science and technology. The ELBM approach is inherently computational and, without modern computers, it could not (and would not) be competitive with classical continuum methods.
Our goal is to demonstrate – through development of new ELBM models in various sectors of fluid dynamics and predictive simulations - that ELBM opens up a new horizon of flow computations. Indeed, LB methods are perhaps still viewed with suspicion by many CFD experts still questioning their utility and validity relative to more classical finite-difference, finite-element, or spectral techniques. That is unfortunate since we believe that ELBM belongs in the tool kits of CFD for a number of reasons including accuracy, speed, parallelizability, stability, robustness, ease of geometry and boundary condition implementation, and ease of extension to problems beyond the standard hydrodynamics.
Hence, our effort is to explore in-depth the entropic lattice Boltzmann methods, which are still research tools and certainly not yet commercially available, to become an essential part of the tool-kit for fluid dynamics simulations and thereby to revolutionize the field of computational fluid dynamics. The impact of this development will be not only to open new vistas for computational fluid dynamics of complex flows but also and to increase widely the range of scientific problems that can be effectively addressed by computations. When compared to conventional approaches such as spectral finite element methods, the ELBM clearly promises to be far more scalable on future multicore computers at the petascale and beyond. This makes the ELBM an ideal framework to demonstrate that this new kind of 21st century science is likely to have the most impact and influence on the future of scientific and technological endeavors.
Present activities of the Computational Kinetics Group are focused effort to achieve the major breakthrough in the following major directions: direct simulation of turbulence, compressible flows (including reactive flows), multiphase flows and micro-flows. Established success of ELBM in these three domains will boost the research in other areas of fluid dynamics such as biological flows, relativistic and complex fluid flows etc. where the applications of LBM are currently under development.
Recent achievements include the development of a novel lattice Boltzmann model for multiphase flows  and its applications to study novel microfluidics phenomena such as drop impact on textured hydrophobic and sublimating surfaces; novel entropic lattice Boltzmann models for direct simulation of incompressible [2,5,10] thermal , compressible , and most recently also transonic and supersonic flows; and powerful model reduction techniques for realistic hydrocarbon combustion mechanisms [3,8]. Computational Kinetics Group maintains strong research relations to various experimental groups at ETH.
Computational Kinetics Group was established in 2012 under the ERC Advanced Grant “Frontiers of Multi-Scale Fluid Dynamics” and is funded through the ERC, SNSF and ETH Research grants.
Selected recent publications:
- Mazloomi M, S.S. Chikatamarla and I.V. Karlin, Entropic lattice Boltzmann method for multiphase flows, Phys. Rev. Lett. 114, 174502 (2015)
- B. Dorschner, F. Bösch, S.S. Chikatamarla and I.V. Karlin, Grad’s approximation for moving and stationary walls in entropic lattice Boltzmann simulations, J. Comput. Phys. 295, 340-354 (2015)
- M. Kooshkbaghi, C.E. Frouzakis, K.B. Boulouchos and I.V. Karlin, n-Heptane/air combustion in perfectly stirred reactors: Dynamics, bifurcations and dominant reactions at critical conditions, Combustion and Flame, in press (2015)
- O. Furtmaier, M. Mendoza, I. Karlin, S. Succi and H. J. Herrmann, Rayleigh-Benard instability in graphene, Phys. Rev. B 91, 085401 (2015)
- I.V. Karlin, F. Bösch and S.S. Chikatamarla, Gibbs’ principle for the lattice-kinetic theory of fluid dynamics, Phys. Rev. E 90, 031302(R) (2014)
- N. Frapolli, S.S. Chikatamarla and I.V. Karlin, Multispeed entropic lattice Boltzmann model for thermal flows, Phys. Rev. E 90, 043306 (2014)
- A.N. Gorban and I. Karlin, Hilbert’s 6th problem: Exact and approximate hydrodynamic manifolds for kinetic equations, Bull. American Math. Soc. 51(2) 187–246 (2014)
- M. Kooshkbaghi, C.E. Frouzakis, K.B. Boulouchos and I.V. Karlin, Entropy production analysis for mechanism reduction, Combustion and Flame 161, 1507–1515 (2014)
- I.V. Karlin, D. Sichau and S.S. Chikatamarla, Consistent two-population lattice Boltzmann model for thermal flows, Phys. Rev. E 88, 063310 (2013)
- F. Bösch and I.V. Karlin, Exact lattice Boltzmann equation, Phys. Rev. Lett. 111, 090601 (2013)