SC²S Colloquium - May 6, 2015

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Date: May 6, 2015
Room: 02.07.023
Time: 3:00 pm, s.t.

Sergey Zakharov: Hybrid Lattice Boltzmann-Molecular Dynamics Simulations Using the Palabos and OpenLB Frameworks

The evolution of nanotechnology made it possible to produce tiny devices used for various multidisciplinary applications, e.g. biosensors, DNA chips, lab-on-a-chip devices, etc. Many of these devices are operating in aqueous environments and affect the flow. In order to develop and produce them, one has to first understand their behavior using a molecular dynamics simulation. But even with the use of the top-notch parallel supercomputing systems, the reachable size of the simulated volume is relatively small. A solution to this problem lies in a hybrid approach, where the simulation domain is divided into two regions: the first covers a bigger size and is resolved using a much cheaper, but less accurate continuum simulation; the second one is evaluated using a molecular dynamics simulation. The solvers of the hybrid system are coupled together and interact with each other by sending certain physical values which have to be properly adapted since the solvers work on different scales. This approach offers a good compromise between high computational complexity and physical accuracy.

In this work two popular open-source Lattice Boltzmann frameworks, OpenLB and Palabos, were coupled together with the molecular dynamics simulation using the Macro-Micro-Coupling tool. The coupling was established and validated using a standardized three-dimensional channel flow scenario. The code was further extended to support the parallel execution, since this feature is essentially important for these computationally expensive simulations. The performances of the coupled simulations, using the mentioned frameworks, were evaluated and compared to each other.