Welcome to the regular seminars on current research topics in computational mechanics!

Presentations are given by invited lecturers from Skoltech as well as from outside to introduce students to current trends and advances in diverse areas of modern fluid and solid mechanics, applied mathematics, computational science, and industrial applications of mechanics. Students have the opportunity to learn from and interact with leading experts in computational mechanics and to enjoy exposure to cutting-edge topics and open problems in the field.

Seminars are held in English.

Lead Instructor: Aslan Kasimov, Associate Professor

Contacts: A.Kasimov@skoltech.ru

OCTOBER 9, 11:00 AM | DISPERSION RELATIONS FOR CONTINUOUS AND DISCRETE MODELS OF COMPRESSIBLE CONTINUUM MECHANICS 

Location: R2-2026
Speaker: Olga Stoyanovskaya, PhD, Senior Research Scientist at Lavrentyev Institute of Hydrodynamics, SB RAS; Director of the Bachelor’s program in Mathematical methods and information technologies in mechanics at Novosibirsk State University

Abstract: Mathematical models of processes in continuum mechanics, plasma physics and astrophysics are often nonstationary partial differential equations. To study such mathematical models and their discrete analogues, the technique of constructing dispersion relations has been developed. Dispersion relations describe wave processes (processes of perturbation transfer at a speed different from the velocity of motion of matter) in media. There is an algorithm that allows you to match a continuous or discrete model of continuum mechanics, plasma physics and astrophysics with a dispersion relation (classical or approximate, respectively). The report will show the possibilities of applying approximate dispersion relations to the development and research of numerical algorithms using the example of the computationally time-consuming task of modeling the dynamics of gas-dispersed media by the method of smoothed particle hydrodynamics (Smoothed Particle Hydrodynamics, SPH).

NOVEMBER 13, 2:00 PM | HYDRODYNAMIC STABILITY OF DENSE SUSPENSION FLOWS IN PLANE CHANNELS

Location: R3-2009
Speaker: Julia Klimenko, PhD student of Mathematics and Mechanics, Skoltech

Abstract: The study explores the stability of flows of dense suspensions in narrow channels. The motivation for this research lies in the widespread use of dense suspensions in oilfield service technologies, particularly in the process of hydraulic fracturing. The scientific significance of this work lies in identifying new mechanisms of instability in dense suspension flows. These suspensions vary in density from a rarefied suspension to a dense pack. A system of equations is formulated to describe the isothermal flow of a suspension with low-inertia particles in a flat channel using a single-speed model of interpenetrating continua.

NOVEMBER 20, 2:00 PM | SIMULATION OF POISEUILLE-TYPE FLOWS OF A VISCOELASTIC POLYMER FLUID, THEIR STABILIZATION AND STABILITY LOSS

Location: R3-2009
Speaker: Boris Semisalov, Novosibirsk State University; Sobolev Institute of Mathematics SB RAS, Novosibirsk

Abstract: For describing flows of polymer solutions and melts, we use a model that takes into account the microstructure of polymer, the induced anisotropy of flow and the external thermal and magnetic impacts. The model is based on the rheological mesoscopic approach proposed by G.V. Vinogradov and V.N. Pokrovskii. We derive the equations describing Poiseuille-type flows of a polymer fluid in the channels with rectangular, elliptical and circular cross-sections with thin inclusions which represent heating elements. We discuss the multiplicity of stationary solutions and simulate the stabilization and the loss of stability of non-stationary solutions. The results were verified by using three different numerical methods. For the case of axisymmetric flows, we obtain the exact stationary solutions and formulate a new scenario of the stability loss. The central role in mechanics of this process is played by the size and orientation of the macromolecules of the polymer fluid. Mathematical description of the process uses essentially the singular points of analytic continuation of the solution to complex plane, which are branch point singularities. The scenario is validated by comparing the obtained relations between critical values of the Reynolds and Weissenberg numbers with experimental data available in literature.

DECEMBER 4, 2:00 PM | OPTIMIZATION OF OILFIELD SERVICES TECHNOLOGIES BASED ON MATHEMATICAL MODELING AND DATA ANALYSIS 

Location: R3-2009
Speaker: Anton Morozov, PhD in Petroleum Engineering, Skoltech

Abstract: The presented work addresses the problem of low-fidelity input raw data and, as a result, low predictive capability of the machine learning model, which in turn is used to optimize the design of hydraulic fracturing. To solve the problem, an analytical filter was used based on the productivity index formulas, as well as the introduction of a numerical fracture clean-up model. As a result, the approximation quality of the machine learning model was increased from 0.609 to 0.712 by the R2 metric as well as the interpretability of the model from the physical point of view of hydraulic fracturing processes.

DECEMBER 11, 2:00 PM | MECHANICAL PROPERTIES OF 0D, 1D, 2D, 3D NANOSTRUCTURES AND COMPOSITE MATERIALS BY ATOMISTIC SIMULATIONS

Location: R3-2009
Speaker: Prof. Dmitry Kvashnin, Senior Researcher, Head of the Center for Computer Simulations of Inorganic and Composite Nanoscale Materials, Emanuel Institute of Biochemical Physics of Russian Academy of Sciences; Associate Professor of the Department of Chemical Physics of Functional Materials, MIPT

Abstract: The report presents the results of studies of the mechanical properties of nanostructures of various dimensions using quantum chemical, classical molecular dynamic methods, as well as using machine learning methods.The main effects of the influence of defects and interfaces on the mechanical properties of nanostructures will be discussed. Using of multi-level approaches for the study of nanostructures demonstrates the effectiveness and indispensability of a computer experiment in the field of physical materials science.

FEBRUARY 5, 2:00 PM | TBD

Location: R3-2009
Speaker: Faridum Jalolov, PhD student of Materials Science, Skoltech 

Abstract: TBD

FEBRUARY 12, 2:00 PM | MODELLING OF FLOWBACK IN HYDRAULICALLY FRACTURED OIL WELLS OF BAZHENOV FORMATION

Location: R3-2009
Speaker: Gleb Strizhnev, PhD student of Engineering Systems, Skoltech 

Abstract: TBD