Prefacedoi: 10.1088/1742-6596/1666/1/011001pmid: N/A
The present volume of the Journal of Physics: Conference Series represents contributions from participants of the IX International conference «Lavrentyev readings on mathematics, mechanics, and physics» dedicated to the 120th anniversary of birth of Academician Mikhail Alekseevich Lavrentyev. The Conference was held at Novosibirsk Akademgorodok, Russia, on September 07–11, 2020, and organized by Lavrentyev Institute of Hydrodynamics and Novosibirsk State University.The Conference is traditional and attracts attention of mathematicians and physicists. Scientific activities of the Conference include discussion of a wide range of problems: mathematical problems of continuum mechanics, physics and mechanics of high-energy processes, fluid mechanics and mechanics of solids. The program of conference included 12 plenary presentations (40 minutes) and 186 oral presentations (20 minutes) given by more than 170 participants from 38 cities of Russia (Moscow, Saint-Petersburg, Novosibirsk, Vladivostok, Tomsk, Yakutsk, Perm, Novokuznetsk, Biysk, Barnaul, Krasnoyarsk, etc.). A significant part of talks (about 30 %) were presented by young researchers and postgraduate students.We would like to thank the Speakers for their significant contributions to the conference. We also would like to thank the members of the Organizing Committee. We cannot end without expressing our many thanks to our sponsors (Russian Foundation for Basic Research (grant number 20-01-22014), Novosibirsk State University, Mathematical Center in Akademgorodok (the agreement with Ministry of Science and High Education of the Russian Federation number 075-15-2019-1675) for their financial support.Novosibirsk, September 2020Evgeny ErmanyukEvgeny RudoyEduard Pruuel
Peer review declarationdoi: 10.1088/1742-6596/1666/1/011002pmid: N/A
All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.□Type of peer review: Single-blind / Double-blind / Triple-blind / Open / Other (please describe) Single-blind□Conference submission management system: Conference website, official conference e-mail [email protected]□□Number of submissions received: 82□Number of submissions sent for review: 78□Number of submissions accepted:74□Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100):90%□Average number of reviews per paper: 2□Total number of reviewers involved:24□Any additional info on review process: Single-blind peer reviews were conducted by 2 referees (chair of the corresponding section and one reviewer). The main condition for the papers’ publication was also an oral presentation at the conference. A group of technical proofreaders checked all papers for grammar/spelling, style and other journal publishing requirements.□□Contact person for queries: Elena Fominykh, Lavrentyev Institute of Hydrodynamics of the Siberian Branch of the Russian Academy of Sciences, [email protected]□
Optimization in designing heat flux concentratorsAlekseev, Gennady; Tereshko, Dmitry
doi: 10.1088/1742-6596/1666/1/012001pmid: N/A
Inverse problems for a 2D heat conduction model connected with developing technologies of designing thermal concentrators are considered. The shells are assumed consisting of a finite number of sectors every of which is filled with homogeneous isotropic medium. By optimization method these problems are reduced to finite-dimensional extremum problems for the solution of which the particle swarm optimization is used. Rigorous optimization analysis shows that concentrators designed using optimization method have the highest efficiency in the class of devices under consideration and are easy for implementation.
Mathematical and physical modeling shape memory polymer compositesAnnin, B D; Karpov, E V; Moskvichev, E V; Yu Larichkin, A
doi: 10.1088/1742-6596/1666/1/012002pmid: N/A
In the article the influence of fiber orientation on the deformation character of specimens from composites with shape memory (EMC) under transverse and longitudinal bending is studied. Also, restoration of the initial configuration of the sample upon activation of the shape memory effect (SME) is considered. The effect of fiber orientation on the formation of systems of irreversible structural defects during molding is revealed. The degree of shape restoration upon SME implementation and the reproducibility of the original form upon repetition of the shape fixing-recovering cycles depend on these defects. Variants of a material model with linear hardening and a Voigt model for describing the shape memory effect in modeling the stages of molding and restoration are considered.
The load exerted on a rigid wall by a highly porous cylinder during impactBelov, G V; Markov, V A; Popov, Yu V; Pusev, V I; Selivanov, V V; Frolov, V V
doi: 10.1088/1742-6596/1666/1/012006pmid: N/A
The paper shows the directions to improve the assessment of the external load on a rigid structure during the crash of an aircraft. Our estimates describe the modeling of initial stage of impact (deformation of the nose compartment). The main goal is to evaluate the correctness and applicability of the Riera approach to mechanical equivalent of onboard equipment. Volume-perforated samples of the aluminum alloy D16T were used as mechanical equivalents in numerical and experimental studies. Both our model which uses constitutive equations of high-porous elastoplastic medium (Carroll-Holt model) and direct 3D modeling of the structure of volume-perforated samples by finite element method in the LS-DYNA allows us to obtain the history of load on a rigid wall. We demonstrate the features and differences between this approaches and the Riera approach.
MHD model of an incompressible polymeric fluid. Linear instability of the resting stateBlokhin, Alexander; Tkachev, Dmitry
doi: 10.1088/1742-6596/1666/1/012007pmid: N/A
We study the linear stability of a resting state for a generalization of the basic rheological Pokrovski-Vinogradov model for flows of solutions and melts of an incompressible viscoelastic polymeric medium to the nonisothermal case under the influence of magnetic field. We prove that the corresponding linearized problem describing magnetohydrodynamic flows of polymers in an infinite plane channel has the following property: for certain values of the conduction current which is given on the electrodes, i.e. on the channel boundaries, the problem has solutions whose amplitude grows exponentially (in the class of functions periodic along the channel).
Hydrodynamics of new high-speed surface systemsBoyko, A V; Golub, A P; Yeroshin, V A; Samsonov, V A
doi: 10.1088/1742-6596/1666/1/012008pmid: N/A
Until recently, high-speed surface vessels consisted mainly of hydrogliders, airfoil boats, hydrofoil and air-cushion craft. Their hydrodynamic characteristics are well understood and the vessels involved have high speeds and excellent sailing qualities. In recent years, however, there has been some expansion of this group of vessels by means of high-speed surface objects on wheels (baggies) and tracks (snowmobiles), in some cases at speeds far exceeding those of hydrofoil and air-cushion craft. Information on the hydrodynamic characteristics of these vessels is not available in the literature. This prompts us to study their hydrodynamic parameters and to consider the practical use of these vessels. The report describes conditions for water rolling of wheeled and tracked systems with grousers, simulates this phenomenon, derives the dependence of draft and bearing capacity of wheeled systems on the Froude number, and presents the dependence of tracked traction on the dimensionless parameter equal to the ratio of absolute speeds of the lower part of a track and the above-water part of a model.