Персона: Чмыхов, Михаил Александрович
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Институт лазерных и плазменных технологий
Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.
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Чмыхов
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Михаил Александрович
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- ПубликацияТолько метаданныеOn numerical modeling of natural convection based on the OpenFOAM solver(2020) Kozlov, V. K.; Chmykhov, M. A.; Чмыхов, Михаил Александрович© Published under licence by IOP Publishing Ltd.This work considers numerical modelling of natural incompressible convection problems in the gravity field in the Boussinesq approximation using OpenFOAM. A mathematical model of natural convection in the gravity field, using Boussinesq approximation, was considered. The built-in solver was identified and modified. The exact solution, theoretical data and experiment were used to verify the solver. A numerical study of natural convection in a horizontal liquid layer was performed. Natural convection in a fluid layer between coaxial cylinders was considered.
- ПубликацияОткрытый доступПриближенные решения краевых задач нелинейной теплопроводности(МИФИ, 2008) Чмыхов, М. А.; Чмыхов, Михаил Александрович; Кудряшов, Н. А.
- ПубликацияТолько метаданныеComparison of Some COVID-19 Data with Solutions of the SIR-model(2022) Vigdorowitsch, M.; Kudryashov, N. A.; Chmykhov, M. A.; Кудряшов, Николай Алексеевич; Чмыхов, Михаил Александрович© 2022 American Institute of Physics Inc.. All rights reserved.A classic two-parameter epidemiological SIR-model of the coronavirus propagation is considered. The first integrals of the system of non-linear equations are obtained. The Painlevé test shows that the system of equations is not integrable in the general case. Using the first integrals of the system of equations, analytical dependencies for the number of infected patients I(R) depends on recovered patients R. It is demonstrated that data on morbidity in Hubei (China), Italy, Austria, South Korea, Moscow (Russia) as well some Australian territories are satisfactorily described by the expressions obtained for I(R).
- ПубликацияТолько метаданныеAn estimative (warning) model for recognition of pandemic nature of virus infections(2023) Vigdorowitsch, M.; Kudryashov, N. A.; Chmykhov, M.; Кудряшов, Николай Алексеевич; Чмыхов, Михаил Александрович© 2021 Walter de Gruyter GmbH, Berlin/Boston 2021.A simple SIS-type mathematical model of infection expansion is presented and analysed with focus on the case SARS-Cov-2. It takes into account two processes, namely, infection and recovery/decease characterised by two parameters in total: contact rate and recovery/decease rate. Its solution has a form of a quasi-logistic function for which we have introduced an infection index that, should it become negative, can also be considered as a recovery/decease index with decrease of infected down to zero. Based on the data from open sources for the SARS-Cov-2 pandemic, seasonal influenza epidemics and a pandemic in the fauna world, a threshold value of the infection index has been shown to exist above which an infection expansion pretends to be considered as pandemic. Lean (two-parameter) SIR models affined with the warning SIS model have been built. Their general solutions have been obtained, analysed and shown to be a priori structurally adjusted to the infectives' peak in epidemiological data.
- ПубликацияОткрытый доступAnalytical features of the SIR model and their applications to COVID-19(2021) Vigdorowitsch, M.; Kudryashov, N. A.; Chmykhov, M. A.; Кудряшов, Николай Алексеевич; Чмыхов, Михаил Александрович© 2020 Elsevier Inc.A classic two-parameter epidemiological SIR-model of the coronavirus propagation is considered. The first integrals of the system of non-linear equations are obtained. The Painlevé test shows that the system of equations is not integrable in the general case. However, the general solution is obtained in quadrature as an inverse time-function. Using the first integrals of the system of equations, analytical dependencies for the number of infected patients I(t) and that of recovered patients R(t) on the number of susceptible to infection S(t) are obtained. A particular attention is paid to interrelation of I(t) and R(t) both depending on α/β, where α is the contact rate in the community and β is the intensity of recovery/decease of patients. It is demonstrated that the data on particular morbidity waves in Hubei (China), Italy, Austria, South Korea, Moscow (Russia) as well some Australian territories are satisfactorily described by the expressions obtained for I(R). The variability of parameter N having been traditionally considered as a static population size is discussed.
- ПубликацияОткрытый доступMathematical modeling of free convection problems in a gravity field in OpenFOAM(2019) Kozlov, V. K.; Chmykhov, M. A.; Чмыхов, Михаил Александрович© 2019 Published under licence by IOP Publishing Ltd.A mathematical model of natural convection in the gravity field, using Boussinesq approximation, has been presented. This model contains the continuity equation, where density variations are ignored, the Navier-Stokes equation and the equation for heat flow. Rayleigh-Benard-convection in a rectangular box, whith different types of border conditions, has been investigated. The equations solved numerically by an original solver with the use of object-oriented programming language OpenFOAM. Solver is based on PISO(Pressure-Implicit with Splitting of Operators) algorithm and finite volume method. The Prandtl number, Grashof number and Rayleigh number has been examined. Rayleigh-Benard-convection between parallel planes of different temperatures, steady convection in horizontal fluid layer and natural convection flow in a square box, enclosed by non-isothermal wall has been used for solver verification. Results have been visualized with the use of open source application ParaView.