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## On properties of aggregated regularized systems of equations for a homogeneous multicomponent gas mixture

Mathematical Methods in the Applied Sciences. 2022. Vol. 45. No. 15. P. 8906-8927.

Two aggregated regularized systems of equations for a multicomponent homogeneous gas mixture are considered.

An entropy balance equation with a non-negative entropy production is derived for them in the presence of diffusion fluxes. The existence, uniqueness and $L^2$-dissipativity of weak solutions to an initial-boundary value problem for the systems linearized on a constant solution are established. The Petrovskii parabolicity and the local in time classical unique solvability of the Cauchy problem are also proved for the aggregated systems themselves.

Zlotnik A.A., Fedchenko A.S., Doklady Mathematics 2021 Vol. 104 No. 3 P. 340-346

For an aggregated quasi-gasdynamic system of equations for a homogeneous gas mixture, we give an entropy balance equation with a nonnegative entropy production in the presence of diffusion fluxes. We also derive the existence, uniqueness, and L^2 -dissipativity of weak solutions to an initial-boundary value problem for the system linearized at a constant solution. Additionally, the Petrovskii parabolicity ...

Added: February 17, 2022

Zlotnik A.A., Fedchenko A.S., Differential Equations 2022 Vol. 58 No. 3 P. 341-356

We study a quasihydrodynamic system of equations for a homogeneous (with common velocity and temperature) multicomponent gas mixture in the absence of chemical reactions with a common regularizing velocity. For this system, we derive an entropy balance equation with nonnegative entropy production in the presence of diffusion flows of the mixture components. In the absence of diffusion ...

Added: May 13, 2022

Zlotnik A.A., Computational Mathematics and Mathematical Physics 2012 Vol. 52 No. 7 P. 1060-1071

For the quasi-gasdynamic system of equations, there holds the law of nondecreasing entropy. Difference methods based on this system have been successfully used in numerous applications and test gasdynamic computations. In theoretical terms, however, for standard spatial discretizations of this system, the nondecreasing entropy law does not hold exactly even in the one-dimensional case because ...

Added: February 4, 2013

Elizarova T., Zlotnik A., AIP Conference Proceedings 2020 Vol. 2293 No. 1 P. 210016-1-210016-4

We consider binary gas mixture flows with viscous compressible components in the absence of chemical reactions.
We aggregate the previously derived regularized equations for inhomogeneous mixtures and thus derive new simpler regularized equations for homogeneous ones (i.e., with the common velocity and temperature). The entropy balance equation with the non-negative entropy production is stated for the new equations. They ...

Added: July 21, 2019

Zlotnik A., Lomonosov T., Математическое моделирование 2021 Т. 33 № 5 С. 16-34

We study explicit two-level finite-difference schemes on staggered meshes for two known regularizations of 1D barotropic gas dynamics equations including schemes with discretizations in x that possess the dissipativity property with respect to the total energy. We derive criterions of L^2-dissipativity in the Cauchy problem for their linearizations at a constant solution with zero background ...

Added: April 1, 2021

Chetverushkin B. N., Zlotnik A.A., Russian Journal of Mathematical Physics 2017 Vol. 24 No. 3 P. 299-309

We study a multidimensional hyperbolic quasi-gasdynamic (HQGD) system of equations containing terms with a regularizing parameter $\tau>0$ and 2nd order space and time derivatives; the body force is taken into account. We transform it to the form close to the compressible Navier-Stokes system of equations. Then we derive the entropy balance equation and show that ...

Added: July 19, 2017

Zlotnik A., Symmetry 2021 Vol. 13 No. 11 Article 2184

We deal with 2D and 3D barotropic gas dynamics system of equations with two viscous regularizations: so-called quasi-gas dynamics (QGD) and quasi-hydrodynamics (QHD) ones. The system is linearized on a constant solution with any velocity, and an explicit two-level in time and symmetric three-point in each spatial direction finite-difference scheme on the uniform rectangular mesh is ...

Added: November 12, 2021

Zlotnik A. A., Chetverushkin B. N., Doklady Mathematics 2017 Vol. 95 No. 3 P. 276-281

Entropy balance in the one-dimensional hyperbolic quasi-gasdynamic (HQGD) system of equations is analyzed. In regular flow regimes, it is shown that the behavior of entropy in the HQGD system is determined by terms involving the natural viscosity and thermal conductivity coefficients. The total entropy production differs from the Navier–Stokes equations for viscous compressible heat-conducting gases ...

Added: April 25, 2017

Zlotnik Alexander, Discrete and Continuous Dynamical Systems - Series B 2022

We study an explicit two-level in time and symmetric in space finite-difference scheme for a linearized 2D and 3D gas dynamic system of equations with a kinetic-type regularization. For an initial-boundary value problem on any nonuniform rectangular mesh, sufficient Courant-type conditions for the $L^2$-dissipativity are derived for the first time by the energy method. For the Cauchy ...

Added: June 20, 2022

Zlotnik A.A., Lomonosov T.A., Mathematical Models and Computer Simulations 2021 Vol. 13 No. 6 P. 1097-1108

Explicit two-level difference schemes on staggered meshes are studied for two well-known
regularizations of 1D barotropic gas dynamics equtions, including schemes with discretization in
x with the property of total energy dissipation. The criteria of L^2-dissipativity in the Cauchy problem
are derived for their linearizations on a constant solution with zero background velocity. The criteria for
schemes on nonstaggered and staggered ...

Added: September 21, 2021

Zlotnik A., Lomonosov T., Applied Mathematics Letters 2020 Vol. 103 Article 106198

We study an explicit in time and symmetric in space finite-difference scheme with a kinetic regularization for the 2D and 3D gas dynamics system of equations linearized at a constant solution (with any velocity). We derive both necessary and sufficient conditions for $L^2$-dissipativity of the Cauchy problem for the scheme by the spectral method. The Courant number ...

Added: December 21, 2019

Елизарова Т. Г., Zlotnik A., Четверушкин Б. Н., Доклады Академии наук 2014 Т. 459 № 4 С. 395-399

Квазигазодинамический (КГД) подход, позволяющий строить удобные и надежные разностные схемы для численного решения разнообразных задач газовой динамики, к настоящему времени представлен в нескольких монографиях. В одной из них на основе кинетического уравнения Больцмана в форме, применимой для смеси одноатомных газов, была выведена и апробирована КГД система уравнений бинарных смесей нереагирующих совершенных политропных газов. ...

Added: August 27, 2014

Zlotnik A., Applied Mathematics Letters 2019 Vol. 92 P. 115-120

We deal with an explicit finite-difference scheme with a regularization for the 1D gas dynamics equations linearized at the constant solution. The sufficient condition on the Courant number for the $L^2$-dissipativity of the scheme is derived in the case of the Cauchy problem and a non-uniform spatial mesh. The energy-type technique is developed to this end, and ...

Added: January 20, 2019

A. A. Zlotnik, T. A. Lomonosov, Computational Mathematics and Mathematical Physics (Germany) 2022 Vol. 62 No. 11 P. 1817-1837

We study an explicit two-level finite difference scheme on staggered meshes, with a quasi-hydrodynamic regularization, for 1D barotropic gas dynamics equations. We derive both necessary conditions and sufficient conditions close to them, for $L^2$-dissipativity of solutions to the Cauchy problem linearized on a constant solution, for any background Mach number $M$. We apply the spectral approach and analyze matrix ...

Added: October 18, 2022

Злотник А.А., Доклады Академии наук 2010 Т. 431 № 5 С. 605-609

Квазигазодинамическая (КГД) система уравнений была предложена Б.Н. Четверушкиным и Т.Г. Елизаровой и затем модифицировалась Т.Г. Елизаровой и Ю.В. Шеретовым. Она рассматривалась только с уравнениями состояния совершенного политропного газа. В работе предложено ее обобщение на случай общих уравнений состояния, связанных равенством Максвелла и удовлетворяющих условиям термодинамической устойчивости. Для КГД системы с общими уравнениями состояния выведен закон ...

Added: December 22, 2015

Furmanov K. K., Nikol'skii I. M., Computational Mathematics and Modeling 2016 Vol. 27 No. 2 P. 247-253

Added: December 22, 2016

Sirotin V., Arkhipova M., Dubrova T. A. et al., Bielsko-Biala : University of Bielsko-Biala Press, 2016

The main attributes of modern enterprises should be the flexibility and the ability of forecasting the future. Constant adaptation to the changing environment and the rapidity of undertaking certain actions which are conditioned by specific situations determine the rules for the future position of market competition. Effective and efficient adjustment of the company in line ...

Added: November 2, 2016

Litvin Y. V., Абрамов И. В., Технологии техносферной безопасности 2016 № 66

Advanced approach to the assessment of a random time of arrival fire fighting calculation on the object of protection, the time of their employment and the free combustion. There is some quantitative assessments with the review of analytical methods and simulation ...

Added: August 27, 2016

Maslov V., Теоретическая и математическая физика 2019 Т. 201 № 1 С. 65-83

We study the process of a nucleon separating from an atomic nucleus from the mathematical standpoint
using experimental values of the binding energy for the nucleus of the given substance. A nucleon becomes
a boson at the instant of separating from a fermionic nucleus. We study the further transformations of
boson and fermion states of separation in a ...

Added: November 1, 2019

Buchstaber V., Limonchenko I., Embeddings of moment-angle manifolds and sequences of Massey products / Cornell University. Series math "arxiv.org". 2018. No. 1808.08851.

We introduce the notions of algebraic and geometric direct families of polytopes and develop a theory of such families. The theory is then applied to the problem of existence of nontrivial higher Massey products in cohomology of moment-angle-complexes. ...

Added: September 29, 2019

Pahomov F., Известия РАН. Серия математическая 2016 Т. 80 № 6 С. 173-216

Полимодальная логика доказуемости
GLP была введена Г. К. Джапаридзе в 1986 г. Она является логикой доказуемости для ряда цепочек предикатов доказуемости возрастающей силы. Всякой полимодальной логике соответствует многообразие полимодальных алгебр. Л. Д. Беклемишевым и А. Виссером был поставлен вопрос о разрешимости элементарной теории свободной GLP-алгебры, порожденной константами 0, 1 [1]. В этой статье для любого натурального n решается аналогичный вопрос для логик GLPn, являющихся ...

Added: December 4, 2017

Arzhantsev I., Journal of Lie Theory 2000 Vol. 10 No. 2 P. 345-357

Added: July 8, 2014

Min Namkung, Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1-16915-18

Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...

Added: November 16, 2020

Decrouez G. G., Hall P., Bernoulli: a journal of mathematical statistics and probability 2013 Vol. 19 No. 4 P. 1268-1293

Motivated by a problem arising when analysing data from quarantine searches, we explore properties of distributions of sums of independent means of independent lattice-valued random variables. The aim is to determine the extent to which approximations to those sums require continuity corrections. We show that, in cases where there are only two different means, the ...

Added: September 29, 2014