Bonyah, E. Juga, M. L. Matsebula, L. M. Chukwu, C. W.
Published in
Mathematical Models and Computer Simulations

The coronavirus disease (COVID-19) pandemic has caused more harm than expected in developed and developing countries. In this work, a fractional stochastic model of COVID-19 which takes into account the random nature of the spread of disease, is formulated and analyzed. The existence and uniqueness of solutions were established using the fixed-poin...

Amanbaev, T. R. Antony, S. J.
Published in
Mathematical Models and Computer Simulations

The effect of the isolation of individuals in the population on the dynamics of the epidemic is analyzed. Based on the SIR model, a SIRDi model is built that takes into account the isolation of individuals, as well as the presence of deceased patients, which is appropriate to use in cases of widespread infection, when the number of infected is comp...

Ladonkina, M. E. Nekliudova, O. A. Tishkin, V. F.
Published in
Mathematical Models and Computer Simulations

Abstract—Numerical modeling of a supersonic flow around solids is challenging due to the possibility of the nonphysical instabilities that can affect the solution. In this paper, we propose a new hybrid numerical flux for calculating the fluxes of the Euler part of the system of the Navier-Stokes equations, which avoids the occurrence of instabilit...

Nesterova, I. S. Gerke, K. M.
Published in
Mathematical Models and Computer Simulations

AbstractConventional oil and gas reservoirs used for hydrocarbon production are partially depleted, and the global energy market is eyeing new unconventional energy sources. According to some estimates, shale gas resources in the world amount to 200 trillion m3, but only a small part is recoverable reserves in terms of modern technology. A detailed...

Gavrikov, M. B. Taiurskii, A. A.
Published in
Mathematical Models and Computer Simulations

AbstractThe mathematical theory of powerful tornadoes in atmospheric air, in which the angular velocity of the rotation of air masses in the vortex ring of the parent cloud that generates the tornado is much greater than the angular velocity of the rotation of the air flow on the Earth’s surface, is constructed. The theory developed is relevant for...

Zlotnik, A. A. Lomonosov, T. A.
Published in
Mathematical Models and Computer Simulations

Abstract—Explicit two-level difference schemes on staggered meshes are studied for two well-known regularizations of 1D barotropic gas dynamics equations, including schemes with discretization in x with the property of total energy dissipation. The criteria for L2-dissipativity in the Cauchy problem are derived for their linearizations on a constan...

Shirokov, I. A.
Published in
Mathematical Models and Computer Simulations

AbstractAn original algorithm for constructing a computational grid for modeling an external gas-dynamic flow around an axisymmetric model using a TetGen mesh generator is described. The algorithm gives opportunity to construct unstructured tetrahedral meshes in space around the model in such a way that the cells near the surface have a shape close...

Yuditskaya, A. S. Tkachev, S. S.
Published in
Mathematical Models and Computer Simulations

AbstractThe correct modeling of the gravitational field of small celestial bodies is an urgent problem in solving the problems of approaching, landing on, and researching these bodies. There are a number of different methods for describing the gravitational field, each of which has its own advantages and disadvantages. This paper considers and pres...

Kurtc, V. V. Anufriev, I. E. Trufanov, D. O.
Published in
Mathematical Models and Computer Simulations

AbstractThe microscopic car-following model with explicit reaction-time delay and several predecessors in interaction is presented. This model is based on the well-known optimal velocity approach. Multi-anticipation and human reaction time allow for the capturing of natural drivers’ behavior when identifying their longitudinal acceleration. The tra...

Galanin, M. P. Rodin, A. S.
Published in
Mathematical Models and Computer Simulations

AbstractThe problem of the contact interaction of the elements of the barrel of an electromagnetic accelerator is solved. A two-dimensional elastic approximation is used. The computational domain is a quarter of the cross-section and includes a rail, insulator, and load-bearing shell. To solve the problem, the two-level additive Schwarz method is u...