scholarly journals NUMERICAL CALCULATION OF CONVECTIVE FLOW OF GAS AT CIRCULAR-TYPE SCHEME OF HEATING

2015 ◽  
pp. 87-93
Author(s):  
E. M. Sorokina ◽  
A. G. Obukhov
Keyword(s):  
Convective Flow ◽  
Stokes Equations ◽  
Complete System ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Heat Conducting ◽  
Boundary Condi Tions ◽  
Navier Stokes Equations ◽  
Viscous Heat ◽  
Condi Tions

To investigate the convective flows of polytropic gas a complete system of Navier - Stokes equations is consid-ered. As the initial and boundary conditions the specific ratios are offered. The proposed initial and boundary condi-tions realization is carried out at construction of the numerical solution of the complete system of Navier - Stokes equations for modeling the unsteady state three-dimensional convection flows of the compressible viscous heat-conducting gas in the isolated cubic area. Three components of the velocity vector are calculated for the initial stage of the convective flow. It is shown that the velocity components are complex and depend essentially on the heating shape, height and time.

scholarly journals THREE-DIMENSIONAL INSTANTANEOUS STREAMLINESOF GAS FLOWS FOR SIMULATION THE STEADY-STATE OUTPUT OF AN ARTIFICIAL TORNADO

2018 ◽  
pp. 71-76
Author(s):  
R. E. Volkov ◽  
A. G. Obukhov
Keyword(s):  
Steady State ◽  
Stokes Equations ◽  
Complete System ◽  
Three Dimensional ◽  
Unsteady Flows ◽  
Navier Stokes ◽  
Gas Flows ◽  
Heat Conducting ◽  
Navier Stokes Equations ◽  
Coriolis Forces

The method of parallelizing a numerical solution of the complete system of Navier - Stokes equations is used to describe three-dimensional unsteady flows of a viscous compressible heat-conducting gas in ascending swirling flows. In this case the action of gravity and Coriolis forces is taken into account, and the coefficients of viscosity and thermal conductivity are assumed to be constant. The results of the numerical construction of instantaneous streamlines characterizing complex three-dimensional flows are presented for simulation the steady-state output of an ascend-ing swirling air flow in an artificial tornado.

scholarly journals PARALLEL COMPUTATIONS IN STUDIES OF DEPENDENCE OF GAS DYNAMIC PARAMETERS OF UPWARD SWIRLING FLOW OF GAS ON BLOWING VELOCITY

2016 ◽  
pp. 92-97
Author(s):  
R. E. Volkov ◽  
A. G. Obukhov
Keyword(s):  
Stokes Equations ◽  
Swirling Flow ◽  
Initial Conditions ◽  
Exact Analytical Solution ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Heat Conducting ◽  
Computational Domain ◽  
Navier Stokes Equations ◽  
Gas Dynamic

The rectangular parallelepiped explicit difference schemes for the numerical solution of the complete built system of Navier-Stokes equations. These solutions describe the three-dimensional flow of a compressible viscous heat-conducting gas in a rising swirling flows, provided the forces of gravity and Coriolis. This assumes constancy of the coefficient of viscosity and thermal conductivity. The initial conditions are the features that are the exact analytical solution of the complete Navier-Stokes equations. Propose specific boundary conditions under which the upward flow of gas is modeled by blowing through the square hole in the upper surface of the computational domain. A variant of parallelization algorithm for calculating gas dynamic and energy characteristics. The results of calculations of gasdynamic parameters dependency on the speed of the vertical blowing by the time the flow of a steady state flow.

On the formation of weak plane shock waves by impulsive motion of a piston

1966 ◽  
Vol 25 (4) ◽  
pp. 705-718 ◽  
Author(s):  
John P. Moran ◽  
S. F. Shen
Keyword(s):  
Large Time ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Plane Shock ◽  
Heat Conducting ◽  
Piston Problem ◽  
Navier Stokes Equations ◽  
Viscous Heat ◽  
Equation Boundary ◽  
Weak Plane

The piston problem for a viscous heat-conducting gas is studied under the assumption that the piston Mach number ε is small. The linearized Navier–Stokes equations are found to be valid up to times of the order of ε−2mean free times after the piston is set in motion, while at large times the solution is governed by Burgers's equation. Boundary conditions for the large-time solution are supplied by the matching principle of the method of inner and outer expansions, which is also used to construct a composite solution valid both for small and for large times.

scholarly journals METHOD OF PARALLELIZATION OF NUMERICAL ALGORITHMOF NAVIER-STOKES EQUATIONS COMPLETE SYSTEM

2016 ◽  
pp. 92-98
Author(s):  
R. E. Volkov ◽  
A. G. Obukhov
Keyword(s):  
Thermal Conductivity ◽  
Gas Flow ◽  
Stokes Equations ◽  
Swirling Flow ◽  
Three Dimensional ◽  
Computation Time ◽  
Navier Stokes ◽  
Heat Conducting ◽  
Navier Stokes Equations ◽  
Comparison Of The Results

The article considers the features of numerical construction of solutions of the Navier-Stokes equations full system describing a three-dimensional flow of compressible viscous heat-conducting gas under the action of gravity and Coriolis forces. It is shown that accounting of dissipative properties of viscosity and thermal conductivity of the moving continuum, even with constant coefficients of viscosity and thermal conductivity, as well as the use of explicit difference scheme calculation imposes significant restrictions on numerical experiments aimed at studying the arising complex flows of gas or liquid. First of all, it is associated with a signifi- cant complication of the system of equations, the restrictions on the value of the calculated steps in space and time, increasing the total computation time. One of the options is proposed of algorithm parallelization of numerical solution of the complete Navier - Stokes equations system in the vertical spatial coordinate. This parallelization option can significantly increase the computing performance and reduce the overall time of counting. A comparison of the results of calculation of one of options of gas flow in the upward swirling flow obtained by serial and parallel programs is presented.

scholarly journals Decay rate of generalized solutions for equations of a viscous heat-conducting gas

2021 ◽  
Author(s):  
Zhilei Liang
Keyword(s):  
Large Time ◽  
Stokes Equations ◽  
Large Time Behavior ◽  
Ideal Gas ◽  
Generalized Solutions ◽  
Navier Stokes ◽  
Heat Conducting ◽  
Time Behavior ◽  
Navier Stokes Equations ◽  
Viscous Heat

The large time behavior is considered for the solutions of the Navier-Stokes equations for one-dimensional viscous polytropic ideal gas in unbounded domains. Using the local anti-derivatives functions technique, we obtain the power type decay estimates for the generalized solutions as time goes to infinity

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