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991.
992.
A new phenomenological mathematical model of the propagation of high- and low-salinity solutions through inhomogeneous aquifers is proposed. The model consists of interrelated equations of two-phase flow and diffusive mass transfer through a porous medium in a region with a traveling boundary. Features of different contamination scenarios of are analyzed with reference to particular examples. 相似文献
993.
994.
Disappearance of interfaces in finite time 总被引:2,自引:0,他引:2
For the solution of filtration equation with a density which is decreasing at infinity fast enough we found that the interface disappears in finite time.
Sommario Si considera un problema di filtrazione con densità che decresce all'infinito in modo sufficientemente rapido. Si dimostra che il contorno libero sparisce in tempo finito.相似文献
995.
A general formulation of the plane coupled dynamical and aerodynamical problem of the motion of a rigid body with a rotational degree of freedom in a viscous incompressible fluid flow is given. A computation technique for solving the Navier-Stokes equations based on the meshless viscous vortex domain method is used. The autorotation of a single plate and a pair of plates is investigated. The effect of the reduced moment of inertia and the Reynolds number on the angular rotation velocity is determined. The time dependences of the hydrodynamic loads are compared with the corresponding instantaneous flow patterns. The increased the autorotation velocity of two plates in tandem is detected. 相似文献
996.
Jong Uhn Kim 《Journal of Differential Equations》2006,220(1):163-194
In this paper, we discuss an initial-boundary value problem and a Cauchy problem for the stochastic porous medium equation. Our basic estimates are based on the known results due to (Math. Sbornik 67 (1965) 609-642, Arch. Rational Mech. Anal. 25 (1967) 64-80). By the procedure developed in (Trans. Amer. Math. Soc. 354 (2001) 1117-1135), we obtain solutions over the given probability space rather than martingale solutions. We will also establish the existence of invariant measures when the space domain is bounded. 相似文献
997.
A. T. Ismail-Zadeh A. I. Korotkii I. A. Tsepelev 《Computational Mathematics and Mathematical Physics》2006,46(12):2176-2186
Inverse (time-reverse) simulation of three-dimensional thermoconvective flows is considered for a highly viscous incompressible fluid with temperature-dependent density and viscosity. The model of the fluid dynamics is described by the Stokes equations, the incompressibility and heat balance equations subject to the appropriate initial and boundary conditions. To solve the problem backward in time, the quasi-reversibility method is applied to the heat balance equation. The numerical solution is based on the introduction of a two-component vector potential for the velocity of the medium, on the application of the finite element method with a special tricubic spline basis for computing this potential, and on the application of the splitting method and the method of characteristics for computing the temperature. The numerical algorithm is designed to be executed on parallel computers. The proposed numerical algorithm is used to reconstruct the evolution of diapiric structures in the Earth’s upper mantle. The computational efficiency of the algorithm is analyzed on the basis of the appropriate functionals of residuals. 相似文献
998.
G. V. Filatov 《International Applied Mechanics》2006,42(3):331-335
A new optimization model is proposed to design corrosion-affected structures with limited life. The optimization problem is
stated as a nonlinear-programming problem. The mass of the structure is minimized. The design is considered optimal when physical
wear and obsolescence arrive simultaneously. A smooth cylindrical shell compressed in the longitudinal direction is used to
illustrate the model
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 3, pp. 97–101, March 2006. 相似文献
999.
Joachim Naumann 《Mathematical Methods in the Applied Sciences》2006,29(16):1883-1906
This paper is concerned with the equations of non‐stationary motion in 3D of heat‐conducting incompressible viscous fluids with temperature‐dependent viscosity. The conservation of internal energy includes the usual dissipation term. We prove the existence of a ‘weak solution with defect measure’ to the system of PDEs under consideration. Our method of proof is based on a regularization of the equations of conservation of momentum. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
1000.
This paper is devoted to the mathematical analysis of the miscible displacement of a set of radionuclides in a flow occurring in a heterogeneous porous medium. The flow is governed by Darcy's law, and the motion of the chemical species is given by a nonclassical advection-diffusion-reaction equations system. The novelty of the model lies in the adsorption phenomenon that leads to a time derivative of a nonlinear term in these equations. A semi-discretization method is used to establish the existence of weak solutions to this system. Uniform L∞-estimates on the solutions are specified. 相似文献