Global Existence of Heat-Conductive Incompressible Viscous Fluids

In this paper, we consider the Cauchy problem of non-stationary motion of heat-conducting incompressible viscous fluids in \(\mathbb{R}^{2}\), where the viscosity and heat-conductivity coefficient vary with the temperature. It is shown that the Cauchy problem has a unique global-in-time strong solution \((u, \theta)(x,t)\) on \(\mathbb{R}^{2}\times(0,\infty)\), provided the initial norm \(\|\nabla u_{0}\|_{L^{2}}\) is suitably small, or the lower-bound of the coefficient of heat conductivity (i.e. \(\underline{\kappa}\)) is large enough, or the derivative of viscosity (i.e. \(|\mu'(\theta)|\)) is small enough.     

The Strong Solution for the Viscous Polytropic Fluids with Non-Newtonian Potential

The authors study an initial boundary value problem for the three-dimensional Navier-Stokes equations of viscous heat-conductive fluids with non-Newtonian potential in a bounded smooth domain. They prove the existence of unique local strong solutions for all initial data satisfying some compatibility conditions. The difficult of this type model is mainly that the equations are coupled with elliptic, parabolic and hyperbolic, and the vacuum of density causes also much trouble, that is, the initial density need not be positive and may vanish in an open set.     

Strong Solutions to Non-stationary Channel Flows of Heat-Conducting Viscous Incompressible Fluids with Dissipative Heating

We study an initial-boundary-value problem for time-dependent flows of heat-conducting viscous incompressible fluids in channel-like domains on a time interval (0,T). For the parabolic system with strong nonlinearities and including the artificial (the so called “do nothing”) boundary conditions, we prove the local in time existence, global uniqueness and smoothness of the solution on a time interval (0,T ^∗), where 0<T ^∗≤T.     

Density-Dependent Incompressible Fluids with Non-Newtonian Viscosity

We study the system of PDEs describing unsteady flows of incompressible fluids with variable density and non-constant viscosity. Indeed, one considers a stress tensor being a nonlinear function of the symmetric velocity gradient, verifying the properties of p-coercivity and (p–1)-growth, for a given parameter p > 1. The existence of Dirichlet weak solutions was obtained in [2], in the cases p 12/5 if d = 3 or p 2 if d = 2, d being the dimension of the domain. In this paper, with help of some new estimates (which lead to point-wise convergence of the velocity gradient), we obtain the existence of space-periodic weak solutions for all p 2. In addition, we obtain regularity properties of weak solutions whenever p 20/9 (if d = 3) or p 2 (if d = 2). Further, some extensions of these results to more general stress tensors or to Dirichlet boundary conditions (with a Newtonian tensor large enough) are obtained.     

粘性系数依赖于密度的Korteweg型不可压流体的强解问题

研究一类Korteweg型不可压流体模型的强解问题.针对粘性系数依赖于密度的情形,当初始值满足兼容性条件(9)对,证明了强解的局部存在性和唯一性.我们在这指出,本文允许初始真空存在.     

A Blow-up Criterion of Strong Solutions to the Compressible Viscous Heat-Conductive Flows with Zero Heat Conductivity

We study the compressible Navier-Stokes equations of viscous heat-conductive fluids in a periodic domain \mathbbT³\mathbb{T}^{3} with zero heat conductivity k=0. We prove a blow-up criterion for the local strong solutions in terms of the temperature and positive density, similar to the Beale-Kato-Majda criterion for ideal incompressible flows.     

一类三维不可压非牛顿流的轨道吸引子

讨论了一类自治不可压非牛顿流方程组在三维有界区域上解的轨道渐近行为,证明了该类方程组在适当的拓扑空间中存在轨道吸引子.     

一类带有非牛顿位势的可压缩Navier-Stokes方程整体强解的存在性

主要研究了一类带有非牛顿位势的可压缩Navier-Stokes方程:其中粘性系数μ依赖于密度ρ,Φ是非牛顿位势.证明了上述问题的强解的存在性.在相容性条件下,得到了强解的唯一性.     

Global Regularity of 3D Nonhomogeneous Incompressible Micropolar Fluids

This paper is concerned with the global well-posedness of strong and classical solutions for the 3D nonhomogeneous incompressible micropolar equations with vacuum. We prove that the problem (1.1)–(1.5) has a unique global strong/classical solution \((\rho,u,w)\), provided \(\mu_{1}\) is sufficiently large, or \(\|\rho_{0}\|_{L^{\infty}}\) or \(\|\rho_{0}^{1/2}u_{0}\| ^{2}_{L^{2}}+\|\rho_{0}^{1/2}w_{0}\|^{2}_{L^{2}}\) is small enough.

     

非牛顿粘性不可压流方程的近似惯性流形

本文利用对非牛顿粘性不可压缩流方程对时间 t的解析性和长时间渐近性估计 ,具体构造了它的近似惯性流形 ,并得出收敛阶估计 .     

The Incompressible Limits of Viscous Polytropic Fluids with Zero Thermal Conductivity Coefficient

ABSTRACT

We study the singular limit of viscous polytropic fluids without thermal conductivity as the Mach number tends to zero. A uniform existence result for the Cauchy problem in R ³ is proved under the assumption that the initial data belongs uniformly to H ^k (R ³) with k = 2, 3 and is well-prepared in H ¹ (R ³).     

The Existence Of Nonhomogeneous,Viscous And Incompressible Flow In Unbounded Domains

The existence of global (in time) solution {ρu,p} (density, velocity field and pressure) of a partial differential problem modelling the behaviour of a viscous, nonhomogenous and incompressible flow has been recently obtained viscous, nonhomogenous and incompressible flow has been recently obtained by J. Simon. In his most general result, he finds a solution which satifies an initial condition in an appropriate weak sense. In this paper, we present an extension of this result to the case of arbitrary unbounded three–dimensional fluid domains.

1. Introduction.

2. The main result.

3. Some technical Lemmas.

4. Proof of Theorem 1.

4.1 The existence and properties of {ρR, U^R PR}

4.2 Some estimates for ρR,U^R and their time derivatives.

4.3 Further estimates.

4.4 The choice of a convergent sequence and conclusions.

References.     

具有强吸收的非Newtonian扩散方程的行波解及交界面

本文我们首先找到了有限行波解,然后研究了具有强吸收项的非Newtonian扩散方程交界面的短时间行为. 我们将表明交界面的短时间行为依赖于初始浓度, 准确的说,找到了初始浓度的一个临界值,用它可区分交界面是热前面还是冷前面.     

非牛顿流体管内不定常流的解析解

本文用积分变换方法分别给出了二阶流体和Maxwell流体管内不定常流运动方程的解析解.据此可以分析轴向速度和切应力分布与变化特征,为管道工程设计提供理论依据.     

Global Weak Solutions for the Cauchy Problem to One-Dimensional Heat-Conductive MHD Equations of Viscous Non-resistive Gas

We investigate the dynamics of the Vlasov-Poisson system in the presence of radiation damping. A propagation result for velocity moments of order \(k>3\) is established in (Kunze and Rendall in Ann. Henri Poincaré 2:857–886, 2001). In this paper, we prove existence of global solutions propagating velocity and velocity-spatial moments of order \(k>2\) and establish an explicit polynomially growing in time bound on the moments.

     

一类非牛顿系统弱解的长时间性态

本文讨论一类非牛顿系统弱解的长时间性态,证明解在L2 范数下的衰减速率为(1 t)-n/4 达到和线性热方程一致.     

Double Potential Method for Modeling the Internal Flow of a Viscous Incompressible Liquid

Doklady Mathematics - The problem of numerical modelling water purification from iron impurities is considered. The cleaning task is relevant for many industrial applications, including the...     

等熵可压Navier-Stokes-Poisson方程局部强解适定性

该文得到了三维情形等熵可压Navier-Stokes-Poisson方程局部强解的存在性、唯一性及稳定性. 重要的是,该文允许初始密度真空的存在. 首先用推广形式的Gronwall不等式得到了强解的局部存在性,然后得到了较弱条件下的唯一性,在证明唯一性的同时得到了稳定性.