Large Data Existence Result for Unsteady Flows of Inhomogeneous Shear-Thickening Heat-Conducting Incompressible Fluids

We consider unsteady flows of inhomogeneous, incompressible, shear-thickening and heat-conducting fluids where the viscosity depends on the density, the temperature and the shear rate, and the heat conductivity depends on the temperature and the density. For any values of initial total mass and initial total energy we establish the long-time existence of weak solution to internal flows inside an arbitrary bounded domain with Lipschitz boundary.     

Global large solutions to 3-D inhomogeneous Navier–Stokes system with one slow variable

Under a nonlinear smallness condition on the isotropic critical Besov norm to the fluctuation of the initial density and the critical anisotropic Besov norm of the horizontal components of the initial velocity, which have to be exponentially small compared with the critical anisotropic Besov norm to the third component of the initial velocity, we investigate the global wellposedness of 3-D inhomogeneous incompressible Navier–Stokes equations (1.2) in the critical Besov spaces. The novelty of this results is that the isotropic space structure to the inhomogeneity of the initial density function is consistent with the propagation of anisotropic regularity for the velocity field. In the second part, we apply the same idea to prove the global wellposedness of (1.2) with some large data which are slowly varying in one direction.     

A note on regularity and uniqueness of natural convection with effects of viscous dissipation in 3D open channels

We prove the existence of unique regular solutions of steady-state buoyancy-driven flows of viscous incompressible heat-conducting fluids in 3D open channels under mixed boundary conditions. The model takes into account the phenomena of the viscous energy dissipation.     

On the stationary flows of viscous,incompressible and heat-conducting fluids

We consider a boundary-value problem describing the motion of viscous, incompressible and heat-conducting fluids in a bounded domain in ?³. We admit non-homogeneous boundary conditions, the appearance of exterior forces and heat sources. Our aim is to prove the existence of a solution of the problem in Sobolev spaces.     

Continuous dependence and uniqueness for heat-conducting viscous fluids in bounded domains

Continuous dependence upon the initial data for solutions to initial-boundary value problems in bounded domains is investigated in connection with heat-conducting viscous fluids with hidden variables. It turns out that, in the case of incompressible fluids, the initial-boundary conditions guaranteeing the continuous dependence of classical solutions on the initial data, the body force, and the heat supply are the most natural generalization of the usual ones. Indeed, the boundary data for the hidden variables are the strict counterpart of those for the stress tensor and the heat supply in the standard theory.     

Stability and bifurcation in viscous incompressible fluids

We consider heat-conducting viscous incompressible (not necessarily Newtonian) fluids under the general Stokesian constitutive hypotheses. Given a natural and mild condition on the stress tensor at vanishing velocity, which is satisfied for Newtonian fluids, we discuss the stability behavior of stationary states at which the fluid is at rest and at constant temperature. In particular, we prove the existence of global small strong solutions for rather general isothermal non-Newtonian fluids. We also study bifurcation problems and show that subcritical bifurcations can occur. This effect can be seen only if the full energy equation is taken into consideration, that is, if the energy dissipation term is not dropped, as is done in the usual Boussinesq approximation. Bibliography: 29 titles. Published inZapiski Nauchnykh Seminarov POMI, Vol. 233, 1996, pp. 9–29.     

A coherent analysis of Stokes flows under boundary conditions of friction type

This paper is concerned with the stationary and nonstationary flow of viscous incompressible fluid under boundary conditions of friction type, which are certain nonlinear boundary conditions similar to the so-called Signorini boundary condition in elasticity. We assume that the flow is governed by the linear Stokes equation, while the boundary condition is nonlinear. From the methodological viewpoint, the analysis is carried out in a coherent way, starting from study of the related boundary value problems for the stationary flow by means of the theory of variational inequalities, and getting to wellposedness of the initial boundary value problems for the nonstationary flow by means of the nonlinear semigroup theory. From the viewpoint of applications, we mention original motivations and include some new generalizations like the cases of anisotropic friction and inhomogeneous boundary value.     

Zero Mach number limit in critical spaces for compressible Navier-Stokes equations

We are concerned with the existence and uniqueness of local or global solutions for slightly compressible viscous fluids in the whole space. In [6] and [7], we proved local and global well-posedness results for initial data in critical spaces very close to the one used by H. Fujita and T. Kato for incompressible flows (see [14]). In the present paper, we address the question of convergence to the incompressible model (for ill-prepared initial data) when the Mach number goes to zero. When the initial data are small in a critical space, we get global existence and convergence. For large initial data and a bit of additional regularity, the slightly compressible solution is shown to exist as long as the corresponding incompressible solution does. As a corollary, we get global existence (and uniqueness) for slightly compressible two-dimensional fluids.     

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.     

On the Navier–Stokes flows for heat-conducting fluids with mixed boundary conditions

We consider a coupled model for steady flows of viscous incompressible heat-conducting fluids with temperature dependent material coefficients in a fixed three-dimensional open cylindrical channel. We introduce the Banach spaces X and Y to be the space of possible solutions of this problem and the space of its data, respectively. We show that the corresponding operator of the problem acting between X and Y is Fréchet differentiable. Applying the local diffeomorphism theorem we get the local solvability results for a variational formulation.     

Global existence of two phase nonhomogeneous viscous incompbessible fluid flow

We shall discuss the temporarily global solution for the two phase free boundary problem. Both fluids are regarded as immiscible, nonhomogeneous, viscous and incompressible and subject to surface tention on the interface. The global solution is obtained near the equilibrium state under the sufficiently small initial data and external forces.     

Global existence of strong solution for the Cucker–Smale–Navier–Stokes system

We present a global existence theory for strong solution to the Cucker–Smale–Navier–Stokes system in a periodic domain, when initial data is sufficiently small. To model interactions between flocking particles and an incompressible viscous fluid, we couple the kinetic Cucker–Smale model and the incompressible Navier–Stokes system using a drag force mechanism that is responsible for the global flocking between particles and fluids. We also revisit the emergence of time-asymptotic flocking via new functionals measuring local variances of particles and fluid around their local averages and the distance between local averages velocities. We show that the particle and fluid velocities are asymptotically aligned to the common velocity, when the viscosity of the incompressible fluid is sufficiently large compared to the sup-norm of the particles' local mass density.     

Wellposedness for anisotropic rotating fluid equations

The wellposedness problem for an anisotropic incompressible viscous fluid in R3,rotating around a vector B(t,x):=(b1(t,x),b2(t,x),b3(t,x)),is studied.The global wellposedness in the homogeneous case (B...     

Large global solutions to 3-D inhomogeneous Navier-Stokes equations slowly varying in one variable

Motivated by Chemin and Gallagher (2010) [8], we consider the global wellposedness to the 3-D incompressible inhomogeneous Navier-Stokes equations with large initial velocity slowly varying in one space variable. In particular, we proved that when the initial density is close enough to a positive constant, then given divergence free initial velocity field of the type , as that in Chemin and Gallagher (2010) [8] for the classical Navier-Stokes system, we shall prove the global wellposedness of (INS) for ? sufficiently small. The main difficulty here lies in the fact that we will have to obtain the L¹(R⁺;Lip(R³)) estimate for convection velocity in the transport equation of (INS). Toward this and due to the strong anisotropic properties of the approximate solutions, we will have to work in the framework of anisotropic type Besov spaces here.     

Asymptotic stability of Oseen vortices for a density-dependent incompressible viscous fluid

In the analysis of the long-time behavior of two-dimensional incompressible viscous fluids, Oseen vortices play a major role as attractors of any homogeneous solution with integrable initial vorticity [T. Gallay, C.E. Wayne, Global stability of vortex solutions of the two-dimensional Navier–Stokes equation, Commun. Math. Phys. 255 (1) (2005) 97–129]. As a first step in the study of the density-dependent case, the present paper establishes the asymptotic stability of Oseen vortices for slightly inhomogeneous fluids with respect to localized perturbations.     

Identification problem for a stationary magnetohydrodynamic model of a viscous heat-conducting fluid

An identification problem for the stationary magnetohydrodynamic (MHD) equations governing a viscous heat-conducting fluid with inhomogeneous boundary conditions for the velocity, electromagnetic field, and temperature is stated and analyzed. The solvability of the problem is proved, an optimality system is derived, and sufficient conditions on the initial data are established that ensure the uniqueness and stability of the solution.     

关于一个具切边粘性实际粘性热传导流体的注记

This paper is concerned with the global existence and exponential stability of solutions with large initial date in H1 for real viscous heat-conducting flow with shear viscosity.     

Local solvability of equations of magnetohydrodynamics on the whole space

Using the technique of expanding domains, we prove the existence of a weak, local in time solution to the equations of magnetohydrodynamics, derived from the equations for viscous, compressible and heat-conducting fluids, on the whole space under special assumptions on pressure and entropy. Compared with the same approach for barotropic compressible fluids, we show how to overcome loss of the global integrability of temperature and velocity fields in corresponding spaces.     

The Incompressible Navier-Stokes Equations in Vacuum

We are concerned with the existence and uniqueness issue for the inhomogeneous incompressible Navier-Stokes equations supplemented with H¹ initial velocity and only bounded nonnegative density. In contrast to all the previous works on those topics, we do not require regularity or a positive lower bound for the initial density or compatibility conditions for the initial velocity and still obtain unique solutions. Those solutions are global in the two-dimensional case for general data, and in the three-dimensional case if the velocity satisfies a suitable scaling-invariant smallness condition. As a straightforward application, we provide a complete answer to Lions' question in his 1996 book Mathematical Topics in Fluid Mechanics, vol. 1, Incompressible Models, concerning the evolution of a drop of incompressible viscous fluid in the vacuum. © 2018 Wiley Periodicals, Inc.     

On quasi-stationary models of mixtures of compressible fluids

We consider mixtures of compressible viscous fluids consisting of two miscible species. In contrast to the theory of non-homogeneous incompressible fluids where one has only one velocity field, here we have two densities and two velocity fields assigned to each species of the fluid. We obtain global classical solutions for quasi-stationary Stokes-like system with interaction term. This work was supported by SFB 611.