929 research outputs found

    Vanishing Viscous Limits for 3D Navier-Stokes Equations with A Navier-Slip Boundary Condition

    Full text link
    In this paper, we investigate the vanishing viscosity limit for solutions to the Navier-Stokes equations with a Navier slip boundary condition on general compact and smooth domains in R3\mathbf{R}^3. We first obtain the higher order regularity estimates for the solutions to Prandtl's equation boundary layers. Furthermore, we prove that the strong solution to Navier-Stokes equations converges to the Eulerian one in C([0,T];H1(Ω))C([0,T];H^1(\Omega)) and L^\infty((0,T)\times\o), where TT is independent of the viscosity, provided that initial velocity is regular enough. Furthermore, rates of convergence are obtained also.Comment: 45page

    On the regularity up to the boundary for certain nonlinear elliptic systems

    Get PDF
    We consider a class of nonlinear elliptic systems and we prove regularity up to the boundary for second order derivatives. In the proof we trace carefully the dependence on the various parameters of the problem, in order to establish, in a further work, results for more general systems

    A posteriori error estimates for the virtual element method

    Get PDF
    An a posteriori error analysis for the virtual element method (VEM) applied to general elliptic problems is presented. The resulting error estimator is of residual-type and applies on very general polygonal/polyhedral meshes. The estimator is fully computable as it relies only on quantities available from the VEM solution, namely its degrees of freedom and element-wise polynomial projection. Upper and lower bounds of the error estimator with respect to the VEM approximation error are proven. The error estimator is used to drive adaptive mesh refinement in a number of test problems. Mesh adaptation is particularly simple to implement since elements with consecutive co-planar edges/faces are allowed and, therefore, locally adapted meshes do not require any local mesh post-processing

    Caracterização dos sistemas de produção da agricultura familiar de Paragominas-PA: a pecuária e propostas de desenvolvimento.

    Get PDF
    Caracterização da região de estudo. Diagnóstico. Caracterização dos sistemas agrícolas.bitstream/item/57599/1/Oriental-Doc5.pd
    corecore