Abstract In Smoothed Particle Hydrodynamics (SPH) methods for fluid flow, incompressibility may be imposed by a projection method with an artificial homogeneous Neumann boundary condition for the pressure Poisson equation. This is often inconsistent with physical conditions at solid walls and inflow and outflow boundaries. For this reason open-boundary flows have rarely been computed using SPH....

We study the problem of target tracking and boundary detection of a substance diffusing from a mobile source (e.g., spread of a toxic gas from a moving vehicle) using a wireless sensor network. We present a predictionbased mobility adaptive tracking (P-MAT) algorithm to study the tradeoff between energy, accuracy of tracking, coverage, and boundary estimation. P-MAT minimizes overall energy con...

A nonlinear feedback control law that achieves global asymptotic stabilization of a 2D thermal convection loop (widely known for its `Lorenz systema approximation) is presented. The loop consists of viscous Newtonian #uid contained in between two concentric cylinders standing in a vertical plane. The lower half of the loop is heated while the upper half is cooled, which makes the no-motion stea...

This paper studies optimal control problems for dynamical systems governed by neutral functional-differential inclusions that linearly depend on delayed velocity variables. Developing the method of discrete approximations, we derive new necessary optimality conditions for such problems in both EulerLagrange and Hamiltonian forms. The results obtained are expressed in terms of advanced generaliz...

In this paper we provide a sufficient condition, in terms of only one of the nine entries of the gradient tensor, i.e., the Jacobian matrix of the velocity vector field, for the global regularity of strong solutions to the three–dimensional Navier–Stokes equations in the whole space, as well as for the case of periodic boundary conditions. AMS Subject Classifications: 35Q35, 65M70

where u can be interpreted as the velocity field of an incompressible fluid motion, and p is then the associated pressure, the constant μ is the viscosity coefficient of the fluid. For simplicity, we consider homogenous Dirichlet boundary condition for the velocity, i.e. u|∂Ω = 0 and μ = 1. The conditions for the well posedness is known as inf-sup condition or Ladyzhenskaya-Babuška-Breezi (LBB)...

Step changes in air temperature(±20oC) or velocity (±0.8 and ±1.5m/s) were introduced in an air drying process, in relation to standard drying conditions of 70oC and 1.5m/s of air temperature and velocity, respectively. Compared to the standard, the variable conditions caused a clear difference of the moisture content of the dried material and the drying curves deviated significantly after the ...

Preformed Particle Gels (PPGs) treatment is one of the most promising solutions to improve conformance control in mature water flooded oil reservoirs. It is very important to be able to evaluate and predict performance of PPGs in porous media. In this paper, we will first introduce new class of enhanced PPGs designed for harsh reservoir conditions (high salinity and temperature) and then pr...

This study aimed at linear stability analysis of the stratified two-phase liquid-gas flow in a horizontal pipe. First, equations governing the linear stability of flow in each phase and boundary conditions were obtained. The governing equations were eigenvalue Orr Sommerfeld equations which are difficult and stiff problems to solve. After obtaining the velocity profiles of the gas and liquid ph...

We study the weak boundary layer phenomenon of the Navier-Stokes equations with generalized Navier friction boundary conditions, u ·n = 0, [S(u)n] tan +Au = 0, in a bounded domain in R when the viscosity, ε > 0, is small. Here, S(u) is the symmetric gradient of the velocity, u, and A is a type (1, 1) tensor on the boundary. When A = αI we obtain Navier boundary conditions, and when A is the sha...