We develop a quasi-two-level, coarse-mesh-free characteristic nonoverlapping domain decomposition method for unsteady-state convection-diffusion partial differential equations in multidimensional spaces. The development of the domain decomposition method is carried out by utilizing an additive Schwarz domain decomposition preconditioner, by using an Eulerian-Lagrangian method for convection-dif...

A mechanism for fast magnetic reconnection in collisionless plasma is studied for understanding sawtooth collapse in tokamak discharges using a two-fluid model for cold ions and electrons. Explosive growth of the tearing mode enabled by electron inertia is analytically estimated using an energy principle with a nonlinear displacement map. Decrease in the potential energy in the nonlinear regime...

Effect of altitude is discussed in the unsteady separation of multi stage rockets. Axisymmetric, unsteady and turbulent Navier stokes equations are solved numerically. The governing equations are split into a hyperbolic inviscid part and a parabolic diffusion part. The hyperbolic part is solved by an explicit second-order time and space of Godunov-type scheme. Moving mesh and moving boundary al...

Problems of propagation and diffraction nonstationary waves in elastic bodies are great theoretical practical importance such fields science technology as aircraft construction, shipbuilding, seismic exploration minerals, resistance structures, many others. The paper considers the problem skew-symmetric unsteady shear from a thick-walled spherical shell space. To solve problem, integral Laplace...

Particle deposition on a square cylinder placed in a rectangular channel was investigated for unsteady vortical  ows. For the two-phase  ow simulations, the unsteady gas  ow Ž eld was computed by solving the incompressible Navier-Stokes equations using a staggered-grid control volume approach and the Marker-andCell (MAC) technique. The particle dynamics were simulated using themodiŽ edBasset...

In this work, an unsteady state analysis of the compression cycle of a small hermetic reciprocating compressor for domestic refrigeration was carried out. The mass and energy balances were applied to the refrigerant inside the cylinder in order to determine the mass and temperature behaviour through the compression process. A specific onedimensional model of the valves was developed to calculat...

Crossflow-dominated swept-wing boundary layers are known to undergo a highly nonlinear transition process. In low-disturbance environments, the primary instability of these flows consists mainly of stationary streamwise vortices that modify the mean velocity field and hence the stability characteristics of the boundary layer. The result is amplitude saturation of the dominant stationary mode an...

Foam flooding (or injection of foam) is a common technology to enhance oil recovery. Although the effects of permeability on foam flooding were well studied in many laboratory experiments, little research has been focused on the specificity of low permeability. In this paper, a series of constant-quality nitrogen foam flow experiments were conducted to investigate the effects of permeability on...

We recall the PFS (Pressurized and Free Surface) model constructed for the modeling of unsteady mixed flows in closed water pipes where transition points between the free surface and pressurized flow are treated as a free boundary associated to a discontinuity of the gradient of pressure. Then we present a numerical kinetic scheme for the computations of unsteady mixed flows in closed water pip...