unsteady hydromagnetic generalised couette flow of a viscous, incompressible and electrically conducting fluid between two horizontal parallel porous plates darcian channel in the presence of a uniform transverse magnetic field taking hall current and ion-slip into account in a rotating system is investigated. an exact solution of the governing equations is obtained by laplace transform techniq...

A general formula for the second-order projection method combined with the level set method is developed to simulate unsteady, incompressible multifluid flow with phase change. A subcell conception is introduced in a modified mass transfer model to accurately calculate the mass transfer across the interface. The third-order essentially nonoscillatory (ENO) scheme and second-order semi-implicit ...

Low Reynolds number aerodynamics is important for various applications including micro-aerial vehicles, sailplanes, leading edge control devices, high-altitude unmanned vehicles, wind turbines and propellers. These flows are generally characterized by the presence of laminar separation bubbles. These bubbles are generally unsteady and have a significant effect on the overall resulting aerodynam...

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...

SIMPLE-type methods are presented in a more concise formulation. This formulation is used to analyze temporal accuracy for unsteady flows. Detailed error formulations are given. Analysis shows that SIMPLE-type methods have second-order temporal accuracy if a second-order temporal updating technique is employed to update both the convective and diffusion terms. Two algorithms for unsteady flows ...

We evaluate the applicability of a production computational fluid dynamics code for conducting detached eddy simulation for unsteady flows. A second-order accurate Navier-Stokes code developed at NASA Langley Research Center, known as TLNS3D, is used for these simulations. We focus our attention on high Reynolds number flow (Re = 5× 10 − 1.4× 10) past a circular cylinder to simulate flows with ...

This paper presents a parallel Newton-Krylov-Schwarz method for the numerical simulation of unsteady flows at high Reynolds number around a high-speed train under crosswind. With a realistic train geometry, a realistic Reynolds number, and a realistic wind speed, this is a very challenging computational problem. Because of the limited parallel scalability, commercial CFD software is not suitabl...

This paper presents new, efficient methods for computing finite-time Lyapunov exponent (FTLE) fields in unsteady flows. The methods approximate the particle flow map to eliminate redundant particle integrations in neighboring flow map calculations. Two classes of flow map approximations are investigated based on composition of intermediate flow maps; unidirectional approximation constructs a ti...

ANSYS-CFX is an effective and multipurpose software which can be used for simulation the computational fluid dynamics (CFD) solutions at all levels of complexity. This software can be used for numerical solution of two and three dimensional flows, compressible and incompressible flows, viscous and non-viscous flows, laminar and turbulent flows, Newtonian and non-Newtonian flows, porous media, s...

Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Methods based on vector field topology are known for their convenience for visualizing and analysing steady flows, but a counterpart for unsteady flows is still missing. However, a lot of good and relevant work aiming at such a solution is available. We give an overvie...