solving a large sparse set of linear equations is of the problems widely seen in every numerical investigation in the entire range of engineering disciplines. employing a finite element approach in solving partial derivative equations, the resulting stiffness matrices would contain many zero-valued elements. moreover, storing all these sparse matrices in a computer memory would slower the compu...

This paper presents a strategy using a high fidelity delayed-detached-eddy simulation (DDES) to simulate 3-D fluid-structural interaction for predicting AGARD Wing 445.6 flutter boundary in a transonic flow. A dual-time step implicit unfactored Gauss-Seidel iteration with Roe scheme are employed for the flow solver. The special numerical techniques used herein include: a 5th order WENO scheme f...

The aim of this work is to derive a well-balanced numerical scheme to approximate the solutions of the Euler equations with a gravitational potential. This system admits an infinity of steady state solutions which are not all known in an explicit way. Among all these solutions, the hydrostatic atmosphere has a special physical interest. We develop an approximate Riemann solver using the formali...

in this research, the effect of surface roughness and bubble injection on skin friction and hydrodynamic drag force has been numerically considered. this research is based on taylor-couette flow. considered flow includes two concentric cylinders which internal cylinder is movable and external is immovable. the effective equations on the flow includes: equations of momentum, continuous, turbulen...

In this paper, we consider the classical wave equation with time-dependent, spatially multiscale coefficients. We propose a fully discrete computational method in spirit of localized orthogonal decomposition space backward Euler scheme time. show optimal convergence rates and time beyond assumptions spatial periodicity or scale separation Further, an adaptive update strategy for time-dependent ...

We present a relaxation system for ideal MHD that is an extension of the Suliciu relaxation system for the Euler equations of gas dynamics. From it one can derive approximate Riemann solvers with three or seven waves, that generalize the HLLC solver for gas dynamics. Under some subcharacteristic conditions, the solvers satisfy discrete entropy inequalities, and preserve positivity of density an...

This paper investigates the axial unsteady flow of a generalized Burgers’ fluid with fractional constitutive equation in a circular micro-tube, in presence of a time-dependent pressure gradient and an electric field parallel to flow direction and a magnetic field perpendicular on the flow direction. The mathematical model used in this work is based on a time-nonlocal constitutive equation for s...

The animation of delicate vortical structures gas and liquids has been great interest in computer graphics. However, common velocity-based fluid solvers can damp the flow, while vorticity-based suffer from performance drawbacks. We propose a new solver derived reformulated Euler equation using covectors. Our method generates rich vortex dynamics by an advection process that respects Kelvin circ...