We propose two enhancements of quasi-Newton methods used to accelerate coupling iterations for partitioned fluid-structure interaction. Quasi-Newton have been established as flexible, yet robust, efficient and accurate multi-physics simulations in general. The library preCICE provides several variants, the so-called IQN-ILS method being most commonly used. It uses input output differences coupl...

This paper investigates the synchronization of two Newton-Leipnik Chaotic Systems. A new sufficient condition of global asymptotic synchronization is attained from the theory of stability of time-varying systems. In addition , compared with the previously proposed method , the sufficient condition for the synchronization of two linearly coupled unified chaotic systems is simpler and less conser...

Flame sheet problems are on the natural route to the numerical solution of detailed chemistry, laminar di usion ames, which, in turn, are important in many engineering applications. In order to model the ame structure more accurately, we use the vorticity-velocity formulation of the uid ow equations instead of the more traditional stream function-vorticity approach. The numerical solution of th...

The cosmic X-ray background (XRB) is largely due to accretion onto supermassive black holes integrated over cosmic time. Thus, extragalactic X-ray surveys offer the potential to contribute substantially to our understanding of the physics of Active Galactic Nuclei (AGN) as well as the evolution of the AGN population. Such surveys have dramatically advanced over the past four years, largely due ...

The dynamics of rigid bodies coupled by holonomic and non-holonomic constraints are formulated by the Newton Euler method employing a compact notation. The compact notation involves the use of two three by three matrices A and B and the totality of constraint vector C. The Lagrangian and Newton Euler methods are related for a one link rigid body in order to introduce the methodology of the pape...

The cosmic X-ray background (XRB) is largely due to accretion onto supermassive black holes integrated over cosmic time. Thus, extragalactic X-ray surveys offer the potential to contribute substantially to our understanding of the physics of Active Galactic Nuclei (AGN) as well as the evolution of the AGN population. Such surveys have dramatically advanced over the past four years, largely due ...

A parallel, fully coupled, nonlinearly implicit Newton-Krylov-Schwarz algorithm is proposed for the numerical simulation of a magnetic reconnection problem described by a system of resistive Hall magnetohydrodynamics equations in slab symmetry. A key component of the algorithm is a restricted additive Schwarz preconditioner defined for problems with doubly periodic boundary conditions. We show ...

This paper presents an overlapped block-parallel Newton method for solving large nonlinear systems. The graph partitioning algorithms are first used to partition the Jacobian into weakly coupled overlapping blocks. Then the simplified Newton iteration is directly performed, with the diagonal blocks and the overlapping solutions assembled in a weighted average way at each iteration. In the algor...

The application of Krylov subspace iterative methods to unsteady three-dimensional Navier–Stokes codes on massively parallel and distributed computing environments is investigated. Previously, the Euler mode of the Navier–Stokes flow solver Transonic Unsteady Rotor Navier–Stokes (TURNS) has been coupled with a Newton–Krylov scheme which uses two Conjugate-Gradient-like (CG) iterative methods. F...