267,519 research outputs found
Building initial models of rotating white dwarfs with SPH
A general procedure to build self-gravitational, rotating equilibrium structures with the Smoothed Particle Hydrodynamics (SPH) technique does not exist. In particular, obtaining
stable rotating configurations for white dwarf (WD) stars is
currently a major drawback of many astrophysical simulations.
Rotating WDs with low internal temperatures are connected with
both, explosive and implosive scenarios such as type Ia supernova
explosions or neutron stars formation. Simulations of these events
with SPH codes demand stable enough particle configurations as
initial models. In this work we have developed and tested a relaxation method to obtain equilibrium configurations of rotating
WDs. This method is straightforward and takes advantage of the
excellent mass and angular momentum conservation properties
of the SPH technique. Although we focus on rigid rotation and
its potential applications to several Type Ia supernova scenarios,
we also show that our proposal is also able to provide good initial
models in differential rotation, which has the potential to benefit
many other types of simulations where rotation plays a capital
role, like disk evolution and stellar formation.Peer ReviewedPostprint (published version
Variability and Evolution in Systems of Systems
In this position paper (1) we discuss two particular aspects of Systems of
Systems, i.e., variability and evolution. (2) We argue that concepts from
Product Line Engineering and Software Evolution are relevant to Systems of
Systems Engineering. (3) Conversely, concepts from Systems of Systems
Engineering can be helpful in Product Line Engineering and Software Evolution.
Hence, we argue that an exchange of concepts between the disciplines would be
beneficial.Comment: In Proceedings AiSoS 2013, arXiv:1311.319
New developments in rainâwind-induced vibrations of cables
On wet and windy days, the inclined cables of cable stayed bridges can experience large amplitude, potentially damaging oscillations known as rain-wind-induced vibration (RWIV). RWIV is believed to be the result of a complicated non-linear interaction between rivulets of rain water that run down the cables and the wind loading on the cables from the unsteady aerodynamics; however, despite a considerable international research effort, the underlying physical mechanism that governs this oscillation is still not satisfactorily understood. An international workshop on RWIV was held in April 2008, hosted at the University of Strathclyde. The main outcomes of this workshop are summarised in the paper. A numerical method to investigate aspects of the RWIV phenomenon has recently been developed by the authors, which couples an unsteady aerodynamic solver to a thin-film model based on lubrication theory for the flow of the rain water to ascertain the motion of the rivulets owing to the unsteady aerodynamic field. This novel numerical technique, which is still in the relatively early stages of development, has already provided useful information on the coupling between the external aerodynamic flow and the rivulet, and a summary of some of the key results to date is presented
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