A5058763333- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Laser-Plasma Interactions and Diagnostics
- Fluid Dynamics and Turbulent Flows
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Atomic and Molecular Physics
- Computational Fluid Dynamics and Aerodynamics
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Laser-induced spectroscopy and plasma
- Gas Dynamics and Kinetic Theory
- Astronomy and Astrophysical Research
- Ionosphere and magnetosphere dynamics
- Atmospheric Ozone and Climate
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Particle Dynamics in Fluid Flows
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Combustion and flame dynamics
- Erythrocyte Function and Pathophysiology
- Pulsars and Gravitational Waves Research
- Blood properties and coagulation
- Plasma and Flow Control in Aerodynamics
Atomic Weapons Establishment
2013-2024
University of Leeds
1997-2021
The University of Sydney
2017-2019
Lawrence Livermore National Laboratory
2017-2019
CEA DAM Île-de-France
2017-2019
Ministry of Defence
1998-2019
Keldysh Institute of Applied Mathematics
2017
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2017
University of Strathclyde
2017
Rolls-Royce (United Kingdom)
1989-2014
We describe the 2017 release of spectral synthesis code Cloudy. A major development since previous has been exporting atomic data into external files. This greatly simplifies updates and maintenance data. Many large datasets have incorporated with result that we can now predict well over an order magnitude more emission lines when all databases are fully used. The use such is not realistic for most calculations due to time memory needs, limited subset by default. Despite fact significantly...
This paper investigates the influence of different three-dimensional multi-mode initial conditions on rate growth a mixing layer initiated via Richtmyer–Meshkov instability through series well-controlled numerical experiments. Results are presented for large-eddy simulation narrowband and broadband perturbations at grid resolutions up to 3 × 10 9 points using two completely methods, comparisons made with theory experiment. It is shown that mixing-layer strongly dependent conditions, case...
This paper presents a numerical study of single-shocked turbulent mixing layer using high-order accurate implicit large-eddy simulations (ILES) for low- and high-amplitude (linear non-linear) perturbations reshocked layer. It investigates the differences in flow physics between these three cases, examining recent proposition that initial can be employed to model At early times, shocked perturbation has high levels mixing; however, at later it grows an almost identical manner low-amplitude...
Turbulent Richtmyer--Meshkov instability (RMI) is investigated through a series of high resolution three dimensional smulations two initial conditions with eight independent codes. The simulations are initialised narrowband perturbation such that growth due to non-linear coupling/backscatter from the energetic modes, thus generating lowest expected rate pure RMI. By independently assessing results each algorithm, and computing ensemble averages multiple algorithms, allow quantification key...
It has long been known that photoionization, whether by starlight or other sources, difficulty in accounting for the observed spectra of optical filaments often surround central galaxies large clusters. This paper builds on first this series which we examined heating energetic particles dissipative magnetohydrodynamic (MHD) wave can account observations. The focused molecular regions produce strong H2 and CO lines. Here extend calculations to include atomic low-ionization regions. Two major...
This paper presents a numerical study of turbulent mixing due to the interaction shock wave with an inclined material interface. The interface between two gases is modeled by geometrical random multimode perturbations represented different surface perturbation power spectra same standard deviation. Simulations Richtmyer–Meshkov instability and associated have been performed using high-resolution implicit large eddy simulations. Qualitative comparisons experimental flow visualizations are...
starbench is a project focused on benchmarking and validating different star formation stellar feedback codes. In this first paper we perform comparison study of the D-type expansion an H ii region. The aim work to understand differences observed between 12 participating numerical codes against various analytical expressions examining phase region expansion. To do this, propose two well-defined tests which are tackled by 1D 3D grid- smoothed particle hydrodynamics-based test examines 'early...
This is a summary of the 2013 release plasma simulation code Cloudy. Cloudy models ionization, chemical, and thermal state material that may be exposed to an external radiation field or other source heating, predicts observables such as emission absorption spectra. It works in terms elementary processes, so not limited any particular temperature density regime. paper summarizes advances made since last major review 1998. Much recent development has emphasized dusty molecular environments,...
The brightest galaxy in the nearby Perseus cluster, NGC 1275, is surrounded by a network of filaments. These were first observed through their Hα emission but are now known to have large molecular component with total mass approaching 1011 M⊙ gas. filaments embedded hot intracluster gas and stretch over 80 kpc. They an unusually low excitation spectrum which well modelled collisional heating ionization secondary electrons. Here we note that surface radiative flux from outer close energy...
This paper presents a numerical study of reshocked turbulent mixing layer using high-order accurate Implicit Large-Eddy-Simulations (ILES). Existing theoretical approaches are discussed, and the theory Youngs (detailed in Ref. 1) is extended to predict behaviour formed initially from shock interacting with broadband instability. The Mikaelian2 also account for molecular single-shocked prior reshock. Simulations conducted narrowband initial perturbations results growth rate decay kinetic...
Modern spectral synthesis codes need the thermally averaged free-free Gaunt factor defined over a very wide range of parameter space in order to produce an accurate prediction for spectrum emitted by ionized plasma. Until now no set data exists that would meet this fully satisfactory way. We have therefore undertaken table non-relativistic factors much wider parameters than has ever been produced before. first non-averaged factors, covering log10(epsilon_i) = -20 +10 and log10(w) -30 +25....
We present the first results from high-energy-density laboratory astrophysics experiments that explore interaction of supersonic jets/outflows with an ambient medium. Our were conducted on Omega laser facility, a large Inertial Confinement Fusion facility. In our experiments, pulse drives jet into foam. High-resolution X-ray radiography reveals resulting highly structured bow shock. These are to capture behavior both and discuss astrophysical relevance flow processes we observe in...
Abstract We discuss the application of numerical code TURMOIL to turbulent mixing in a simple spherical implosion, much simplified version an inertial confinement fusion implosion. Some form Monotone integrated large eddy simulation is required eliminate non‐physical oscillations, as shocks and contact discontinuities are present. The dissipation scheme analysed. It argued that this relatively low ‘sub‐grid’ can be precisely quantified. © British Crown Copyright 2007/MOD. Reproduced with...
We investigate consequences of the discovery that Fe II emission in quasars, one spectroscopic signatures "Eigenvector 1", may originate infalling clouds. Eigenvector 1 correlates with Eddington ratio L/L_Edd so II/Hbeta increases as increases. show "force multiplier", gas opacity to electron scattering opacity, is ~ 10^3 - 10^4 II-emitting gas. Such would be accelerated away from central object if radiation force able act on entire cloud. As had previously been deduced, infall requires...
Severe rubs between gas turbine blades and engine casings can in extreme cases result damaging blade vibration levels rapid loss of casing lining material. Even for more minor rubs, the wear material will increase tip gaps a consequent efficiency. Major rub events are extremely rare practice, there is seldom any useful diagnostic evidence root cause behaviour. Moreover, traditional analysis methods not suitable exploring wide range potential conditions under which an unstable response might...