2 citations · 4 across the 10 of their papers we have counts for
11 papers
A Finite Element Method for the Grad--Mercier Equation
Ben Ashby, Tristan Pryer
We develop and analyse a conforming piecewise affine finite element method for the Grad--Mercier equation, a nonlocal elliptic model for magnetic equilibria whose source depends on…
Diffusion Synthetic Acceleration for polytopic discretisations of Boltzmann transport
Ansar Calloo, Matthew Evans, François Madiot +1
We present a computational study of diffusion synthetic acceleration (DSA) for the monoenergetic, isotropically scattering transport equations, discretised in space by a poly…
Characteristic Sweeps and Source Iteration for Charged-Particle Transport with Continuous Slowing-Down and Angular Scattering
Ben S. Ashby, Alex Lukyanov, Tristan Pryer
We develop a semi-analytic deterministic framework for charged-particle transport with continuous slowing-down in energy and angular scattering. Directed transport and energy advec…
A finite element method for a non-Newtonian dilute polymer fluid
Ben S. Ashby, Gabriel R. Barrenechea, Alex Lukyanov +2
We study the discretisation of a uniaxial (rank-one) reduction of the Oldroyd-B model for dilute polymer solutions, in which the conformation tensor is represented as $\sig = \vec…
Modelling and Analysis of Non-Contacting Mechanical Face Seals with Axial Disturbances and Misalignment
Ben S Ashby, Tristan Pryer, Nicola Y Bailey
Advancements in industrial applications are driving developments in non-contacting mechanical seal technology. Key requirements include improvements in efficiency and reliability,…
A Positivity-Preserving Finite Element Framework for Accurate Dose Computation in Proton Therapy
Ben S. Ashby, Abdalaziz Hamdan, Tristan Pryer
We present a stabilised finite element method for modelling proton transport in tissue, incorporating both inelastic energy loss and elastic angular scattering. A key innovation is…
A nodally bound-preserving finite element method for hyperbolic convection-reaction problems
Ben S. Ashby, Abdalaziz Hamdan, Tristan Pryer
In this article, we present a numerical approach to ensure the preservation of physical bounds on the solutions to linear and nonlinear hyperbolic convection-reaction problems at t…
Duality based error control for the Signorini problem
Ben S. Ashby, Tristan Pryer
In this paper we study the a posteriori bounds for a conforming piecewise linear finite element approximation of the Signorini problem. We prove new rigorous a posteriori estimates…
Discretisation of an Oldroyd-B viscoelastic fluid flow using a Lie derivative formulation
Ben S. Ashby, Tristan Pryer
In this article we present a numerical method for the Stokes flow of an Oldroyd-B fluid. The viscoelastic stress evolves according to a constitutive law formulated in terms of the…
Adaptive modelling of variably saturated seepage problems
Ben Ashby, Cassiano Bortolozo, Alex Lukyanov +1
In this article we present a goal-oriented adaptive finite element method for a class of subsurface flow problems in porous media, which exhibit seepage faces. We focus on a repres…
Nonlinear solution techniques for solving a Monge-Ampère equation for redistribution of a mesh
P. A. Browne, J. Prettyman, H. Weller +2
A Monge-Ampère (MA) equation arises when seeking an optimally transported mesh that equidistributes a given monitor function in Cartesian space. This MA equation is a fully nonline…