arXiv subjects

H. Lian

Publications and source records attributed to H. Lian.

3 recordsLinked to original sources

arXiv2026

Self-organized hybrid scenario mediated by fishbone modes in the EAST tokamak

Self-organized hybrid scenario mediated by fishbone modes in the Experimental Advanced Superconducting Tokamak (EAST) is reported in this work. In this regime, internal transport barriers(ITBs) and a flat core safety factor profile were maintained simultaneously by fishbone modes. First,the drive of low-frequency flows by fishbone modes is clarified, which subsequently suppresses turbulence transport. Besides, fishbone-induced poloidally symmetric (m = 0) toroidal current sheets were first reported experimentally, which drive outward current redistribution that mitigates core current peaking. Together, these effects enable hybrid operation with stable ITBs and robust magnetohydrodynamic (MHD) stability, revealing a self-organized pathway for sustaining hybrid scenario for fusion reactors.

physics.plasm-ph↗

arXiv2013

An Isogeometric Boundary Element Method for elastostatic analysis: 2D implementation aspects

The concept of isogeometric analysis, whereby the parametric func- tions that are used to describe CAD geometry are also used to approx- imate the unknown fields in a numerical discretisation, has progressed rapidly in recent years. This paper advances the field further by outlin- ing an isogeometric Boundary Element Method (IGABEM) that only re- quires a representation of the geometry of the domain for analysis, fitting neatly with the boundary representation provided completely by CAD. The method circumvents the requirement to generate a boundary mesh representing a significant step in reducing the gap between engineering design and analysis. The current paper focuses on implementation details of 2D IGABEM for elastostatic analysis with particular attention paid towards the differences over conventional boundary element implementa- tions. Examples of Matlab R° code are given whenever possible to aid understanding of the techniques used.

math.NA↗

arXiv2012

Recent Developments in CAD/analysis Integration

For linear elastic problems, it is well-known that mesh generation dominates the total analysis time. Different types of methods have been proposed to directly or indirectly alleviate this burden associated with mesh generation. We review in this paper a subset of such methods centred on tighter coupling between computer aided design (CAD) and analysis (finite element or boundary element methods). We focus specifically on frameworks which rely on constructing a discretisation directly from the functions used to describe the geometry of the object in CAD. Examples include B-spline subdivision surfaces, isogeometric analysis, NURBS-enhanced FEM and parametric-based implicit boundary definitions. We review recent advances in these methods and compare them to other paradigms which also aim at alleviating the burden of mesh generation in computational mechanics.

math.NA↗