Shumei Lou, Guoqun Zhao and Rui Wang
The paper aims to use the finite volume method widely used in computational fluid dynamics to avoid the serious remeshing and mesh distortion during aluminium profile extrusion…
Abstract
Purpose
The paper aims to use the finite volume method widely used in computational fluid dynamics to avoid the serious remeshing and mesh distortion during aluminium profile extrusion processes simulation when using the finite element method. Block-structured grids are used to fit the complex domain of the extrusion. A finite volume method (FVM) model for aluminium extrusion numerical simulation using non-orthogonal structured grids was established.
Design/methodology/approach
The influences of the elements ' nonorthogonality on the governing equations discretization of the metal flow in aluminium extrusion processes were fully considered to ensure the simulation accuracy. Volume-of-fluid (VOF) scheme was used to catch the free surface of the unsteady flow. Rigid slip boundary condition was applied on non-orthogonal grids.
Findings
This paper involved a simulation of a typical aluminium extrusion process by the FVM scheme. By comparing the simulation by the FVM model established in this paper with the ones simulated by the finite element method (FEM) software Deform-3D and the corresponding experiments, the correctness and efficiency of the FVM model for aluminium alloy profile extrusion processes in this paper was proved.
Originality/value
This paper uses the FVM widely used in CFD to calculate the aluminium profile extrusion processes avoiding the remeshing and mesh distortion during aluminium profile extrusion processes simulation when using the finite element method. Block-structured grids with the advantage of simple data structure, small storage and high numerical efficiency are used to fit the complex domain of the extrusion.
Details
Keywords
Shumei Lou, Guoqun Zhao, Rui Wang and Xianghong Wu
The purpose of this paper is to find an efficient way by using finite volume method (FVM) to simulate the aluminum alloy profile extrusion processes.
Abstract
Purpose
The purpose of this paper is to find an efficient way by using finite volume method (FVM) to simulate the aluminum alloy profile extrusion processes.
Design/methodology/approach
By assuming isotropic conditions, the hot aluminum material is described as a non‐linear Newtonian fluid material. Semi‐implicit method for pressure‐linked equations algorithm is used to calculate the physical fields, and the dynamic viscosity is updated then. Volume of fluid method and moving grid method are also used for unsteady flow to catch the free surface of the material and the moving bound.
Findings
FVM model in this paper is an accurate and efficient method for the numerical simulation of aluminum profile extrusion processes. Compared with finite element method software, FVM model is both memory and CPU efficient.
Practical implications
Provide theoretical reference for sound extrusion process and die designs, which are the key factors to produce desirable products in industrial production.
Originality/value
The paper finds an efficient way to introduce the FVM in computational fluid dynamics field into the simulation of the steady and unsteady aluminum alloy profile extrusion processes. It provides a reference for people who are interested in FVM and extrusion processes.
Details
Keywords
Fan Yu, Junping Qiu and Wen Lou
This paper aims to solve the disadvantages of content-based domain ontology (CBDO) and metadata-based domain ontology (MDO) and improve organization and discovery efficiency of…
Abstract
Purpose
This paper aims to solve the disadvantages of content-based domain ontology (CBDO) and metadata-based domain ontology (MDO) and improve organization and discovery efficiency of library resources by resource ontology (RO).
Design/methodology/approach
The paper constructed an RO model. Methods of informetrics are utilized to reveal semantic relationships among library resources. Methods of ontology, ontology-relational database mapping (O-R mapping) and relational database modelling are utilized to construct RO. Take author co-occurrence for example, the paper demonstrated the capability of RO model.
Findings
RO not only revealed the deep-level semantic relationships of metadata of library resources but also realized totally computer-automated processing. RO improved the efficiency of knowledge organization and discovery.
Research limitations/implications
Semantic relationships revealed by RO are limited to simple metadata, which makes it difficult to reveal fine-grained semantic relationships. Ongoing research focuses on the revelation of semantic relationships based on the title and abstract.
Practical implications
The paper includes implications for utilizing methods of Informetrics to construct ontology.
Originality/value
This paper proposed a standardized process of ontology construction in library resources. It may be of potential interest for anyone who needs to effectively organize library resources.