On the simulation of the Newtonian fluid Extrudate Swell using a moving mesh finite volume interface tracking method

The extrudate swell, the geometrical modifications that take place when the flowing material leaves a confined flow inside a channel and moves freely without the restrictions promoted by the walls, is a relevant phenomenon in several polymer processing techniques. For instance, in profile extrusion, the extrudate cross-section is subjected to a number of distortions motivated by the swell, which are very difficult to anticipate, especially for complex geometries. As happens in many industrial processes, numerical modelling might provide useful information to support design tasks, i.e., to allow identifying the cross section geometry which produces the desired profile, after the changes promoted by the extrudate swell. In this work we study the capability of an open-source moving mesh finite volume interface tracking solver, to simulate the extrudate swell process in profile extrusion. For this purpose, the data provided by Mitsoulis et al. (E. Mitsoulis, G.C. Georgiou, and Z. Kountouriotis. A study of various factors affecting Newtonian extrudate swell. Computers & Fluids, 57:195{207, 2012) on the simulation of the extrudate swell flow of a Newtonian fluid at different Reynolds number, is considered as the reference for validation. The results obtained with the OpenFOAM solver show a very good agreement with the reference data.NORTE-07-0162-FEDER-000086 and the Minho Advanced Computing Center (MACC) for providing HPC. CPCA_A00_6057202

Validation of a moving mesh finite volume interface tracking method through the numerical simulation of the Newtonian extrudate swell

The geometrical modifications that take place when the flowing material leaves a confined flow inside a channel and moves freely without the restrictions promoted by the walls, commonly designated by extrudate swell, is a relevant phenomenon in several polymer processing techniques. For instance, in profile extrusion, the extrudate cross-section is subjected to a number of distortions motivated by the swell, which are very difficult to anticipate, especially for complex geometries. To circumvent those problems numerical modelling might provide useful information to support design tasks, i.e., to allow identifying the cross section geometry which produces the desired profile, after the changes promoted by the extrudate swell. In this work we employed an open-source moving mesh finite volume interface tracking solver to simulate the extrudate swell process in profile extrusion. The data provided by Mitsoulis et al. (E. Mitsoulis, G.C. Georgiou, and Z. Kountouriotis. A study of various factors affecting Newtonian extrudate swell. Computers & Fluids, 57:195{207, 2012) on the simulation of the extrudate swell flow of a Newtonian fluid at different Reynolds number is considered as the reference for validation. The results obtained with the OpenFOAM solver show a very good agreement with the reference dataCPCA_A00_60572020. NORTE-07-0162-FEDER-000086 and the Minho Advanced Computing Center (MACC) for providing HPC resources that contributed to the research results reported within this abstrac

Implementation of integral viscoelastic constitutive models in OpenFOAM® computational library

This work reports the implementation and verification of a new so lver in OpenFOAM® open source computational library, able to cope with integral viscoelastic models based on the integral upper-convected Maxwell model. The code is verified through the comparison of its predictions with analytical solutions and numerical results obtained with the differential upper-convected Maxwell modelCAPES, FCT projects PEsT-C/CTM/LA0025/2013, PTDC/MAT/121185/2010 and FEDE

Numerical simulation of hydroelastic waves along a semi-infinite ice floe

With the increasing demand for Arctic Engineering purposes, Squire suggests current theories may have oversimplified the sea ice hydroelasticity, indicating the need to develop numerical models to obtain more realistic solutions. Numerical models have been reported capable of achieving a full coupling between waves and rigid floating ice. When an ice floe is relatively small to wavelength, it is valid for the floe to be considered as rigid, thus no need to solve ice deformations. However, in order to model the sea ice hydroelasticity, a Fluid-Structure Interaction (FSI) approach is required to obtain the structural solution of ice deformation and couple it with the solution of surrounding fluid domain, which requires further development of above models. To fill this gap, an FSI approach was developed based on the open-source code, OpenFOAM, and it has been validated in the case of wave interaction with a finite ice floe. In this work, the developed model is extended to a very long ice floe to study the semi-infinite scenario. Simulations are performed to present the wave-induced ice deformation, with the attenuation of hydroelastic waves along the ice floe investigated

A new integral viscoelastic flow solver in OpenFOAM®

The usual high cost of commercial codes, and some technical limitations, clearly limits the employment of numerical modelling tools in both industry and academia. Consequently, the number of companies that use numerical code is limited and there a lot of effort put on the development and maintenance of in-house academic based codes . Having in mind the potential of using numerical modelling tools as a design aid, of both products and processes, different research teams have been contributing to the development of open source codes/libraries. In this framework, any individual can take advantage of the available code capabilities and/or implement additional features based on his specific needs. These type of codes are usually developed by large communities, which provide improvements and new features in their specific fields of research, thus increasing significantly the code development process. Among others, OpenFOAM® multi-physics computational library, developed by a very large and dynamic community, nowadays comprises several features usually only available in their commercial counterparts; e.g. dynamic meshes, large diversity of complex physical models, parallelization, multiphase models, to name just a few. This computational library is developed in C++ and makes use of most of all language capabilities to facilitate the implementation of new functionalities. Concerning the field of computational rheology, OpenFOAM® solvers were recently developed to deal with the most relevant differential viscoelastic rheological models, and stabilization techniques are currently being verified. This work describes the implementation of a new solver in OpenFOAM® library, able to cope with integral viscoelastic models based on the deformation field method. The implemented solver is verified through the comparison of the predicted results with analytical solutions, results published in the literature and by using the Method of Manufactured Solution