Numerical simulation of viscoelastic fluid flow

My name is Simon Ingelsten and I am an industrial PhD student at Chalmers University of Technology, working at Fraunhofer-Chalmers Research Centre for Industrial Mathematics in Gothenburg. I started as a Development Engineer at the Fraunhofer-Chalmers Centre after graduating from Chalmers University of Technology and the master program “Engineering Mathematics and Computational Science” in 2015. After a few years in 2018, I started conducting my PhD project as part of my work, with Assoc. Prof. Roland Kádár at Chalmers as my main supervisor and Assoc. Prof. Fredrik Edelvik and Assoc. Prof. Andreas Mark at Fraunhofer-Chalmers Centre as co-supervisors.  The project is partly carried out in the Centre for Additive Manufacturing—Metal (CAM2) in a joint project financed by Swedish Governmental Agency of Innovation Systems (Vinnova), coordinated by Chalmers University of Technology. It is also supported in part by Vinnova through the FFI Sustainable Production Technology program and in part by the “Chalmers Area of Advance” Production.

More or less immediately I got involved in projects concerning computational fluid dynamics (CFD) and simulation of fluids with complex rheology. CFD is the science of using computer simulations to solve the equations which describe the mechanics of liquids and gases to predict the flow, including for example frictional stresses and pressure differences. After some time, my interest for viscoelastic fluids grew, which also led up to my PhD project. 

Simulation of automotive seam sealing. Geometry courtesy of Volvo Car Corporation.

Viscoelastic fluids are materials which behave as viscous fluids and elastic solids simultaneously, making them challenging to model numerically. On the other hand, many real-life industrial applications involve viscoelastic fluids, so there is a strong motivation to simulate different types of viscoelastic fluid flow. Examples of applications are seam sealing, adhesive joining, additive manufacturing and polymer extrusion. 

Simulation of E-swirl adhesive application.

My research revolves around developing a new simulation method for viscoelastic fluid flow. This includes calculating the stresses which arise due to the complex material properties as well as coupling these stresses to the rest of the equations which describe the flow. The goal is a robust and efficient simulation tool which can be used for simulation of industrially relevant problems with viscoelastic fluids. Adhesive joining and related applications are of particular interest. The method therefore must be numerically stable as well as computationally efficient. My project therefore spans from doing basic validation to testing the method for industrial-scale simulation cases.  

Simulation of viscoelastic fluid jet buckling.