Simulation of Droplet Jetting of a Non-Newtonian Mixed Suspension
Paper i proceeding, 2016

The jet printing of a dense mixed non-Newtonian suspension is based on the rapid displacement of fluid through a nozzle, the forming of a droplet and eventually the break-off of the filament. The ability to model this process would facilitate the development of future jetting devices. The purpose of this study is to propose a novel simulation framework and to show that it captures the main effects such as droplet shape, volume and speed. In the framework, the time dependent flow and the fluid-structure interaction between the suspension, the moving piston and the deflection of the jetting head is simulated. The system is modelled as a two phase system with the surrounding air being one phase and the dense suspension the other. Hence, the non-Newtonian suspension is modelled as a mixed single phase with properties determined from material testing. The simulations were performed with two coupled in-house solvers developed at Fraunhofer-Chalmers Centre; IBOFlow, a multiphase flow solver and LaStFEM, a large strain FEM solver. Jetting behaviour was shown to be affected not only by piston motion and fluid rheology, but also by the energy loss in the jetting head. The simulation results were compared to experimental data obtained from an industrial jetting head.

solder paste

jetting

SMT

Multiphase flow

granular suspension

computational fluid dynamics

Författare

Martin Svensson

Fredrik Edelvik

Andrzej Karawajczyk

Gustaf Mårtensson

Chalmers, Mikroteknologi och nanovetenskap (MC2)

ICMF-2016 – 9th International Conference on Multiphase Flow May 22nd – 27th 2016, Firenze, Italy

Styrkeområden

Nanovetenskap och nanoteknik

Produktion

Ämneskategorier

Matematik

Beräkningsmatematik

Strömningsmekanik och akustik

Fundament

Grundläggande vetenskaper

Mer information

Skapat

2017-10-07