Abstract
Particle-Based Modelling of Free-Surface Flow and Distributive Mixing in Modular Co-Rotating Twin-Screw Extruders
SPH and 1D Simulations of HME
J. Matić, IPPT – TU Graz, Graz, Austria
A. Eitzlmayr, IPPT – TU Graz, Graz, Austria
I. Kondor, RCPE, Graz, Austria
G. Koscher, RCPE, Graz, Austria
J. Khinast, IPPT – TU Graz and RCPE, Graz, Austria
Email for correspondence: khinast@tugraz.at
Abstract
Extruders have been established in the polymer, rubber and food industries for decades. In recent years, they attracted increasing interest in the pharmaceutical industry due to their potential for the manufacturing of solid drug products.
However, the modeling of flow and mixing in co-rotating twin-screw extruders is still highly challenging. Mesh-based computational fluid dynamics (CFD) methods require sophisticated re-meshing techniques to account for the complex, rotating screw geometries, and struggle with free surface flows. Due to the obvious challenges of the rotating screw geometry for mesh-based methods we investigated the applicability of the smoothed particle hydrodynamics (SPH) method, which models the flow by Lagrangian fluid elements, so-called “particles”, and is therefore a mesh-less, particle-based approach. In contrast to mesh-based CFD, not only the rotating screw geometry is less problematic, but SPH can also account for free-surface flows without additional modeling effort. Moreover, distributive mixing can be easily studied by tracking tracer particles. For the implementation we used the open-source particle simulator LIGGGHTS (www.liggghts.com). With that, we investigated flow and mixing in different types of screw elements for complete and partial filling. In addition, we investigated a scale-up scenario using 1D mechanistic modelling and data gained from the SPH simulation as input. As a result we gained information about the filling level, temperature and pressure profiles, specific mechanical energy input and mixedness along the screw.
SPH and 1D Simulations of HME
J. Matić, IPPT – TU Graz, Graz, Austria
A. Eitzlmayr, IPPT – TU Graz, Graz, Austria
I. Kondor, RCPE, Graz, Austria
G. Koscher, RCPE, Graz, Austria
J. Khinast, IPPT – TU Graz and RCPE, Graz, Austria
Email for correspondence: khinast@tugraz.at
Abstract
Extruders have been established in the polymer, rubber and food industries for decades. In recent years, they attracted increasing interest in the pharmaceutical industry due to their potential for the manufacturing of solid drug products.
However, the modeling of flow and mixing in co-rotating twin-screw extruders is still highly challenging. Mesh-based computational fluid dynamics (CFD) methods require sophisticated re-meshing techniques to account for the complex, rotating screw geometries, and struggle with free surface flows. Due to the obvious challenges of the rotating screw geometry for mesh-based methods we investigated the applicability of the smoothed particle hydrodynamics (SPH) method, which models the flow by Lagrangian fluid elements, so-called “particles”, and is therefore a mesh-less, particle-based approach. In contrast to mesh-based CFD, not only the rotating screw geometry is less problematic, but SPH can also account for free-surface flows without additional modeling effort. Moreover, distributive mixing can be easily studied by tracking tracer particles. For the implementation we used the open-source particle simulator LIGGGHTS (www.liggghts.com). With that, we investigated flow and mixing in different types of screw elements for complete and partial filling. In addition, we investigated a scale-up scenario using 1D mechanistic modelling and data gained from the SPH simulation as input. As a result we gained information about the filling level, temperature and pressure profiles, specific mechanical energy input and mixedness along the screw.
| Original language | English |
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| Publication status | Published - 21 Apr 2016 |
| Event | PARTEC 2016 - Nürnberg, Germany Duration: 19 Apr 2016 → 21 Apr 2016 https://www.partec.info/ |
Conference
| Conference | PARTEC 2016 |
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| Country/Territory | Germany |
| City | Nürnberg |
| Period | 19/04/16 → 21/04/16 |
| Internet address |