Session Details

13:30
Compressible Flows inside Piston Ring Pack Simulated with Space-Time Finite Elements
Max von Danwitz (RWTH Aachen University), Norbert Hosters (RWTH Aachen University), Marek Behr (RWTH Aachen University)

Kurzfassung:
The fuel efficiency of an internal combustion engine is directly related to the performance of the piston ring pack. We present our numerical study of compressible gas flow in the ring pack. Namely, a two-dimensional transient full engine working cycle simulation considering the fluid-rigid-body interaction between piston ring and surrounding fluid, and a three-dimensional simulation of the flow through the ring gap investigating the gap's suction effect.

13:50
Phase-Field Modeling of Multiple Phase Change Materials (PCMs)
Abdel Hassan Sweidan (RWTH Aachen University), Heider Yousef (RWTH Aachen University), Bernd Markert (RWTH Aachen University)

Kurzfassung:
A latent heat storage medium with various heat transfer enhancement techniques is being studied. The methods include using multiple immiscible PCM constituents with different melting temperatures and adding highly conductive fins. The system is modeled using the finite element method and the phase-field method is employed as a numerical approach to account for the phase change process. This method relies on specification of free energy density function and employs a phase-field variable that defines the state of the material, and it also allows for realistic simulations of dendritic growth (including anisotropy) and other solidification microstructures.

14:10
Preliminary calibration of a phase-field model for cracks due to shrinkage in cement-based materials
Tuanny Cajuhi (Technical University of Braunschweig), Pietro Lura (Swiss Federal Laboratories for Materials Science and Technology, EMPA), Laura De Lorenzis (Technical University of Braunschweig)

Kurzfassung:
Shrinkage in cement-based materials can lead to early microcracking. The phenomenon is related to the change of volume at early states, which can lead to cracking if the medium is either internally or externally restrained. Objective of this work is to describe drying shrinkage and autogenous shrinkage in cementitious materials within the framework of poromechanics and phase-field modeling with special focus on crack initiation and evolution. A preliminary calibration of the material parameters is performed in this paper.

14:30
A study of temperature and strain rate dependent glass fracture behaviour
Ziyuan Li (RWTH Aachen University), Yousef Heider (RWTH Aachen University), Bernd Markert (RWTH Aachen University)

Kurzfassung:
In this contribution, the numerical simulation of brittle fracture of glass materials under room temperature is carried out on a continuum-mechanical scale using the theory of linear elasticity and J-integral, extended by a phase-field modeling (PFM) approach. Following this, behaviors such as crack nucleation, propagation, and bulk material fracture can be realized. Moreover, fracture stresses and J-integral values are compared to analyze material toughness.