Numerics

Numeric-Group, Berlin, 04.07.2018
© DFG-SPP-2005

Numerical simulations can help to clarify details of the complex flow processes in fresh concrete and thus deepen our understanding of its rheology. For this purpose, the “Numerics” working group in  SPP 2005 is developing numerical models that describe the movements of both individual particles and fluid phases as well as their interactions. Benchmark studies and round robin tests are used to check that these models are of high quality. They shall be used for the ongoing research within the priority program of the German Research Foundation (DFG SPP 2005).

Goals

Working Group Numerics in SPP 2005 develops numerical models which capture the dynamics of the granular and fluid phases in fresh concrete. Simulations with these models are used to research details of fresh concrete flows. In detail, WG Numerics has the following goals:

  • Implementation of data from the two other working groups in particle-based and continuum-based numerical models
  • Characterization of model performance
  • Source code and data sharing within the priority program
  • Application of the numerical models within the priority program
Figure 1: From: Haustein, M. A., Zhang, G., Schwarze, R.: Segregation of granular materials in a pulsating pumping regime, Granular Matter, 2019.
© DFG-SPP-2005

Haustein, M. A., Zhang, G., Schwarze, R., Segregation of granular materials in a pulsating pumping regime, Granular Matter, 2019

From: Secrieru, E., Mohamed, W., Fataei, S., Mechtcherine, V.: Assessment and prediction of concrete flow and pumping pressure in pipeline, Cement and Concrete Composites, 2020.
© DFG-SPP-2005

Secrieru, E., Mohamed, W., Fataei, S., Mechtcherine, V., Assessment and prediction of concrete flow and pumping pressure in pipeline, Cement and Concrete Composites, 2020

Members & Institutions

Chair

  • Rüdiger Schwarze
    TU Bergakademie Freiberg, Germany

Deputy Chair

  • Carsten Schilde
    TU Braunschweig, Germany

Members

  • Martin Haustein
    Technische Universität Bergakademie Freiberg, Germany
  • Dimitri Ivanov
    Technische Universität Braunschweig, Germany
  • Mahmoud Eslami Pirharati 
    Technische Universität Braunschweig, Germany
  • Dirk Lowke
    Technische Universität Braunschweig, Germany
  • Eddie Koenders
    Technische Universität Darmstadt, Germany
  • Neven Ukraincyzk
    Technische Universität Darmstadt, Germany
  • Shirin Fataei
    Technische Universität Dresden, Germany
  • Sergiy Shyshko
    Technische Universität Dresden, Germany
  • Viktor Mechtcherine
    Technische Universität Dresden, Germany
  • Daniel Jara-Heredia
    Universität Jena, Germany
  • Thorsten Schäfer
    Universität Jena, Germany
  • Holger Steeb
    Universität Stuttgart, Germany
  • Nadine Kijanski
    Universität Stuttgart, Germany
  • Daniel Rostan
    Universität Stuttgart, Germany
  • David Krach
    Universität Stuttgart, Germany
Institutions of working group analytic

Actions

Date

Action

Location

12.09.2019

Group meeting

Dresden

22.10.2019

Group webmeeting

Webconference

23.10.2019

Group webmeeting

Webconference

02.07.2020

Group webmeeting

Webconference

03.08.2020

Group webmeeting

Webconference

Results and Current Work

A major achievement of the working group resulted in a paper, which presented the results of an interlaboratory study of the rheological properties of cement paste and ultrasound gel as reference substance. The goal was to quantify the comparability and reproducibility of measurements of the Bingham parameters yield stress and plastic viscosity when measured on one specific paste composition and one particular ultrasound gel in different laboratories using different rheometers and measurement geometries. The procedures for both in preparing the cement paste and carrying out the rheological measurements on cement paste and ultrasound gel were carefully defined for all of the study’s participants. Different conversion schemes for comparing the results obtained with the different measurement setups are presented here and critically discussed. The procedure proposed in this paper ensured a reasonable comparability of the results with a coefficient of variation for the yield stress of 27% and for the plastic viscosity of 24%, despite the individual measurement series’ having been performed in different labs with different rheometers and measurement geometries.

Figure 3: CFD-Benchmark: Comparison of different software packages for a velocity profile of a non-Newtonian fluid after a pipe-bend
© DFG-SPP-2005

CFD-Benchmark: Comparison of different software packages for a velocity profile of a non-Newtonian fluid after a pipe-bend.

Figure 4: DEM-Benchmark: Development of integrated potential and kinetic energy of all particles in a slump flow.
© DFG-SPP-2005

DEM-Benchmark: Development of integrated potential and kinetic energy of all particles in a slump flow.