Simulation of Multiphase Flows

For the energy generation in gas turbines, diesel engines and coalfired power stations or for the production of nanoparticles with special properties, medias with different phases are used. The streams which usual consist of a continual and dispersed phase for example gaseous phase - liquid phase (spray-combustion) or gaseous phase - solid body (cole combustion, nanoparticle syntheses) are described by Euler-Lagrange oder Euler-Euler methods at the Chair of Fluid Dynamics and simulation of reactive flows. Thereby models are developed which describe the interaction of these phases between themselves as well as the attitude of the individual phases.

The modeling is based on the implementation of physical models in our Inhouse Code PsiPhi as well as the expansion of the open sourced CFD Software OpenFOAM by introducing of new libraries and flow solvers. The resulting simulation results were justified by experimental or analytical memory whereby the models were validated. The findings are pubilished in journals or presented at conferences.

The following employees are currently working on projects in the area of Multiphase Flows:

  • Johannes Sellmann - Simulations of spray flame reactors & Simulations of the nanoparticle synthesis inside flame reactors
  • Efim Borukhovich -  Large eddy simulation of nanoparticle synthesis

Selected Publications

  • Tufano, G., Stein, O. T., Wang, B., Kronenburg, A., Rieth, M., Kempf, A. M., (accepted 2018) Coal particle volatile combustion and flame interaction. Part II: Effects of particle Reynolds number and turbulence, Fuel.
  • Rieth, M., Rabacal, M., Kempf, A., Kronenburg, A., Stein, O. T., Carrier-phase DNS of biomass particle ignition and volatile burning in a turbulent mixing layer, Chemical Engineering Transactions 65 (2018) 37-42 PDF
  • Rieth, M., Kempf, A., Kronenburg, A., Stein, O. T., Carrier-phase DNS of pulverized coal particle ignition and volatile burning in a turbulent mixing layer, Fuel 212 (2018) 364-374.
  • Rittler, A., Large eddy simulation of nanoparticle synthesis from spray flames, PhD Thesis (2017). PDF
  • Rieth, M. Large Eddy and Direct Numerical Simulation of Single and Multiphase Flows Relying on Lagrangian Particle Methods, PhD Thesis (2017). PDF
  • Rieth, M., Proch, F., Clements, A. G., Rabaçal, M., Kempf, A., Highly resolved flamelet LES of a semi-industrial scale coal furnace, Proc. Combust. Inst. 36:3 (2017) 3371–3379.
  • Rieth, M., Proch, F., Rabaçal, M., Franchetti, B. M., Marincola, F. C., Kempf, A., Flamelet LES of a semi-industrial pulverized coal furnace, Combust. Flame, 173 (2016) 39-56.
  • Rabacal, M., Franchetti, B. M., Marincola, F. C., Proch, F., Costa, M., Hasse, C., Kempf, A., Large eddy simulation of coal combustion in a large-scale laboratory furnace, Proc. Comb. Inst. 35:3 (2015) 3609-3617.
  • Franchetti, B. M., Marincola, F. C., Navarro-Martinez, S., Kempf, A., Large eddy simulation of a pulverised coal jet flame, Proc. Comb. Inst. 34:2 (2013) 2419-2426.
  • Stein, O. T., Olenik, G., Kronenburg, A., Marincola, F. C., Franchetti, B. M., Kempf, A., Ghiani, M., Vascellari, M., Hasse, C., Towards comprehensive coal combustion modelling for LES, Flow Turb. Combust. 90:4 (2013) 859-884.
  • Franchetti, B. M., Marincola, F. C., Navarro-Martinez, S., Kempf, A., Large eddy simulation of a pulverised coal jet flame, Proc. Combust. Inst. 34:2 (2013) 2419-2426.

illustration of temperature in the near burner region.

illustration of oxygen mass fraction in the mid axial section of a large-scale laboratory furnace (diameter = 600 mm).

Illustration of the pulverised coal jet jet flame:
Instantaneous images of the fields of
(a) temperature,
(b) volatile content mass fraction,
(c) oxygen mass fraction,
(d) mean axial velocity,
(e) char mass fraction.

Electric potential within an electrostatic filter, soot particles dispersed in the air stream.

Instantaneous snapshots of the liquid particles, the mixture fraction and the temperature predicted by the simulations for the Sydney piloted spray burner.

Instantaneous snapshots of the OH concentration as measured by the experiments (left) and predicted by the simulations.

Photography and simulation of a spray flame
a) snapshot with 400 ns exposure time
b) mean of the snapshots
c) simulated temperature field