mod_eprivacy

Simulation of the mechanical deformation and movement of droplets under the influence of high electric fields

Description

We investigate droplet dynamical processes taking place under the influence of strong electric fields. Such processes play an important role in many technical applications. One example are raindrops on the surface of surge arresters and insulators in electrical power systems. These droplets undergo a continuous oscillatory motion driven by the high-voltage field of the system. As a result partial electrical discharges are triggered that can damage the surface of the arrester, thereby shortening its life. Another example is the generation of droplets in high-pressure chambers. In electrically controlled drop-on-demand generators, microdroplets are detached from the tip of a capillary using a strong electric pulse. It is thereby possible to control the volume and the timing of the produced droplets very accurately. Yet another extremely important application is the atomization of liquids by means of electric fields. The process of jet formation on the surface of conductive liquids and its further decay into a cloud of charged droplets (electrospray) remains yet to be understood.

In this project we develop numerical techniques and computational tools for the simulation of droplet dynamics and electroquasistatic fields. The fluid dynamics problem is solved using the software package OpenFOAM. For the computation of transient electric fields (and the corresponding electrical forces), both, a sharp interface approach on unstructured dynamically adapted grids as well as a phase field approach with suitable material averaging at the phase boundary are used. A numerical coupling interface between the electrical and fluid dynamic problems is developed which ensures temporal synchronization and allows for sharing simulation data between the fluid dynamics and electrical problems, respectively. The example of an oscillating droplet in the high voltage field, the droplet generator and the generation of electrosprays are the three most important applications sought for in the project. The aim is to develop a better understanding for these processes by means of numerical simulations. All simulation work in the project is performed in close collaboration with experimental partners within the framework of the Collaboration Research Center. Measurement data are used, in particular, for the validation of simulation results.

Team

PD Dr. rer. nat. habil. Erion Gjonaj

PD Dr. rer. nat. habil. Erion Gjonaj

Director subarea A5 This email address is being protected from spambots. You need JavaScript enabled to view it. +49 6151 16-2561
 Prof. Dr. rer. nat. Sebastian Schöps

Prof. Dr. rer. nat. Sebastian Schöps

Director subarea A5 This email address is being protected from spambots. You need JavaScript enabled to view it. +49 6151 16-24409
Yun Ouédraogo, M.Sc.

Yun Ouédraogo, M.Sc.

A5 This email address is being protected from spambots. You need JavaScript enabled to view it. +49 6151 16-2461
244245246

Publications

2017

Ouedraogo, Y., Gjonaj, E., Weiland, T., De Gersem H., Steinhausen C., Lamanna G., Weigand, B., Preusche, A., Dreizler, A., Schremb, M.:
Electrohydrodynamic simulation of electrically controlled droplet generation.
Int. J. of Mass and Fluid Flow, Vol. 64 (2017), pp. 120-128.

Richter, C., Schöps, S., Clemens, M.:
GPU Accelerated Explicit Time Integration Methods for Electro-Quasistatic Fields.
Appears in IEEE Trans. Magn. 2017, https://arxiv.org/abs/1612.09447.

Ouedraogo, Y., Gjonaj, E., Weiland, T., De Gersem H., Steinhausen C., Lamanna G., Weigand, B., Preusche, A., Dreizler, A.:
Modeling of an electrically driven droplet generator.
COUPLED PROBLEMS 2017, 12-14 June, Rhodes Island, Greece, 12 pages.

Ouedraogo, Y., Gjonaj, E., Weiland, T., De Gersem H., Steinhausen C., Lamanna G., Weigand, B., Preusche, A., Dreizler:
A convection-conduction model for electrohydrodynamic simulations,
In: Proc. of COMPUMAG, June 18-22, 2017, Daejeon, Korea.

2016

Yun Ouedraogo, Erion Gjonaj, Herbert De Gersem, Thomas Weiland.
Coupled Simulations of Electrically Driven Droplet Generation
Poster for the 10t International Symposium on Electric and Magnetic Fields, Lyon, 2016.

Sharanya, V.; Raja Sekhar, G. P.; Rohde, Christian;
Bed of polydisperse viscous spherical drops under thermocapillary effects.
Z. Angew. Math. Phys. 67 (2016), no. 4, 67:101.

Ouedraogo, Y., Gjonaj, E., Weiland, T., De Gersem H., Steinhausen C., Lamanna G., Weigand, B., Preusche, A., Dreizler, A.:
Modelling and simulation of electrically controlled droplet dynamics,
to appear in Scientific Computing in Electrical Engineering (SCEE 2016),
The European Consortium for Mathematics in Industry Series, Springer-Verlag, Berlin/Heidelberg (9 pages).

Richter, C., Schöps, S., Dutiné, J.S., Schreiber, R. and Clemens, R.:
Transient Simulation of Nonlinear Electro-Quasistatic Field Problems Accelerated by Multiple GPUs.
IEEE Transactions on Magnetics 52.3 (2016). Doi: 10. 1109/TMAG.2015.2466602.

Ouedraogo, Y., Gjonaj, E., Weiland, T., De Gersem H.:
Coupled Simulations of Electrically Driven Droplet Generation,
10th International Symposium on Electric and Magnetic Fields, Lyon, 2016.

2015

Songoro, H.:
Electrohydrodynamic Modeling of Droplet Vibrations under the Influence of Electric Fields.
PhD Thesis, TU Darmstadt (2015), http://tuprints.ulb.tu-darmstadt.de/4471

2014

Bartel, A., Brunk, A., Schöps, S:
On the Convergence Rate of Dynamic Iteration for Coupled Problems With Multiple Subsystems.
Journal of Computational and Applied Mathematics 262 (2014). Doi: 10.1016/j.cam.2013.07.031.

Stegmann, P., Gjonaj, E., Tropea, C.:
High‐frequency Gaussian beam scattering by ice crystals. In Scattering by Aggregates on Surfaces,
Series: ScattPort Series, Vol. 1, Wriedt, Thomas; Eremin, Yuri (Eds.) epubli, Berlin 2014, ISBN: 978-384-4299-44-1

2013

Karch, G.K., Sadlo, F., Songoro, H., Gjonaj, E., Weiland, T., Ertl, T.
Visualizing Edge-Conforming Discrete Field Quantities in Electromagnetic Field Problems with Interfaces
Eingereicht für die 5th European Conference on Liquid Atomization and Spray Systems (ILASS 2013), September 2013, Chania, Griechenland

Songoro, H., Nazemi, M.H., Gjonaj, E., Hinrichsen, V., Weiland, T.:
Water droplet oscillation on the hydro-phobic surface of polymeric insulators under AC electric field stress.
18th International Symposium on High Voltage Engineering (ISH 2013), August 2013, Seoul, Korea, 6 pages.

Nazemi, M.H., Hinrichsen, V., Gjonaj, E.
Investigations on partial discharges of polymeric insulators in the presence of oscillating water droplets on the surface.
ETG-Fachbericht, Vol. 140: Grenzflächen in elektrischen Isoliersystemen, Dresden (2013), 6 pages

2012

Froehlcke, A.; Gjonaj, E.; Weiland, T.
A boundary conformal Discontinous Galerkin approach for electro-quasistatic problems
Bastiaan Michielsen (Eds.) and Jean-René Poirier (Eds.), Scientific Computing in Electrical Engineering (SCEE 2010): The European Consortium for Mathematics in Industry, 16 (2012), 153-161, Springer-Verlag, Berlin/Heidelberg

Songoro, H.; Gjonaj, E.; Weiland T.
Computational modeling of water droplet deformations in strong electric fields.
International Conference on Electromagnetics in Advanced Applications (ICEAA 2012), Cape Town, South Africa(2012), 333-336

Songoro, H.; Gjonaj, E.; Weiland T.
Multiphysics Simulation of Water Droplets in Strong Electric Fields.
Kleinheubacher Tagung 2012 , 24-26 September 2012, Miltenberg ,Germany

Fröhlcke, A., Gjonaj, E., Weiland, T.
A boundary conformal discontinuous Galerkin approach for electro-quasistatic field problems on Cartesian grids
Int. J. Comput. Sci. Eng. Juli 2012

Fröhlke, A., Gjonaj, E., Weiland, T.
A boundary conformal Discontinuous Galerkin approach for transient electro-quasistatic problems with moving boundaries
International Conference on Electromagnetics in Advanced Applications (ICEAA 2012), Cape Town, South Africa (2012), 606-609

2011

Songoro, H.; Gjonaj, E.; Weiland, T.
Numerical Simulation of Water Droplets in presence of Strong Electric Fields.
International Conference on Electromagnetics in Advanced Applications (ICEAA 2011), Torino, Italy (2011), 504-507

Weiland, T.; Denz, F.; Songoro, H.; Gjonaj, E.; Koch, S.
Numerical Methods for Field Computation - Basics and specific problems in High Voltage applications.
Submitted to Workshop Feldsteuernde Isoliersysteme - Energie Technische Gesellschaft 2011

Songoro, H.; Gjonaj, E.; Weiland T.
Numerical Simulation of Water Droplets in presence of Strong Electric Fields.
Workshop on Advances in Electromagnetic Research, 20.-26. August 2011, Riezlern, Österreich

Weiland, T., Gjonaj, E., Koch, S.
Elektrische, thermische und mechanische Simulationen für Hochspan- nungsisoliersysteme
ETG-Fachbericht 131 zum Workshop „Feldsteuernde Isoliersysteme“, Darmstadt(2011), 47-55, VDE Verlag, Berlin, Offenbach

Classen, C., Gjonaj, E., Roemer, U., Schuhmann, R., Weiland, T.
Modeling of field singularities at dielectric edges using grid based methods
Adv. Radio Sci. 9 (2011), 39-44

Fröhlcke, A.; Songoro, H.; Gjonaj, E.; Weiland, T.
Modeling and simulation of electric field problems with moving boundaries
2nd International Conference on Computational Engineering (ICCE 2011), Oktober 2011, Darmstadt

Friday, November 15, 2019