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2/09/2014 | pag. 1 Novel Multiscale approach to Transport phenomena in Electrochemical Processes Integrating the research of different partners SBO 04.

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Presentation on theme: "2/09/2014 | pag. 1 Novel Multiscale approach to Transport phenomena in Electrochemical Processes Integrating the research of different partners SBO 04."— Presentation transcript:

1 2/09/2014 | pag. 1 Novel Multiscale approach to Transport phenomena in Electrochemical Processes Integrating the research of different partners SBO May 2008 Heidi Van Parys, Thomas Nierhaus, Pedro Maciel, Steven Van Damme Mutech

2 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 2 Outline  Introduction of the team  Test reactors  Software approach  Flow solvers  Single phase flow  Two phase flow  Extending the team S

3 Vakgroep elektrotechniek Mutech  Introduction of the team Heidi Van Parys –IRDE Experiments Thomas Nierhaus –Morpheus and PLaS Pedro Maciel –COOLFluiD Steven Van Damme –MITReM library Titel van de presentatie 2/09/2014 | pag. 3 S

4 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 4  Test reactors Parallel flow reactor (PFR) S

5 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 5  Test reactors Inverted rotating disc electrode (IRDE) S

6 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 6  Software approach Flow solver Morpheus or COOLFluiD Electrochemical solver MITReM library Bubble solver PLaS Post processing Flow field Gas molar production rate Bubble size distribution Bubble velocity Bubble position Momentum exchange Gas volume fraction S

7 Vakgroep elektrotechniek Mutech  Software approach Governing equations –Fluid flow Continuous representation Incompressible Navier-Stokes Closure relation for momentum transfer (bubbles) Titel van de presentatie 2/09/2014 | pag. 7  Software approach P

8 Vakgroep elektrotechniek Mutech  Software approach Governing equations –Electrochemistry Bruggeman model Bubble production model Titel van de presentatie 2/09/2014 | pag. 8  Software approach S

9 Vakgroep elektrotechniek Mutech  Software approach Governing equations –Bubble equation motion (Euler-Lagrange) Mass-point approximation Sphericity assumption Drag, lift, virtual mass & buoyancy forces Momentum-back coupling on the flow Titel van de presentatie 2/09/2014 | pag. 9  Software approach T

10 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 10  Flow solvers Morpheus –Navier-Stokes solver with plug-in extensions –Two-phase flow (PLaS interface) –Electrochemistry (MITReM interface) –Widely portable (Linux, Windows, Mac...) –Parallel computations (MPI) –Limited dependence on external packages –Parallel linear solvers (SAMGp, Trilinos, SuperLU) –Meshing tool (Metis) –Tecplot –MPI distribution (LAM, MPICH, OpenMPI) T

11 Vakgroep elektrotechniek Mutech Morpheus –Fast and robust time integration scheme –Crank-Nicholson with convective velocity extrapolation –Large time steps with a single linear solve –Unstructured tetrahedral (3D) grids –Space discretization by Finite Elements –Galerkin FEM with stabilization terms –At least 2 nd order accuracy in time and space  Flow solvers Titel van de presentatie 2/09/2014 | pag. 11 T

12 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 12  Flow solvers COOLFluiD –Multi-physics solver –Fluid flow RDS spacial discretization Incompressible Navier-Stokes (Single-phase, Steady-state) RANS turbulence modeling (k-e / k-w) –Link to electrochemistry code MITReM library (Electrolyte & electrostatic models) Convection + diffusion + migration + reactions –Link to particle tracking code PLaS library P

13 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 13  Single phase flow MITReM Model –Electrochemistry ComponentD (10 −9 m 2 /s)c (mol/m 3 ) H+H Na SO 4 2− H20 Electrode reactionk ox k red α ox α red H  H + + e − 04e-6 m/s00.5 2H 2 O  O 2 + 4H + + 4e − 1e-12 mol/m 2 s S

14 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 14  Single phase flow PFR with MITReM –κ = 1.74 S/m –Polarization curves H 2 reaction O 2 reaction S

15 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 15  Single phase flow PFR with MITReM –Current response S

16 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 16  Single phase flow PFR with MITReM –Current density profile at 2V S

17 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 17  Single phase flow PFR with MITReM –c H profile at 2V m/s m/s m/s S

18 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 18  Single phase flow PFR with MITReM –If the total current and even the current density distribution is the same, the dissolved gas concentration can be very different depending on the hydrodynamics. –J  same bubble production. –c H  very different bubble production.  See Flora for experimental observations S

19 Vakgroep elektrotechniek Mutech  Single phase flow PFR flow field –COOLFluiD P Titel van de presentatie 2/09/2014 | pag. 19  Single phase flow PFR flow field –COOLFluiD –Laminar (Re~100) V inlet ~ 1e-2 m/s –Computational grid ~ nodes Electrochemistry layer (1e-6m) flow

20 Vakgroep elektrotechniek Mutech  Single phase flow Titel van de presentatie 2/09/2014 | pag. 20 IRDE flow field –Morpheus simulations –Flow fields for different rpm –250rpm –500rpm –1000rpm –Computational grid – nodes – tetrahedral elements –Electrochemistry layer (1e-6m) –Fluid boundary layer (2e-4m) T

21 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 21  Single phase flow IRDE flow field –Rotation-induced vetical downflow velocity 250rpm 500rpm T

22 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 22  Single phase flow IRDE flow field –Rotation-induced vertical downflow velocity 250rpm 500rpm T

23 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 23  Two phase flow PFR with bubbles –SFELES/PLaS simulations –Flow speeds in the PFR m/s – 10 m/s –Reynolds number range 20 – –Laminar & turbulent flow regimes T

24 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 24  Two phase flow PFR with bubbles –Fully turbulent model channel (Re=2600) –Advection & buoyancy play macroscopic role –TBL interaction plays mesoscopic role Bubbles align with vortices in TBL (Centripetal force) Bubbles move faster in high- speed streaks (Drag) T

25 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 25 PFR with bubbles and MITReM –Fully coupled simulations –Laminar flow conditions – Steady-state flow (COOLFluiD) – Unsteady flow (Morpheus) –Real geometry (0.864m * 0.1m * 0.01m) P

26 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 26 P  Two phase flow –∆V=0.2V Cathode at bottom Anode on top (downstream) –Laminar (Re=100) V inlet ~ 1e-2 m/s –Computational grid ~ nodes Electrochemistry layer (1e-6m) –Parallel P PFR with MITReM and dissolved H

27 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 27 P  Two phase flow PFR with MITReM and dissolved H P

28 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 28 P  Two phase flow PFR with MITReM and H bubbles P Movie!Current density –∆V=2.0V –~Laminar? V in 1m/s...

29 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 29 P  Two phase flow PFR with MITReM and H bubbles P Movie!Dissolved H –∆V=2.0V –~Laminar? V in 1m/s...

30 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 30 IRDE with bubbles –Experimental data for 250rpm Test case: H 2 -bubbles 0.1M Na 2 SO 4 / pH = 2.5 2H e -  H 2 Potential: -2V/ NHE T

31 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 31 IRDE with bubbles –Quantitative evaluation of two-phase flow Experiment Mean: μm Std: μm Bubble size distribution for 0rpm T Simulation input Mean: μm Std: μm

32 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 32 IRDE with bubbles –Quantitative evaluation of two-phase flow Bubble size distribution for 250rpm Experiment Mean: μm Std: μm Simulation Mean: μm Std: μm T

33 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 33 IRDE with bubbles –Quantitative evaluation of two-phase flow Bubble size distribution for 250rpm Experiment Mean: μm Std: μm Simulation Mean: μm Std: μm T

34 Vakgroep elektrotechniek Mutech  Two phase flow Titel van de presentatie 2/09/2014 | pag. 34 IRDE with bubbles –Morpheus/PLaS simulations –Diameter spectrum from experiments at 0rpm 250rpm 500rpm 1000rpm T

35 Vakgroep elektrotechniek Mutech Titel van de presentatie 2/09/2014 | pag. 35  Extending the team Additional future collaborations –Flora Tomasoni Measurements in the PFR Post-processing of electrochemical solver output (J, c,...) to bubble solver input (d, v,...) –Pawel Skuza Micro-scale simulations of bubble evolution from electrodes Correlations for macro-scale (MITReM) S


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