Using STAR-CCM+ for Research and Teaching at the Chair of Chemical & Process Engineering P ROF . D R .-I NG . M. K RAUME , G. W EHINGER , T. E PPINGER Chair of Chemical & Process Engineering Technische Universität Berlin STAR Global Conference 2014 (March 17-19), Vienna
Content 1. Introducing the chair of chemical & process engineering at TU Berlin 2. Single-phase research 3. Multi-phase research 4. Teaching CFD Slide 2 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
TU Berlin – Chair of chemical & process engineering Slide 3 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
SINGLE-PHASE RESEARCH Slide 4 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Single-phase stirrer vessels Temperature • Enzymatic membrane reactor pH control control 70 mm x 40 mm 90 mL Volume Adapter H/D ≈ 1,8 Stirrer with d/D ≈ 0,9 Membrane at bottom • Single-phase CFD simulations: Inlet – Membrane fouling characteristics Membrane – Stirrer momentum Stirrer – Mixing time Shaft Outlet Lyagin et al. (2012). Chemical Engineering , 27 Slide 5 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Membrane fouling and shear stress Shear stress [PA] Enzyme: Acylase from Aspergillus Melleus Lyagin et al. (2012) Procedia Engineering , 44, 391-393. Slide 6 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Spatially resolved catalytic fixed-bed reactors DARS DEM Calculation of detailed (discrete element method) homogeneous and heterogeneous Generation of a random packing reaction mechanism Spatially Resolved Simulation of Fixed-Bed Reactors CFD - STAR-CCM+ Pore model Calculation of fluid dynamics, Calculation of processes within temperature and species pores concentration Slide 7 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Fixed bed generation using DEM simulations Filling by DEM-simulation Fixed-bed geometry Meshing CFD simulation Spherical particles Non-spherical particles Eppinger et al. (2011). Chemical Engineering Journal , 166 (1), 324-331. Slide 8 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Work flow – non-spherical particles Raschig rings Raschig rings Cylinders one hole four hole D/d = 8.8 D = 0.22m d = h = 0.025m H = 0.55m Slide 9 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Catalytic fixed-bed reactors Coupling spatially complex geometries with detailed surface reactions Heterogeneous dry reforming of methane (42 irreversible reactions) 𝑤 𝑒 𝑞 𝑆𝑓 𝑞 = 𝜉 = 28 , T wall = 700 °C See the presentation by Gregor Wehinger : “Spatially Resolved Simulations of Heterogeneous Dry Reforming of Methane in Fixed- Bed Reactors” from 2:00 pm to 2:25 pm, Klimt I. Slide 10 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Mixing in biogas plants Challenges: • Shear thinning and viscoelastic fluids • multi-phase systems: solid, liquid and gaseous Biogas plant: substrate: corn silage 2 submersible mixers volume: 2500m³ Requirement: Correspondence of the agitators S = 39 [Pa∙s 0.12 ] ∙ (0.12-1) 0 = 1000 Pa∙s ∞ = 0.34 Pa∙s Slide 11 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Mixing in biogas plants Cavern forming in high viscous, shear thinning fluids the correspondence of the agitators breaks down 2.40 1.92 1.44 0.96 0.48 0.00 Slide 12 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Permeation through a semipermeable membrane Feed side: c F (x,y,z) Retentate Feed 𝑵 Membrane 𝑵 Mass transfer as concentration dependent boundary condition Permeate side: c P (x,y,z) Permeate 𝑮 − 𝒅 𝒋 𝑸 𝒚,𝒜,𝒛=𝟏 For each component i: 𝑵 𝒋 𝒚, 𝒜 = 𝑴 𝑩 𝒅 𝒋 Concentration difference between Permeance feed and permeate side on Mass flow Area membrane surface Implementation as user function Slide 13 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Application Details Gas permeation test cell Cross section Fluid volume Mesh Input Parameters Methane and n-butane mixture • p Feed , p Perm , 𝑊 𝐺𝑓𝑓𝑒 • Permeance L of membrane material • Trimmed Mesh • Slide 14 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Results Velocity profile Concentration profile Transmembrane -6,3*10 -5 kg/m² s bar mass transfer of n-butane: -6,6*10 -5 kg/m² s bar Slide 15 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
MULTI-PHASE RESEARCH Slide 16 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Multi-phase slim stirrer reactors • Combining CFD simulations and population balance equation drop size and power consumption Slide 17 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Power number and Sauter mean diameter Slide 18 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
VOF-simulation of a silicon oil liquid film 0 cm Film with constant height 4 cm Regular beads Irregular beads due to coalescence 20cm Fewer but higher and faster beads 28 cm Wehinger et al. Chemical Engineering Science 104 (2013): 934-944. Slide 19 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Mass transfer at vertical liquid film Specific interfacial area depending on Mean gas-side Sherwood number gas load depending on Reynolds number Slide 20 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
TEACHING CFD Slide 21 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Teaching • Students are CFD users, not programmers • Theory: as much as necessary • Focus: solving engineering problems • Advantages of STAR-CCM+: CAD CAD modeler mostly simple geometries Post- GUI processing Hierarchical model selection Reports, Monitors, Animations Slide 22 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Example: Hippopotamus pool in the zoo of Berlin • Three hippopotami in the pool • Water turbidity in the pool due to biomass disposal • Pool: 600 m³ and 160 m³/h Velocity distribution and residence time Simplified geometric model Slide 23 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Water turbidity by evaluating velocities Velocity distribution at different levels in the hippopotamus pool Dead zones indicates water turbidity Pressure outlets Velocity inlet Slide 24 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Conclusion • We are applying computational fluid dynamics regularly. • Special objections need special solutions, e.g., user defined subroutines. • CFD accompanies and/or enriches specific experiments at different length and time scales. • CFD references and is likewise referenced by experiments. Slide 25 Chair of Chemical & Process Engineering STAR Global Conference 2014 www. verfahrenstechnik.tu-berlin.de Vienna, March 17-19, 2014
Thank you for your attention. Prof. Dr.-Ing. M. Kraume, G. Wehinger, T. Eppinger Chair of Chemical & Process Engineering Technische Universität Berlin STAR Global Conference 2014 (March 17-19), Vienna
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