- E-postalex.hoffmann@uib.no
- Telefon+47 55 58 28 76
- BesøksadresseAllégaten 555007 Bergen
- PostadressePostboks 78035020 Bergen
Transport af bevægelsesmængde, varme og masse i flerfasesystemer. Har intet at gøre med insekter.
Vitenskapelig artikkel
- (2022). Flow loop study of a cold and cohesive slurry. Pressure drop and formation of plugs. Fuel.
- (2020). Single-Cell Tests to Explore the Reliability of Sofc Installations Operating Offshore. Energies.
- (2020). First and second-order models for the vortex length in cylinder-on-cone cyclones based on large-eddy simulations. Heliyon. 9 sider.
- (2020). A note on the multiphase balance equations. Powder Technology. 145-148.
- (2019). Positron emission particle tracking and CFD investigation of hydrocyclones acting on liquids of varying viscosity. Chemical Engineering Science (CES). 310-319.
- (2019). A study of transfer rates of phenols from caustic to crude oil. Separation and Purification Technology. 515-519.
- (2019). A correlation giving improved description of the capacity and efficiency of vane-type gas-liquid separators. AIChE Journal.
- (2019). A brief review on the effect of particle size on the laminar burning velocity of flammable dust: application in a CFD tool for industrial applications. Journal of Loss Prevention in the Process Industries. 1-6.
- (2018). Physico-chemical properties of nanocrystalline YSZ powders as a function of doping level and electrical properties after sintering. Materials Science for Energy Technologies. 136-145.
- (2017). Tape Casting of Lanthanum Chromite for Solid Oxide Fuel Cell Interconnects. Journal of Materials Processing Technology. 270-279.
- (2017). SOFC Cathode Degradation due to Salt Contamination. ECS Transactions. 915-925.
- (2017). Pressure-Driven Gas Flow through Nano-Channels at High Knudsen Number. Journal of Nano Research. 116-127.
- (2017). Non-invasive studies of multiphase flow in process equipment. Positron emission particle tracking technique. Journal of Physics: Conference Series (JPCS). 1-7.
- (2017). Effect of Oxygen Depletion to the Cathode on the Working of Solid Oxide Fuel Cells. ECS Transactions. 875-887.
- (2016). Modelling agglomeration and deposition of gas hydrates in industrial pipelines with combined CFD-PBM technique. Chemical Engineering Science (CES). 45-57.
- (2016). Apparatus for measuring pressure-driven transport through channels at high Knudsen numbers. Review of Scientific Instruments.
- (2016). A parametric study of cohesive particle agglomeration in a shear flow : numerical simulations by the discrete element method. Journal of Dispersion Science and Technology. 611-620.
- (2015). A Lagrangian study of liquid flow in a reverse-flow hydrocyclone using positron emission particle tracking. Experiments in Fluids.
- (2014). Removal of particles from highly viscous liquids with hydrocyclones. Chemical Engineering Science (CES). 169-175.
- (2014). Order Parameters and Algorithmic Approaches for Detection and Demarcation of Interfaces in Hydrate−Fluid and Ice−Fluid Systems. Journal of Chemical Theory and Computation. 5606-5615.
- (2014). Coupling STAR-CD with a population-balance technique based on the classes method. Powder Technology. 47-54.
- (2014). Collisions between particles in multiphase flows: Focus on contact mechanics and heat conduction. International Journal of Heat and Mass Transfer. 674-687.
- (2013). PEPT: an invaluable tool for 3-D particle tracking and CFD simulation verification in hydrocyclone studies. The European Physical Journal Conferences. 8 sider.
- (2013). PEPT - A novel tool for investigation of pneumatic conveying. Powder Technology. 87-96.
- (2013). Micromechanics of agglomeration forced by the capillary bridge: The restitution of momentum. AIChE Journal. 4045-4057.
- (2013). Heat conduction during collisions of cohesive and viscoelastic particles. International Journal of Heat and Mass Transfer. 107-116.
- (2012). Using a PET Camera to Track Individual Phases in Process Equipment with High Temporal and Spatial Resolutions: Algorithm Development. IEEE Instrumentation and Measurement Technology Conference. Proceedings. 2326-2330.
- (2012). The formation of deposit in a magnetic fluid: Numerical and experimental study. Powder Technology. 108-114.
- (2012). The collision efficiency in a shear flow. Chemical Engineering Science (CES). 305-312.
- (2012). Free energy of separation of structure II clathrate hydrate in water and a light oil. Journal of Physical Chemistry B. 5933-5940.
- (2012). Experimental and computational study of the "end of the vortex" phenomenon in reverse-flow centrifugal separators. AIChE Journal. 1371-1380.
- (2012). Effect of the 'end of the vortex' phenomenon on the particle motion and separation in a swirl tube separator. Powder Technology. 101-107.
- (2012). Deposition capabilities of turbulent particle-laden flow passing an obstacle using experiment and CFD. AIP Conference Proceedings. 217-219.
- (2012). CFD Modeling of PEPT Results of Particle Motion Trajectories in a Pipe over an Obstacle. AIP Conference Proceedings. 193-196.
- (2011). Particle flow in a hydrocyclone investigated by positron emission particle tracking. Chemical Engineering Science (CES). 4203-4211.
- (2011). Numerical study on the dynamics of a jet-vortex interaction. Applied Mathematics and Computation. 5103-5112.
- (2011). Numerical Study of the "End of the Vortex" Phenomenon in a Hydrocyclone Separator. AIP Conference Proceedings. 183-186.
- (2011). Large Eddy Simulation of the vortex end in reverse-flow centrifugal separators. Applied Mathematics and Computation. 5016-5022.
- (2011). Extended hard-sphere model and collisions of cohesive particles. Physical Review E. Statistical, Nonlinear, and Soft Matter Physics.
- (2011). Experimental study and computational fluid dynamics modeling of deposition of hydrate particles in a pipeline with turbulent water flow. Chemical Engineering Science (CES). 755-765.
- (2011). Examination of the co-sintering process of thin 8YSZ films obtained by dip-coating on in-house produced NiO-YSZ. Journal of the European Ceramic Society. 1733-1739.
- (2011). Dip-coating of 8YSZ nanopowder for SOFC applications. Ceramics International. 2869-2877.
- (2011). Certainties and uncertainties in CFD prediction of the end of the vortex behaviour in centrifugal separators. AIP Conference Proceedings. 135-138.
- (2011). CFD model for the magnetically forced formation of an obstructive deposit in a magnetorheological fluid. AIP Conference Proceedings. 110-113.
- (2010). Turbulent flow of hydrates in a pipeline of complex configuration. Chemical Engineering Science (CES). 5007-5017.
- (2010). Turbulent flow of freon R11 hydrate slurry. Journal of Petroleum Science and Engineering. 177-182.
- (2010). Transport, chemical and electrochemical processes in a planar SOFC: Detailed three-dimensional modeling. Journal of Power Sources. 6764-6773.
- (2010). Studies of the flow in and around gas dedusters and demisters using neutrally buoyant tracer. Chemical Engineering Journal. 11-18.
- (2010). Quantification of the adhesive impulse for the extended hard-sphere model. AIP Conference Proceedings. 163-166.
- (2010). Population Balance Model for Nucleation, Growth, Aggregation, and Breakage of Hydrate Particles in Turbulent Flow. AIChE Journal. 2052-2062.
- (2010). Eulerian-Eulerian CFD model for the sedimentation of spherical particles in suspensions with high particle concentrations. Engineering Applications of Computational Fluid Mechanics. 116-126.
- (2010). Effects of heat sources on the performance of a planar solid oxide fuel cell. International Journal of Hydrogen Energy. 4276-4285.
- (2010). Combined CFD/Population Balance Model for gas hydrate particle size prediction in turbulent pipeline flow. AIP Conference Proceedings. 151-154.
- (2010). An extension of the hard-sphere particle-particle collision model to study agglomeration. Chemical Engineering Science (CES). 3231-3239.
- (2009). The effect of polydispersity on dust lifting behind shock waves. Powder Technology. 194-201.
- (2009). Sintering of 4YSZ (ZrO2+4 mol% Y2O3) nanoceramics for solid oxide fuel cells (SOFCs), their structure and ionic conductivity. Journal of the European Ceramic Society. 2537-2547.
- (2009). Simulation of solid particles behaviour in a driven cavity flow. Powder Technology. 327-339.
- (2009). Simulation of solid particles behaviour in a driven cavity flow. Powder Technology. 327-339.
- (2009). Physico-chemical characterization of 8ysz nanoparticles by modified sol-gel method. Studia Universitatis Babeş-Bolyai Chemia.. 261-272.
- (2009). Numerical analysis of a planar anode-supported SOFC with composite electrodes. International Journal of Hydrogen Energy. 3488-3499.
- (2009). Modified sol-gel method used for obtaining SOFC electrolyte materials. ECS Transactions. 1679-1686.
- (2009). Modeling of transport, chemical and electrochemical phenomena in a cathode-supported SOFC. Chemical Engineering Science (CES). 3000-3009.
- (2009). Large eddy simulation of the vortex end in reverse-flow centrifugal separators. AIP Conference Proceedings. 641-644.
- (2009). Jet-vortex interaction: a numerical study. AIP Conference Proceedings. 617-620.
- (2009). Interfacial tension measurement of freon hydrates by droplet deposition and contact angle measurements. Journal of Petroleum Science and Engineering. 209-217.
- (2009). Extension of the hard-sphere particle-wall collision model to account for particle deposition. Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. 061302.
- (2009). Detailed modeling of an anode-supported solid oxide fuel cell using a fully three-dimensional approach. ECS Transactions. 1231-1240.
- (2008). Three-dimensional simulation of a dust lifting process with varying parameters. International Journal of Multiphase Flow. 869-878.
- (2008). Simulation of a dust lifting process with rough walls. Chemical Engineering Science (CES). 3864-3876.
- (2008). Obtaining YSZ nanoparticles by the sol-gel method with sucrose and pectin as organic precursors. Journal of Materials Processing Technology. 316-320.
- (2008). Numerical modelling of a solid oxide fuel cells: a charge diffusion-based model. Chemical Engineering Science (CES). 5356-5365.
- (2008). Numerical modeling of solid oxide fuel cells. Chemical Engineering Science (CES). 5356-5365.
- (2008). NiO/YSZ nanoparticles obtained by new sol-gel route. Chemical Engineering Journal. 586-592.
- (2008). Multiphase stochastic model for fluidized beds. Physical Review E. Statistical, Nonlinear, and Soft Matter Physics.
- (2008). Influence of collision algorithm parameters on statistical results of dust lifting simulations. AIP Conference Proceedings. 815-818.
- (2008). Experimental investigation of the performance of a large-scale scrubber operating at elevated pressure on live natural gas. Fuel. 1281-1288.
- (2008). Eulerian-Eulerian simulation of sedimentation of uniformly-sized, non-Brownian spheres in viscous fluids. AIP Conference Proceedings. 723-726.
- (2008). Effect of calcination conditions and precursor proportions on the properties of YSZ nanoparticles obtained by modified sol-gel route. Chemical Engineering Journal. 608-615.
- (2008). An experimental investigation of scrubber internals at conditions of low pressure. Chemical Engineering Journal. 95-102.
- (2007). Reverse-flow centrifugal separators in parallel: Performance and flow pattern. AIChE Journal. 589-597.
- (2007). Re-entrainment correlations for demisting cyclones acting at elevated pressures on a range of fluids. Energy & Fuels. 2969-2976.
- (2007). Numerical Simulation of Electrochemical and Transport Processes in Solid Oxide Fuel Cells. ECS Transactions. 1901-1908.
- (2007). Is the Souders-Brown equation sufficient for scrubber design? An experimental investigation at elevated pressure with hydrocarbon fluids. Chemical Engineering Science (CES). 5715-5727.
- (2007). Fuel cells and nanoparticles. Studia Universitatis Babeş-Bolyai Chemia.. 3-12.
- (2007). Dust Lifting Simulations with Particles of Distributed Sizes. AIP Conference Proceedings. 631-634.
- (2007). Consequences of particle-particle interaction in a 2D square domain. AIP Conference Proceedings. 639-642.
- (2007). Consequences of particle-particle interaction in a 2-D square domain. AIP Conference Proceedings. 639-642.
- (2007). An Eulerian-Lagrangian model for dense particle clouds. Computers & Fluids. 714-723.
- (2007). A stochastic model for mixing and segregation in slugging fluidized beds. Powder Technology. 118-125.
- (2006). Sol-gel production of zirconia nanoparticles with a new organic precursor. Chemical Engineering Science (CES). 7831-7835.
- (2006). Lifting a wet glass from a table: A microscopic picture. Langmuir. 5666-5672.
- (2006). Investigation of the particle flowpattern and segregation in tapered fluidized bed granulators. Chemical Engineering Science (CES). 4467-4475.
- (2006). Experimental and computational fluid dynamics investigation of the flow in and around once-through swirl tubes. Industrial & Engineering Chemistry Research. 6525-6530.
- (2006). Effect of pressure recovery vanes on the performance of a swirl tube, with emphasis on the flow pattern and separation efficiency. Energy & Fuels. 1691-1697.
- (2006). Danckwerts' law for mean residence time revisited. Chemical Engineering Science (CES). 6213-6217.
- (2006). An investigation of the consequences of primary dust explosions in interconnected vessels. Journal of Hazardous Materials. 752-761.
- (2006). A model for the spray zone in early-stage fluidized bed granulation. AIChE Journal. 2736-2741.
- (2005). Positron emission tomography applied to fluidization engineering. Canadian Journal of Chemical Engineering.
- (2005). PET investigation of a fluidized particle: spatial and temporal resolution and short term motion. Measurement Science and Technology.
- (2005). On suitability of novel fluidised bed technique for separation of metallic powders during commercial powder metallurgical processing. Powder Metallurgy. 199-202.
- (2005). Neutrally boyant tracer in gas cleaning equipment. A case study. Measurement Science and Technology. 2405-2414.
- (2005). Modelling of dust lifting using the Lagrangian approach. International Journal of Multiphase Flow. 1097-1115.
- (2005). Mathematical modelling of dust explosions in interconnected vessels. Nonlinear Analysis. 1087-1096.
- (2005). Experimental study of the vortex end in centrifugal separators: The nature of the vortex end. Chemical Engineering Science (CES). 6919-6928.
- (2005). Dust lifting behind shock waves: comparison of two modelling techniques. Chemical Engineering Science (CES). 5219-5230.
- (2005). Dust explosions in connected vessels: Mathematical modelling. Powder Technology. 108-116.
- (2005). Dispersion of particle pulses in fluidized beds measured by positron emission tomography. AIChE Journal.
- (2004). Separation characteristics of swirl-tube dust separators. AIChE Journal. 87-96.
- (2004). A rheokinetic study of bulk free radical polymerization performed with a helical barrel rheometer. Polymer Engineering and Science. 179-185.
- (2003). On the capacity of continuous powder classification in a gas fluidized bed with horizontal baffles. Powder Technology. 1-15.
- (2003). Dynamic properties of water/alcohol mixtures studied by computer simulation. Journal of Chemical Physics. 7308-7317.
- (2003). Coupling granule properties and granulation rates in high-shear granulation. Powder Technology. 162-168.
- (2002). Rheokinetics of linear polymerization. A literature review. Polymer Engineering and Science. 2383-2392.
- (2002). Flowpattern in Reverse Flow Centrifugal Separators. Powder Technology. 212-222.
- (2002). Deposition of Fine Powder in Horizontal Pipelines and Bends. Chemical Engineering Communications. 849-864.
- (2001). Rheokinetics and the influence of shear rate on the Trommsdorff (gel) effect during free radical polymerization. Polymer Engineering and Science. 595-602.
- (2001). Reducing the gel effect in free radical polymerization. Chemical Engineering Journal. 911-915.
- (2001). Instabilities in free radical polymerization. Nonlinear Analysis: Real world applications. 897-906.
- (2001). Flow in the inlet region in tangential inlet cyclones. Industrial & Engineering Chemistry Research. 5649-5655.
- (2001). Advantages and risks in increasing cyclone separator length. AIChE Journal. 2452-2460.
Vitenskapelig foredrag
- (2023). Visualization of Unsteady Flow in a Multistage Helico-Axial Pump.
- (2022). Commissioning a New Multiphase Pump Visualization Test Rig to Investigate the Internal Flow Field and its Connection with Pump Performance.
- (2021). Multiphase CFD Models of Agglomeration and Deposition in Hydrate Slurries.
- (2019). Synergy from a University / Industry Partnership Leading to Improved Gas/Particulate-Separators.
- (2019). PEPT at the University of Bergen.
- (2018). Turbulence modulation modelling in the CFD simulator FLACS-DustEx.
- (2018). Effect of particle size on burning velocity calculation in FLACS-DustEx.
- (2017). Improved modelling of particle-laden flow in the CFD simulator FLACS-DustEx.
- (2016). Non-invasive studies of multiphase flow in process equipment. Positron emission particle tracking technique.
- (2016). Exact solution for the axial pressure drop in cylindrical isothermal channels with Maxwell slip flow.
- (2016). CFD-PBM modelling of agglomeration and deposition in petroleum industry.
- (2013). Restitution of momentum during interparticle collision affected by liquid bridge.
- (2013). PEPT and CFD investigation of lean-phase pneumatic conveying through a bend.
- (2012). Using a PET camera to track individual phases in process equipment with high temporal and spatial resolutions: Algorithm development.
- (2012). Detecting anomalies in the separation process in a hydrocyclone using a medical PET scanner.
- (2011). Particle-particle agglomeration and use of the hard-sphere model.
- (2011). Particle trajectories in a hydrocyclone measured by PEPT.
- (2011). PEPT: an invaluable tool for 3-D particle tracking and CFD simulation verification in hydrocyclone studies.
- (2011). Order parameters for detection and demarkation of interfaces in hydrate-fluid and ice-fluid systems.
- (2011). Fabrication and cell performance of anode-supported SOFC made of in-house produced NiO-YSZ nano-composite powder.
- (2010). Properties of 3-15 mol% YSZ materials.
- (2010). Particle flow in a hydrocyclone investigated by radioactive particle tracking.
- (2010). Ordering of monosized particles during simulations of a fluid-solid flow under shear.
- (2010). A flexible, cost-effective production method for high-quality nanoparticles.
- (2009). Fully three-dimensional modeling of Solid Oxide Fuel Cells.
- (2009). Computational fluid dynamic model of gas hydrate deposition in a turbulent flow.
- (2008). The Use of Nanoparticles for Solid Oxide Fuel Cell Components.
- (2008). Surface-fluctuations on clathrate hydrate structure I and II slabs in selected environments.
- (2008). Priorities in Material Design for Solid Oxide Fuel Cells -With Emphasis on the Anode and the Electrolyte.
- (2008). Numerical study of an SOFC with direct internal reforming using charge diffusion-based model.
- (2008). NiO nanoparticles for SOFC anodes. Comparison of two synthesis methods.
- (2008). Hydrates in petroleum production-assessment of plug risk. Project HYPERION enters it s third and final year.
- (2007). Simulation of a dust lifting process in a two-dimensional domain with rough walls.
- (2007). Numerical simulation of particle-flow interactions: formation of agglomerates.
- (2007). Numerical simulation of particle-flow interactions: formation of agglomerates.
- (2007). Neutrally buoyant tracer in gas cleaning equipment. A case study.
- (2006). Sol-Gel Production of ZrO2 and YSZ with a New Organic Precursor.
- (2006). Fluid-particle flows in a driven cavity.
- (2006). Direct numerical simulation of particle-fluid flow: The state-of-the-art.
- (2006). 3-D Eulerian-Lagrangian Simulation of Dust Lifting.
- (2005). The physics of cyclones.
- (2004). Mathematical modelling of dust explosions in interconnected vessels.
- (2003). Tracking individual particles in a fluidized bed using a medical PET-Camera.
- (2003). Positron emission tomography applied to fluidization engineering.
- (2003). Brændselcellekursus.
- (2002). Stochastic Model for Fluidization.
- (2002). Positron Emission Tomography (PET) for Fluidization.
- (2002). Observation of Cross-Sectional Non-Uniformity in Fluidized Beds Using Two Different Imaging Techniques.
- (2002). Interparticle Forces for DEM by MD Simulations.
- (2002). Gas Cyclone Separators -- Potential and Limitations.
- (2002). Gas Cyclone Separators -- Potential and Limitations.
- (2002). Feasibility Study of Particle Classification in Fluidized Beds with Internal Baffles.
- (2002). Brenselscelleteknologi.
- (2001). Hvordan levere kompetence til gasindustrien?
- (2001). Determining the best modelling assumptions for cyclones and swirl tubes by CFD and LDA.
- (2001). Coupling granule properties and granulation rates in high-shear granulation.
- (2001). A Stochastic Model for Particle Mixing and Segregation in Fluidized Beds with Baffles.
- (1999). Towards an European Masters in International: the experience of TropEdEurope since 1996.
Anmeldelse
- (2001). Book review, Transport Phenomena by W.J. Beek et al. Chemical Engineering Journal. 337.
Kronikk
- (2005). Fremtidens energi. Bergens Tidende. 1 sider.
Doktorgradsavhandling
- (2018). Experimental and theoretical study of pressure-driven transport of gases in micro and nanopores .
- (2016). Study of the flow in a hydrocyclone using positron emission particle tracking and computational fluid dynamics simulation.
- (2016). A Nonlinear Differential Equation Solver With Potential Application to Pelton Turbines.
- (2015). Interfacial free energies in gas-hydrate/fluid interfaces.
- (2011). Experimental and numerical study of the End of the Vortex phenomenon.
- (2010). Experimental and theoretical study of the flow, aggregation and.
- (2009). Modeling of Transport, Chemical and Electrochemical Processes in Solid Oxide Fuel Cells.
- (2008). Numerical Simulations of Dust Lifting.
- (2007). New Materials for Solid Oxide Fuel Cells Based on Nanoparticles.
- (2006). Experimental Characterization of High-Pressure Natural Gas Scrubbers.
- (2005). Molecular Simulations of Complex Liquids and Confined Systems.
- (2004). Particle Transport in Fluidized Beds; Experiments and Stochastic Models.
Dokumentar
- (2017). Overdrevet "klimagevinst".
- (2017). Full elektrifisering er et blindspor.
- (2017). Full electrification is dead-end, Article in Bergens Tidende, 3. oktober (2017).
- (2017). Exaggerated "climate gains" article in Bergens Tidende.
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
- (2015). Properties of xYSZ nanoparticles and pellets with x varying from 1 to 15%. 4 sider.
- (2015). Design, development and testing of apparatus to study gas diffusion in nanochannels. 4 sider.
- (2011). Stochastic Modeling Techniques in Powder Technology. 46 sider.
Fagartikkel
- (2022). Commissioning a New Multiphase Pump Visualization Test Rig to Investigate the Internal Flow Field and its Connection with Pump Performance. Proceedings of the 38th International Pump Users Symposium.
Procesteknologi
Fysiske transportfænomener