Transport Phenomena

The Transport Phenomena group studies the transport of mass, momentum and heat in physical and (electro)chemical processes related to advanced materials processing, energy conversion and storage, and health. Our main interest is in transport around (solid-fluid, liquid-gas, liquid-liquid, membrane-fluid and electrically charged) interfaces, which we wish to understand, control and enhance.

We enjoy performing fundamental research to gain a deep understanding of the underlying phenomena, while at the same time we find it important to apply our knowledge to real-life applications.We use both theoretical and computational models, and non-intrusive experiments based on laser and X-ray techniques.

TP Seminar/Lunch Schedule

17.10.2019  -  Sweder Steensma, JonasHamann and Jesper Fennema
24.10.2019  -  Stef Booij and Allessandro Endrighi
31.11.2019  -  Amir Assadbeigi




October 2019:
PhD student Maulik Shah (PPE/TP) recently published a paper “Thermal fluctuations in capillary thinning of thin liquid films” in Journal of Fluid Mechanics.

Thinning of non-planar liquid films, for instance between two bubbles in a foam, is determined by the interplay between stabilizing surface tension forces and destabilizing van der Waals forces, as well as drainage due to curvature differences. Moreover, thermal fluctuations have been shown to influence the thinning dynamics. Maulik’s paper explores the influence of thermal fluctuations on the thinning dynamics. For strong drainage, he finds that the film ruptures due to the formation of a local dimple. For weak drainage the film ruptures at a random location due to the spontaneous growth of fluctuations originating from thermal fluctuations.

PhD student Sid Mukherjee recently published a paper “Droplet-turbulence interactions and quasi-equilibrium dynamics in turbulent emulsions” in Journal of Fluid Mechanics.
In this paper Sid performs direct numerical simulations of emulsions in homogeneous isotropic turbulence using the lattice-Boltzmann method. He demonstrates that droplet breakup extracts kinetic energy from the larger scales while injecting energy into the smaller scales, with approximately the famous Hinze scale separating the two effects. A generalization of that Hinze scale is proposed, which applies both to dense and dilute suspensions. Sid shows, for the first time, that turbulent emulsions evolve into quasi-equilibrium cycles of alternating coalescence and breakup dominated processes, and that their dynamics resemble limit cycles with a time delay. He hopes that this paper brings to attention the avenue of considering the details of resolved simulations, and that this will help the understanding of the phenomena at different levels.

Dr. Valeria Garbin will joined TP as an associate Professor. 
She has been teaching courses, lab courses and projects on Fluid Mechanics, Colloid and Interface Science, Plant Design and Multiphase Flow at Imperial College for the last 7 years. 

September 2019: 
Kevin van As' paper on speckle imaging of blood flow is PRE's editor's choice.
Kevin van As’ paper "Laser speckle imaging of flowing blood: A numerical study" has been selected by the editors of Physical Review E to be an Editors' Suggestion, indicating that the editors and referees of PRE find this paper of particular interest, importance, and clarity. Laser speckle imaging can be used to study dynamic processes in turbid media, such as blood flow embedded in tissue, but it is difficult to obtain quantitative information from this technique. This paper presents a computational model for simulating the imaging process, which will be useful to further develop it as a quantitative tool for biomedical and other applications.

Dr. David Vermaas has received a 1.5 M€ ERC starting grant for his reserach proposal "Enhanced Mass Transport in Electrochemical Systems for Renewable Fuels and Clean Water".
To meet the growing demand of energy and clean water for the next decades, we can use the increasing supply of harvested solar and wind energy to synthesize fuels and clean water via electrochemical methods. Among the technical aspects to make electrochemical routes competitive, a boost in current density at large-scale deployment is required. This can only be established via breaking three limits in mass transport, at three different scales: 1) the diffusion boundary layer (microscale), 2) gas bubble interference (mm-scale) and 3) concentration gradients in the bulk of flow compartments. With a group of 3 new PhD students and a postdoc, David's research will address these three mass transport limitations in a multiscale approach.




Recent Publications

S. Mukherjee, A. Safdari, O. Shardt, S. Kenjeres, H. E. A. van den Akker, Droplet-turbulence interactions and quasi-equilibrium dynamics in turbulent emulsions, J. Fluid. Mech., 2019, 878, 221-276

M. S. Shah, V. van Steijn, C. R. Kleijn, M. T. Kreutzer, Thermal fluctuations in capillary thinning of thin liquid films, J. Fluid. Mech., 2019, 876, 1090-1107 

K. van As, J.. Boterman, C. R. Kleijn, S. Kenjeres, N. Bhattacharya, Laser speckle imaging of flowing blood: A numerical study, Phys. Rev. E, 2019, 100(3), 033317

V. Garbin, Collapse mechanisms and extreme deformation of particle-laden interfaces, Curr. Opin. Colloid Interface Sci., 2019, 39, 202-211

B. Dollet, P. Marmottant, V. Garbin, Bubble Dynamics in Soft and Biological Matter, Annu. Rev. Fluid Mech, 2019, 51, 331-355

I. Ataei-Dadavia, N. Rounaghi, M. Chakkingal, S. Kenjeres, C. R. Kleijn, M. J. Tummers, An experimental study of flow and heat transfer in a differentially side heated cavity filled with coarse porous mediaInt. J. Heat Mass Transf.2019, 143,  118591

W. Jin, J. R. van Ommen, C. R. Kleijn, Moving reaction fronts in fractal nanoparticle agglomeratesChem. Eng. Sci2019206,180-186

S. Kenjeres, J. P. van der Krieke, C. Li, Endothelium resolving simulations of wall shear-stress dependent mass transfer of LDL in diseased coronary arteries, Comp. Biol. and Med., 114, 2019, 103453

K.C.J. Schutte, L. M. Portela, A. Werda, R. A. W. M. Henkes, Formation and break-up of rigid agglomerates in turbulent channel and pipe flows, J. Fluid Mech2018, 857, 539-561

C. Haringa, C. de Jong, D. A. Hoang, L. M. Portela, C. R. Kleijn, M. T. Kreutzer, V. van Steijn, Breakup of elongated droplets in microfluidic T-junctions, Phys. Rev. Fluids, 2019, 4, 024203 

W. A. Smith, T. Burdyny, D. A. Vermaas, H. Geerlings, Pathways to Industrial-Scale Fuel Out of Thin Air from CO2 Electrolysis, Joule, 20193(8), 1822-1834