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I am an applied mathematician and fluid dynamicist, and I am interested in using mathematics to model and understand physical processes in the world around us. I am currently a Lecturer in Applied Mathematics at University College London.

Research interests

If you are interested in studying for a PhD or holding a postdoctoral position working with me, or if you are an undergraduate interested in a summer project, please get in touch. Research areas in which I have worked and topics of current interest include:

  • Non-Newtonian fluid mechanics and dynamics of 'structured' fluids: geophysical applications (mudslides, magmatic systems, mud volcanism); industrial applications (mine tailings, batch processing, cleaning)

  • Viscoplasticity: channel flow; clogging and jamming; displacement flows; viscoplastic boundary layers; locomotion through viscoplastic fluids

  • Poro-elasticity and flow through/of deformable media: applications in geophysics (subsidence, sub-glacial till, liquefaction) and industry (pulp and paper)

  • Thixotropy, liquefaction, two-phase flow

  • Convection in porous media: impact of heterogeneity; plume dynamics; dissolution and CO2 sequestration; astrophysical convection and internal heat

  • Mixing in porous media; viscous fingering

  • Double-diffusion in geological settings: mid-ocean ridge dynamics, porous media, magma chambers

Publications

  1. Daneshi, M., MacKenzie,J., Balmforth,N.J., Martinez,D.M. and Hewitt, D.R. Obstructed viscoplastic flow in a Hele–Shaw cell, Physical Review Fluids 2020 5 (013301) [pdf]

  2. Warburton, K.L.P., Hewitt, D.R. and Neufeld, J.A. The elastic Landau-Levich problem on a slope, Journal of Fluid Mechanics, 2020 883 (A40) [pdf]

  3. Hewitt, D.R., Peng, G.G., and Lister, J.R. Buoyancy-driven plumes in a layered porous medium, Journal of Fluid Mechanics, 2020 883 (A37) [pdf]

  4. Supekar, R., Hewitt, D.R. and Balmforth, N.J. Translating and squirming cylinders in a viscoplastic fluid, Journal of Fluid Mechanics, 2020 882 (A11) [pdf] (see also Front-cover picture of journal)

  5. Eaves, T.S., Paterson, D.T., Hewitt, D.R., Balmforth, N.J. and Martinez, D.M. Dewatering saturated, networked suspensions with a screw press, Journal of Engineering Mathematics, 2019 doi:10.1007/s10665-019-10029-3 [pdf]

  6. Paterson, D.T., Eaves, T.S., Hewitt, D.R., Balmforth, N.J. and Martinez, D.M. Flow-driven compaction of a fibrous porous medium, Physical Review Fluids, 2019 4 (074306) [pdf]

  7. Nijjer, J.S., Hewitt, D.R., and Neufeld, J.A. Stable and unstable miscible displacements in layered porous media, Journal of Fluid Mechanics, 2019 869 (468-499) [pdf]

  8. Hewitt, D.R., and Balmforth, N.J. Viscoplastic slender-body theory, Journal of Fluid Mechanics, 2018 856 (870-897) [pdf] (see also 'Focus on Fluids' review article Dropping slender-body theory into the mud by Saverio Spagnolie)

  9. Hewitt, D.R., Chini, G.P. and Neufeld, J.A. The influence of a poroelastic till on rapid subglacial flooding and cavity formation, Journal of Fluid Mechanics, 2018 855 (1170-1207) [pdf]

  10. Nijjer, J.S., Hewitt, D.R., and Neufeld, J.A. The dynamics of miscible viscous fingering from onset to shutdown, Journal of Fluid Mechanics, 2018 837 (520-545) [pdf]

  11. Hewitt, D.R., and Lister, J.R., Stability of columnar convection in a three-dimenional porous medium, Journal of Fluid Mechanics, 2017 829 (89-111) [pdf]

  12. Hewitt, D.R., and Balmforth, N.J., Taylor's swimming sheet in a yield stress fluid, Journal of Fluid Mechanics, 2017 828 (33-56) [pdf]

  13. Kvick, M., Martinez, D.M., Hewitt, D.R., and Balmforth, N.J., Imbibition with swelling: Capillary rise in thin deformable porous media, Physical Review Fluids, 2017 2 (074001) [pdf]

  14. Balmforth, N.J., Craster, R.V., Hewitt, D.R., Hormozi, S., and Maleki, A., Viscoplastic boundary layers, Journal of Fluid Mechanics, 2017 813 (929-954) [pdf]

  15. Liu, Y., Balmforth, N.J., Hormozi, S. and Hewitt, D.R., Two-dimensional viscoplastic dambreaks, Journal of Non-Newtonian Fluid Mechanics, 2016 238 (65-79) [pdf]

  16. Hewitt, D.R., Paterson, D.T., Balmforth, N.J., and Martinez, D.M. Dewatering of fibre suspensions by pressure filtration, Physics of Fluids, 2016 28 (063304). [pdf]

  17. Hewitt, D.R., Nijjer, J.S., Neufeld, J.A., and Worster, M.G. Flow-induced compaction of a deformable porous medium, Physical Review E, 2016 93, 023116 [pdf]

  18. Hewitt, D.R., Balmforth, N.J., Dasani, M., and Martinez, D.M. Obstructed and channelized viscoplastic flow in a Hele-Shaw cell, Journal of Fluid Mechanics, 2016 790 (173-204) [pdf]

  19. Hewitt, D.R., Neufeld, J.A., and Balmforth, N.J. Shallow, gravity-driven flow in a poro-elastic layer, Journal of Fluid Mechanics, 2015 778 (335-360) [pdf]

  20. Hewitt, D.R., Neufeld, J.A., and Lister, J.R. High Rayleigh number convection in a porous medium containing a thin low-permeability layer, Journal of Fluid Mechanics, 2014 756 (844-869) [pdf]

  21. Hewitt, D.R., Neufeld, J.A., and Lister, J.R. High Rayleigh number convection in a three-dimensional porous medium, Journal of Fluid Mechanics, 2014 748 (879-895) [pdf]

  22. Hewitt, D.R., Neufeld, J.A., and Lister, J.R. Stability of columnar convection in a porous medium, Journal of Fluid Mechanics, 2013 737 (205-231) [pdf]

  23. Hewitt, D.R., and Balmforth, N.J. Thixotropic gravity currents, Journal of Fluid Mechanics, 2013 727 (56-82) [pdf]

  24. Hewitt, D.R., Neufeld, J.A., and Lister, J.R. Convective shutdown in a porous medium at high Rayleigh number, Journal of Fluid Mechanics, 2013 719 (551-586) [pdf] (see also 'Focus on Fluids' review article by David Pritchard, and Front-cover picture)

  25. Hewitt, D.R., Neufeld, J.A., and Lister, J.R. Ultimate regime of high Rayleigh number convection in a porous medium, Physical Review Letters, 2012 108 (224503) [pdf]

Previously

From 2015 until 2019, I was a Research Fellow and, latterly, Tutor, at Gonville and Caius College, University of Cambridge. Prior to that, I was a Killam Postdoctoral Research Fellow in the Department of Mathematics at the University of British Columbia, Vancouver (2014-2015).

I hold a Ph.D. in Applied Mathematics from the University of Cambridge; my PhD thesis, entitled 'High Rayleigh number Convection in a Porous Medium', can be found here.

My C.V. can be found here.

Teaching: old website for MATH256, taught at UBC, can be found here.

Contacts

email: d.hewitt 'at' ucl.ac.uk
Office: Room 700, 25 Gordon Street
Address: Department of Mathematics, University College London,
25 Gordon Street, Bloomsbury, London WC1H 0AY
Telephone: ??