Alexandre Valance

Directeur de Recherche CNRS

A Valloire

Adresse courriel : Alexandre [dot] Valance [at] univ-rennes [dot] fr

Téléphone : +33 223235599

Numéro de bureau : Bât. 11A, bureau 131

Thématiques de recherche

  • Ecoulements granulaires, Ecoulements fluide-particules
  • Transport éolien du sable, transport fuviatile
  • Morphodynamique des dunes de sable
  • Morphogenèse, Dynamique non-linéaire et chaos

Projets en cours

  • ANR EOLE (2022-2026): "Transport éolien de particules cohésives: Du sable à la neige". Partenaires: IRSTEA Grenoble, LTeN Nantes

Projets récents

  • ANR SONO (2017-2021): "Marying coastal Safety objectives with natural development of sand dunes". Partenaires: EPOC, IPGP, ONF.
  • ANR SEGSED (2016-2020): "Segregation in sediment transport". Partenaires: IRSTEA Grenoble, LEGI.

Principales collaborations

Nationales:

  • Rennes: IPR (R. Delanny, L. Oger), INSA (P. Dupont), Géoscience (A. Crave)
  • Nantes: LTEN  (A. Ould El Moctar), Gustave-Eiffel (P. Richard), OSUNA (S. Carpy) 
  • Bordeaux: EPOC (B. Castelle)
  • Paris: IPGP (C. Narteau, A. Mangeney), MSC (S. Courrech Du Pont)
  • Grenoble: ETNA-INRAE (P. Frey, F. Naaim), LEGI (J. Chauchat)
  • Brest: IUEM (N. Le Dantec), ENSTA (F. Floch)

Internationales:

  • Cornell (J. Jenkins, M. Louge)
  • Politecnico Milano (D. Berzi)
  • Bolzano (M. Larcher)

Organisation de conférences

  • Co-organisateur de la seconde édition de la conférence internationale  "Discrete Simulation and Continuum Modeling of Granular Matter", May 20-26, 2023, Masseria Salamina, Puglia, Italy (https://www.salaminagrainworks.com/)
  • Co-organisateur de la 7ème édition de la conférence internationale MARID (Marine and RIver Dune), April 3-5, 2023, Rennes, France (https://marid7.sciencesconf.org/)
  • Co-organisateur de la 1ère édition de la conférence internationale "Discrete Simulation and Continuum Modeling of Granular Matter", May  29-June 3, 2022, Masseria Salamina, Puglia, Italy 
  • Co-organisateur du colloque international "Two-phase continuum models for Geophysical particle-fluid flows", March 14- April 15, 2016, Max Planck Institute, Dresden, Germany
  • Co-organisateur du colloque international "Fluid-mediated Particle transport in Geophysical flows", Sep 23- Dec 20, 2013, KITP, USCB, Santa-Barbara, US

Publications à venir

  • S. Kiki, N. Le Dantec, A. Valance (2023). Two-dimensional subaqueous dunes: scaling laws and saturation length (Preprint).
  • Y. Zhu, A. Valance and R. Delannay (2023). Boundary conditions for granular flows bounded by flat frictional surfaces. (Preprint)
  • G. Minster , F. Floc’h, A. Valance, N. Le Dantec , A. Nicolle, B. Zerr, (2023). On the influence of bed roughness on saltation under inertial regime. Sousmis à ESPL.

Publications Récentes

  • J.B. Besnard, P. Dupont, A. El Moctar, F. Naaim, and A. Valance (2022). Aeolian erosion thresolds for cohesive sand. Journal of Geophysical Research: Earth Surface, 127, https://doi.org/10.1029/2022JF006803
  • J.-L. Ralaiarisoa,, P. Dupont, A. Ould El. Moctar, F. Naaim, A. Valance (2022). Particle impact on a cohesive granular packing. Physical Review E 105, https://doi.org/10.1103/PhysRevE.105.054902
  • M.Y. Louge, A. Valance, J. Xu, A. Ould El Moctar and P. Chasle (2022). Water vapor transport across an arid sand surface non-linear thermal coupling, wind-driven pore advection, subsurface waves, and exchange with the atmospheric boundary layer. Journal of Geophysical Research: Earth Surface,127, https://doi.org/10.1029/2021JF006490
  • A. Valance and D. Berzi (2022). Particle saltation in viscous shearing flows. J. Fluid Mech. (2022), vol. 947, A28, https://doi.org/10.1017/jfm.2022.616
  • P. Richard, A. Valance, R. Delannay, P. Boltenhagen (2022). Granular surface flows confined between flat,frictional walls. Part I: Kinematics. J. Fluid Mech. (2022), vol. 940, A30, https://doi.org/10.1017/jfm.2022.245
  • A. Neveu, R. Delannay, A. Valance, J. Jenkins and M. Larcher. (2022). Particle segregation in inclined high-speed granular flows. JFM, 935, A41,https://doi.org/10.101017/jfm.2022.51
  • O. Roche, S. van den Wildenberg, A. Valance, R. Delannay, A. Mangeney, L. Corna, T. Latchimy (2021). Experimental assessment of the effective friction at the base of granular chute flows on smooth incline. Physical Review E,103, 042905. https://doi.org/10.1103/PhysRevE.103.042905
  • Y. Zhu, R. Delannay, A. Valance (2020). High-speed confined granular flows donw smooth inclines: scaling and wall friction law (2020). Granular Matter 22:82. https://doi.org/10.1007/s10035-020-01053-7
  • P. Richard, R. Artoni, A. Valance, R. Delannay (2020). Influence of lateral confinement on granular flows: comparison between shear‐driven and gravity‐driven flows. Granular Matter 22:81. https://doi.org/10.1007/s10035-020-01057-3
  • J.-L. Ralaiarisoa, J.-B. Besnard, B. Furieri, P. Dupont, A. Ould El. Moctar, F. Naaim, A. Valance (2020). Transition from saltation to collisional regime in wind-blown sand. Physical Review Letters 124, 198501.https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.198501
  • Castelle, B.; Laporte-Fauret, Q.; Marieu, V.; Michalet, R.; Rosebery, D.; Bujan, S.; Lubac, B.; Bernard, J.-B.; Valance, A.; Dupont, P.; Ould El Moctar, A.; Narteau, C. Nature-Based Solution along High-Energy Eroding Sandy Coasts: Preliminary Tests on the Reinstatement of Natural Dynamics in Reprofiled Coastal Dunes. Water 2019, 11, 2518. https://doi.org/10.3390/w11122518
  • M.-C. Ferreira, B. Furieri, B., J.M Santos, J.-L. Harion, Ould El Moctar, A, Valance, P. Dupont et al. (2019). An experimental and numerical study of the aeolian erosion of isolated and successive piles. Environ Fluid Mech. https://doi.org/10.1007/s10652-019-09702-z
  • Bruno Furieri, Maria Clara Caliman, Alexandre Valance et al. (2019). A simple model to estimate emission of wind-blown particles from a granular bed in comparison to wind tunnel experiments. Geomorphology. https://doi.org/10.1016/j.geomorph.2019.03.004
  • Selmani, H., Valance, A., Ould El Moctar, A., Dupont, P., & Zegadi, R. (2018). Aeolian sand transport in out-of-equilibrium regimes. Geophysical Research Letters, 45. https://doi.org/10.1002/2017GL076937
  • J. T. Jenkins & A. Valance (2018). Two-phase continuum theory of wind blown sand. Phys. Rev. Fluid. https://doi.org/10.1103/PhysRevFluids.3.034305
  • S. Belkacem, F, Ould Kaddour and A. Valance (2018). Spreading of a granular droplet under horizontal vibrations. Phys. Rev. E. https://link.aps.org/doi/10.1103/PhysRevE.97.062903

Outils expérimentaux et numériques

Vélocimétrie par suivi de particules dans un écoulement turbulent d'air chargé de grains de sable

 

Simulations numériques discrètes d'un écoulement granulaire granulaire confiné entre 2 parois