@article{fdi:010046764,
  title = {{E}xperimental study of gas-fluidized granular flows with implications for pyroclastic flow emplacement},
  author = {{R}oche, {O}livier and {G}ilbertson, {M}.{A}. and {P}hillips, {J}.{C}. and {S}parks, {R}.{S}.{J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{E}xperiments have been carried out on initially gas-aerated and gas-fluidized granular flows propagating into a horizontal channel. {A}fter lateral acceleration following release of the originally fluidized bed, two contrasting flow behaviors were observed, which reflected the degree of initial fluidization and the grain size. {I}nitial fluidization disrupts the interparticle contact network, which controls internal friction of the static bed. {T}he flow regime then depends on the timescale needed to reestablish a strong contact network, and this time increases as the grain size decreases. {I}nitially aerated and fluidized flows of coarse particles (>approximate to100 mum) and initially aerated flows of fine particles (<&{AP}; 100 μm) behave as their nonfluidized counterparts and they propagate as a wedge, with decelerating velocities so that the front position increases as the &{SIM};0.8 power of time. {I}n contrast, initially fluidized flows of fine particles propagate for most of their duration at constant thickness and frontal velocity in a similar fashion to the slumping regime of buoyancy-driven gravity currents of {N}ewtonian fluids. {W}e have determined a {F}roude number {F}r for such flows of &{AP};2.6 consistent with published data from experimental and theoretical investigations on inviscid fluids. {T}his implies that internal particle friction can be neglected in describing the dynamics of initially fluidized, concentrated fine granular flows. {H}owever, all flows are characterized by a short, final stopping phase whose timescale gives an estimate of the kinetics required to reestablish a strong contact network and form a static deposit. {T}hese results suggest that fines-rich pyroclastic flows may propagate as inviscid fluids for most of their emplacement.},
  keywords = {volcanology ; explosive volcanism ; pyroclastic flows ; fluidization ; experiments ; granular flows ; fluid gravity currents},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch {S}olid {E}arth},
  volume = {109},
  numero = {{B}10},
  pages = {{B}10201 [ {NIL}_20--{NIL}_33]},
  ISSN = {0148-0227},
  year = {2004},
  DOI = {10.1029/2003{JB}002916},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046764},
}