[1] T J Wilson, C R Pfeifer, N Meysingier, D J Durian, Granular discharge rate for submerged hoppers, Pap. Phys. 6, 060009 (2014).
http://dx.doi.org//10.4279/PIP.060009
[2] J E Hilton, P W Cleary, Granular flow during hopper discharge, Phys. Rev. E 84, 011307 (2011).
http://dx.doi.org/10.1103/PhysRevE.84.011307
[3] L Staron, P-Y Lagree, S Popinet, The granular silo as a continuum plastic flow: The hour-glass vs the clepsydra, Phys. Fluids 24, 113303 (2012).
http://dx.doi.org/10.1063/1.4757390
[4] H A Janssen, Versuche uber getreidedruck in silozelen, Zeitschr. Vereines Deutsch. Ing. 39, 1045 (1895).
[5] L Rondon, O Pouliquen, P Aussillous, Granular collapse in a fluid: Role of the initial volume fraction, Phys. Fluids 23, 073301 (2011).
http://dx.doi.org/10.1063/1.3594200