Home » RESEARCH » Granular Flow

Granular Flow

It is known, since 1895, that the pressure at the bottom of a silo does not depend on the height of the column of grains, as long as the height is above twice the silo diameter. In the 60s, it was also established that the flow rate during the discharge of a silo is constant irrespective of the column height. These two findings seem to be connected to each other and many have assumed the first phenomenon was the cause for the second. In cooperation with Grupo de Medios Porosos (Universidad de Buenos Aires) and the Granular Laboratory of Ecole Normal Superieure de Lyon, we have designed a new experiment that shows that pressure and flow rate are not correlated and both can be tunned independently.


  1. Physical Review E 85, 1. 021303 (2012): C. Perge, M. A. Aguirre, P. A. Gago, L. A. Pugnaloni, D. Le Tourneau, J.-C. Géminard, Evolution of pressure profiles during the discharge of a silo
  2. Physical Review E 83, 061305 (2011): M. A. Aguirre, J. G. Grande, A. Calvo, L. A. Pugnaloni, J.- C. Geminard, Granular flow through an aperture: Pressure and flow rate are independent
  3. Physical Review Letters 104, 238002_1- 238002_4 (2010): M.A. Aguirre, J.G. Grande, A. Calvo, L.A. Pugnaloni, J-C. Geminard, Pressure independence of granular flow through an aperture