NHESS Natural Hazards and Earth System Sciences NHESS Nat. Hazards Earth Syst. Sci. 1684-9981 Copernicus Publications Göttingen, Germany 10.5194/nhess-2-181-2002 An experimental study of particle-driven gravity currents on steep slopes with entrainment of particles Rastello M. 1 Ancey C. 1 Ousset F. 1 Magnard R. 1 Hopfinger E. J. 2 Cemagref, u.r. etna, 2 rue de la papeterie, BP 76, F-38402 Saint Martin d’Hères, France Legi, 1025 rue de la Piscine, BP 53, F-38041 Grenoble Cedex, France 31 12 2002 2 3/4 181 185 Copyright: © 2002 M. Rastello et al. 2002 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://nhess.copernicus.org/articles/2/181/2002/nhess-2-181-2002.html The full text article is available as a PDF file from https://nhess.copernicus.org/articles/2/181/2002/nhess-2-181-2002.pdf

Results of laboratory experiments are presented in which a finite suspension of sawdust particles was released instantaneously into a rectangular channel immersed in a water tank. Two kinds of gravity currents were studied: currents with or without entrainment of particles from the bed. Experiments were repeated for two slopes: 30° and 45°. We observed that the velocity of the front was significantly in-creased as particle entrainment occurred. In addition, our experiments showed that the front kept a quasi-constant velocity for both runs. This might suggest that the flow regime corresponded to the "slumping regime" or "adjustment phase" described earlier by Huppert and Simpson (1980).