This work deals with the mathematical and numerical modelling of one dimensional instantaneous dam break flow over a movable bed of cohesionless solid grains. The sudden removal of the dam causes intense sediment transport phenomena and a localised scour at the dam site. The adopted four equation mathematical model has a quite general structure, considered to be valid both for sediment transport and debris flow mechanisms. Only the scheme for the extraction-deposition mechanism of the solid material from/onto the bottom and the evaluation of the friction slope is different in the two cases. The comparison of numerical results with experimental laboratory results indicates advantages and disadvantages encountered by considering the sediment flux from/to the bottom as a typical intense sediment transport phenomenon or as a typical immature debris flow phenomenon.
Numerical simulation of dam break flow on granular bed: intense sediment transport vs. debris-flow modeling
VALIANI, Alessandro;CALEFFI, Valerio
2003
Abstract
This work deals with the mathematical and numerical modelling of one dimensional instantaneous dam break flow over a movable bed of cohesionless solid grains. The sudden removal of the dam causes intense sediment transport phenomena and a localised scour at the dam site. The adopted four equation mathematical model has a quite general structure, considered to be valid both for sediment transport and debris flow mechanisms. Only the scheme for the extraction-deposition mechanism of the solid material from/onto the bottom and the evaluation of the friction slope is different in the two cases. The comparison of numerical results with experimental laboratory results indicates advantages and disadvantages encountered by considering the sediment flux from/to the bottom as a typical intense sediment transport phenomenon or as a typical immature debris flow phenomenon.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
