Turbulent flows on highly rough beds, such as those occurring in natural watercourses, represent alongstanding and fascinating problem of hydraulics, motivating in the past few decades huge researchon new models of turbulence. In this work, laboratory experiments are presented on a stream flowingon a heterogeneous pebble bed with varying slope. The analysis of the flow speed puts in evidencea clear inertial range, where the Kolmogorov 4/5-law for the streamwise velocity spatial incrementsholds. The law is used for a systematic estimation of the turbulent kinetic energy dissipation rate ,here measured for three different bed slopes and hence for three different shear Reynolds numbers. Theexperiments presented here suggest that small scale turbulence has properties similar to the classicalpicture of homogeneous universal turbulence invoked by the Kolmogorov theory.

Turbulent energy dissipation rate in a tilting flume with a highly rough bed

Coscarella F;SERVIDIO, SERGIO;Ferraro D;Carbone V;GAUDIO, Roberto
2017

Abstract

Turbulent flows on highly rough beds, such as those occurring in natural watercourses, represent alongstanding and fascinating problem of hydraulics, motivating in the past few decades huge researchon new models of turbulence. In this work, laboratory experiments are presented on a stream flowingon a heterogeneous pebble bed with varying slope. The analysis of the flow speed puts in evidencea clear inertial range, where the Kolmogorov 4/5-law for the streamwise velocity spatial incrementsholds. The law is used for a systematic estimation of the turbulent kinetic energy dissipation rate ,here measured for three different bed slopes and hence for three different shear Reynolds numbers. Theexperiments presented here suggest that small scale turbulence has properties similar to the classicalpicture of homogeneous universal turbulence invoked by the Kolmogorov theory.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11770/136695
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 19
social impact