Boussinesq and non-Boussinesq gravity currents propagating on unbounded uniform slopes in the deceleration phase

Albert Dai,Yu-Lin Huang

doi:10.1017/jfm.2021.300

Abstract

Highlights

Gravity currents are flows driven by density differences and occur ubiquitously in natural and man-made environments (Simpson 1997; Ungarish 2009)
For the planar gravity currents propagating on a favourable slope, Beghin et al (1981) observed that planar gravity currents may go through an acceleration phase followed by a deceleration phase, and developed the thermal theory to describe the two phases of motion
Dai (2013a, 2014) further categorised the deceleration phase of the planar gravity currents propagating on a favourable slope into an early stage, where the buoyancy force is in balance with the inertia force, and a late stage, where the buoyancy force is in balance with the viscous force

Summary

Introduction

Gravity currents are flows driven by density differences and occur ubiquitously in natural and man-made environments (Simpson 1997; Ungarish 2009). Compared with the planar gravity currents, the gravity currents propagating on a horizontal or sloping boundary without being bounded in the spanwise direction have received less attention (Cantero, Balachandar & Garcia 2007; La Rocca et al 2008; Sahuri et al 2015; Dai & Wu 2016; Inghilesi et al 2018). This configuration is more similar to that of turbidity currents down a continental shelf and powder snow avalanches (Hopfinger 1983; Ouillon, Meiburg & Sutherland 2019).

Theoretical background

Experimental set-up

Results

Conclusions