Air–water flows

Journal of Hydraulic Research, vol. 62, pp. 319–339

Abstract

High Froude-number open-channel flows can entrain significant volumes of air, a phenomenon that occurs continuously in spillways, in free-falling jets and in hydraulic jumps, or as localized events, notably at the toe of hydraulic jumps or in plunging jets. Within these flows, turbulence generates millions of bubbles and droplets as well as highly distorted wavy air–water interfaces. This phenomenon is crucial from a design perspective, as it influences the behaviour of high-velocity flows, potentially impairing the safety of dam operations. This review examines recent scientific and engineering progress, highlighting foundational studies and emerging developments. Notable advances have been achieved in the past decades through improved sampling of flows and the development of physics-based models. Current challenges are also identified for instrumentation, numerical modelling and (up)scaling that hinder the formulation of fundamental theories, which are instrumental for improving predictive models, able to offer robust support for the design of large hydraulic structures at prototype scale.

Authors 7

1. Daniel Valero corresponding

   Imperial College London

   Affiliation as printed

   Department of Civil and Environmental Engineering, Imperial College London, London, UK

2. Stefan Felder

   UNSW Sydney

   Affiliation as printed

   Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, Sydney, NSW, Australia

3. Matthias Kramer

   UNSW Canberra

   Affiliation as printed

   School of Engineering and Technology (SET), UNSW Canberra, Canberra, Australia

4. Hang Wang

   Sichuan University · State Key Laboratory of Hydraulics and Mountain River Engineering

   Affiliation as printed

   State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, PR China

5. José M. Carrillo

   Universidad Politécnica de Cartagena

   Affiliation as printed

   Hydraulic Engineering Area, Universidad Politécnica de Cartagena, Cartagena, Spain

6. Michael Pfister

   School of Engineering and Architecture of Fribourg

   Affiliation as printed

   Filière de génie civil, Haute école d'ingénierie et d'architecture de Fribourg, Fribourg, Switzerland

7. Daniel B. Bung Aachen Hydraulic Engineering Section (HES)

   FH Aachen

   Affiliation as printed

   Hydraulic Engineering Section (HES), FH Aachen, University of Applied Sciences, Aachen, Germany