A hydraulic jump is a phenomenon in the science of hydraulics which is frequently observed in open channel flow such as rivers and spillways. When liquid at high velocity discharges into a zone of lower velocity, a rather abrupt rise occurs in the liquid surface. The rapidly flowing liquid is abruptly slowed and increases in height, converting some of the flow's initial kinetic energy into an increase in potential energy, with some energy irreversibly lost through turbulence to heat. In an open channel flow, this manifests as the fast flow rapidly slowing and piling up on top of itself similar to how a shockwave forms.
A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon is a structure on or around artificial and natural barriers to facilitate diadromous fishes' natural migration as well as movements of potamodromous species. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps into the waters on the other side. The velocity of water falling over the steps has to be great enough to attract the fish to the ladder, but it cannot be so great that it washes fish back downstream or exhausts them to the point of inability to continue their journey upriver.
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.
A tidal bore, often simply given as bore in context, is a tidal phenomenon in which the leading edge of the incoming tide forms a wave of water that travels up a river or narrow bay, reversing the direction of the river or bay's current. It is a strong tide that pushes up the river, against the current.
A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure that water does not damage parts of the structure not designed to convey water.
A culvert is a structure that channels water past an obstacle or to a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. In the United Kingdom, the word can also be used for a longer artificially buried watercourse.
Hunter Rouse was a hydraulician known for his research on the mechanics of fluid turbulence.
Jean-Baptiste Charles Joseph Bélanger was a French applied mathematician who worked in the areas of hydraulics and hydrodynamics. He was a professor at the École Centrale des Arts et Manufactures, École Polytechnique and École des Ponts et Chaussées in France. In hydraulic engineering, he is often credited improperly for the application of the momentum principle to a hydraulic jump in a rectangular open channel in 1828. His true contribution in 1828 was the development of the backwater equation for gradually varied flows in open channels and the application of the momentum principle to the hydraulic jump flow in 1838.
In hydraulic engineering, a nappe is a sheet or curtain of water that flows over a weir or dam. The upper and lower water surface have well-defined characteristics that are created by the crest of a dam or weir. Both structures have different features that characterize how a nappe might flow through or over impervious concrete structures. Hydraulic engineers distinguish these two water structures in characterizing and calculating the formation of a nappe. Engineers account for the bathymetry of standing bodies or moving bodies of water. An appropriate crest is built for the dam or weir so that dam failure is not caused by nappe vibration or air cavitation from free-overall structures.
The Chézy formula is an semi-empirical resistance equation which estimates mean flow velocity in open channel conduits. The relationship was realized and developed in 1768 by French physicist and engineer Antoine de Chézy (1718–1798) while designing Paris's water canal system. Chézy discovered a similarity parameter that could be used for estimating flow characteristics in one channel based on the measurements of another. The Chézy formula relates the flow of water through an open channel with the channel's dimensions and slope. The Chézy equation is a pioneering formula in the field of fluid mechanics and was expanded and modified by Irish Engineer Robert Manning in 1889. Manning's modifications to the Chézy formula allowed the entire similarity parameter to be calculated by channel characteristics rather than by experimental measurements. Today, the Chézy and Manning equations continue to accurately estimate open channel fluid flow and are standard formulas in all fields that relate to fluid mechanics and hydraulics, including physics, mechanical engineering and civil engineering.
Shear velocity, also called friction velocity, is a form by which a shear stress may be re-written in units of velocity. It is useful as a method in fluid mechanics to compare true velocities, such as the velocity of a flow in a stream, to a velocity that relates shear between layers of flow.
Acoustic Doppler velocimetry (ADV) is designed to record instantaneous velocity components at a single-point with a relatively high frequency. Measurements are performed by measuring the velocity of particles in a remote sampling volume based upon the Doppler shift effect.
The moving particle semi-implicit (MPS) method is a computational method for the simulation of incompressible free surface flows. It is a macroscopic, deterministic particle method developed by Koshizuka and Oka (1996).
A stepped spillway is a spillway with steps on the spillway chute to assist in the dissipation of the kinetic energy of the descending water. This eliminates or reduces the need for an additional energy dissipator, such as a body of water, at the end of the spillway downstream.
The Journal of Hydraulic Engineering, formerly the Journal of the Hydraulics Division (1956–1982), is a peer-reviewed scientific journal published by the American Society of Civil Engineers. Topics range from flows in closed conduits to free-surface flows to environmental fluid dynamics. Topics include transport processes involving fluids such as sediment and contaminant transport, and heat and gas transfers. Emphasis is placed on the presentation of concepts, methods, techniques, and results that advance knowledge and/or are suitable for general application in the hydraulic engineering profession.
Subhasish Dey is a hydraulician and educator. He is known for his research on the hydrodynamics and acclaimed for his contributions in developing theories and solution methodologies of various problems on hydrodynamics, turbulence, boundary layer, sediment transport and open channel flow. He is currently a distinguished professor of Indian Institute of Technology Jodhpur (2023–). Before, he worked as a professor of the department of civil engineering, Indian Institute of Technology Kharagpur (1998–2023), where he served as the head of the department during 2013–15 and held the position of Brahmaputra Chair Professor during 2009–14 and 2015. He also held the adjunct professor position in the Physics and Applied Mathematics Unit at Indian Statistical Institute Kolkata during 2014–19. Besides he has been named a distinguished visiting professor at the Tsinghua University in Beijing, China.
In hydraulic engineering, air bubble entrainment is defined as the entrapment of air bubbles and pockets that are advected within the turbulent flow. The entrainment of air packets can be localised or continuous along the air–water interface. Examples of localised aeration include air entrainment by plunging water jet and at hydraulic jump. Bubbles are entrained locally at the intersection of the impinging jet with the surrounding waters. The intersecting perimeter is a singularity in terms of both air entrainment and momentum exchange, and the air is entrapped at the discontinuity between the impinging jet flow and the receiving pool of water. Interfacial aeration is defined as the air entrainment process along an air–water interface, usually parallel to the flow direction.
Forrest Merton Holly Jr. was an American civil engineering professor, an hydraulician and the co-inventor of the Holly-Preissmann scheme for simulating transport of contaminants and suspended sediments in rivers. Holly was an expert in computational hydraulics, dispersion in natural waters, alluvial river processes, urban hydraulics, thermal transport in rivers, and irrigation control systems with interest the solution of practical river engineering problems..
Willi H. Hager is a Swiss civil engineer and Professor at the ETH Zurich, Department of Civil, Environmental and Geomatic Engineering, known for his work on hydraulics.
Joseph Hun-wei Lee is a Chinese civil engineer, currently serving as President of the Macau University of Science and Technology.
