1,721,629 research outputs found
Hydrodynamic and Ecological Study of a Sub-Tropical Estuary in Queensland
Full text linkA series of detailed multi-disciplinary field studies was conducted in a small subtropical creek in Eastern Australia. Hydrodynamic and ecological measurements were conducted simultaneously in the river mouth to assess the complexity of the estuarine system, and the interactions between hydraulic engineering, environmental issues, biology and ecology. The results provide unique and original snapshots of subtropical creek system, and the methodology set new standards for comprehensive surveys of small estuaries in sub-tropical zone. A key fea-ture of the field studies was the contrasted outcomes, and the results impact on the selection of "key indicators" (?). Fauna observations showed strong bird and fish activities. But, other re-sults demonstrated on-going pollution
Rumble Sound Generated by a Tidal Bore Event in the Baie du Mont Saint Michel
No full textDescription of data filesMascaretSee01.pdf plot of sound amplitudesSee283.pdf panoramic view of the Pointe du Grouin du Sud and Sélune RiverMascaretSee01.wav DV quality Between 06:48 and 06:52, on 15 October 2008 [miniDV Tape: 00:07:30 to 00:11:30] Tidal bore passage at Pointe du Grouin du Sud : 1'40" to 1'42" of video (06:50) Duration: 3'41"File01.wav From 0'00" to 1'35" - Duration: 1'35"File02.wav From 1'35" to 2'10" - Duration: 0'35"File03.wav From 2'10" to 3'41" - Duration: 1'31"See057.jpg to See218.jpg [CD019] Tidal bore in Baie du Mont Saint Michel and Sée river channel viewed from Pointe du Grouin du Sud around 18:00 to 18:32 on 14 Oct. 2008 - Flood tide Digital Camera Panasonic Lumix FZ20 (1600 dpi, Standard) - Photographs by and Copyright Hubert CHANSON See057.jpg 18:00 about 2km d/s of Pte du Grouin du Sud See078.jpg 18:25 bore in Sélune River channel, Pte du Grouin du Sud See079.jpg 18:25 bores in Sée and Sélune River channels, Pte du Grouin du Sud just upatream of confluence See080.jpg to See085.jpg tidal bore in Sélune River channel just u/s of confluence with Sée River See086.jpg to See092.jpg tidal bore in Sée River channel just u/s of confluence with Sélune River See093.jpg to See096.jpg tidal bores in Sée River channel, bore advancing on sand bank, and Sélune River channel in front of Pte du Grouin du Sud See097.jpg to See105.jpg tidal bores with Ile de Tombelaine in background and seagulls taking off at bore arrival - Bores in front of Pointe du Grouin du Sud See106.jpg to See118.jpg Sée River tidal bore with Ile de Tombelaine in background and seagulls taking off at bore arrival - Bores in front of Pointe du Grouin du Sud See119.jpg to See128.jpg Sée River tidal bore with Mt St Michel in background and seagulls taking off at bore arrival - Bores in front of Pointe du Grouin du Sud See129.jpg to See139.jpg Sée River tidal bore in front of Pointe du Grouin du Sud and turn around the Pointe du Grouin du Sud to enter the Sée River channel See140.jpg to See168.jpg Sée River tidal bore in front of Pointe du Grouin du Sud after turn around the Pointe du Grouin du Sud to enter the Sée River channel bore progressing against a steep slope with standing waves prior to bore arrival See169.jpg to See180.jpg Sée River tidal bore moving u/s away from the Pointe du Grouin du Sud See181.jpg to See191.jpg Sée River tidal bore moving u/s further u/s See193.jpg to See205.jpg Sée River tidal bore moving u/s further u/sMascaret of the Sélune River at Pointe du Grouin du Sud15 October 2008MascaretSee01.wav DV quality Between 06:48 and 06:52, on 15 October 2008 [miniDV Tape: 00:07:30 to 00:11:30] Tidal bore passage at Pointe du Grouin du Sud : 1'40" to 1'42" of video (06:50) Duration: 3'41"File01.wav From 0'00" to 1'35" - Duration: 1'35" File01.wav From 0'45" to 1'35" - Duration: 0'50"File02.wav From 1'35" to 2'10" - Duration: 0'35"File03.wav From 2'10" to 3'41" - Duration: 1'31"Band pass filter: [0-4 kHz]PSD graph : smooth 200FFT analysisDominant frequency Track 01 Track02File01.wav 77 77.8File02.wav 113.7 110.4File03.wav 112.2 81.4Digital Video Camera Canon MV500iE (serial No.: 104516263621)Specifications (Ref. Digital Video Camcorder Instruction Manual Canon MW500/MV500i, 2002)Television system: CCIR standard (625 lines, 50 fields) PAL colour signalVideo recording system: 2 rotary heads, helicoidal scanning DV system (Consumer digital VCR SD system)Audio recording system: PCM digital sound: 16 bit (48 kHz/2 ch), 12 bit (31 kHz/4 ch)Image sensor: 1/6" CCD (charge coupled device) approx. 540,000 pixels (approx. 340,000 effective pixels)Tape format: miniDVTape speed: SP: 3/4ips (18.83 mm/s) - LP: 1/2 ips (12.57 mm/s)Max. recording time: SP: 80 min. - LP: 120 min.Lens: F/1.6-2.9, 18x power zoom, f=2.8-50.4 mm (equivalent to 48-864 mm in 35 mm format)Focusing system: TTL autofocus, manual focusing possibleMinimum focusing distance: 1m (1cm on maximum wide angle)Maximum shutter speed: 1/8,000 sMinimum illumination: 0.1 1x (using the Night program)Recommended illumination: more than 100xFilter diameter: 30.5 mmViewfinder: 0.44 in TFT colour LCD, approx. 113,000 pixelsLCD screen: 2.4 in i measured diagonally, TFT colour, approx. 112,000 pixelsMicrophone: Stereo electret condenser microphoneOperating temperature range: 0 C to 40
Unsteady calibration of a large V-notch weir
No full textThe data collection includes the raw data files, some analysed data files, original photographs, to complement the publications and movies already uploaded at UQ's institutional repository - Unsteady Discharge Calibration of a Large V-Notch Weir (report and publication)
The Hydraulics of Open Channel Flow: An Introduction. Physical Modelling of Hydraulics
Full text linkA physical model is a scaled representation of a hydraulic flow situation. Both the boundary conditions (e.g. channel bed, sidewalls), the upstream flow conditions and the flow field must be scaled in an appropriate manner (Fig. 14.1). Physical hydraulic models are commonly used during design stages to optimize a structure and to ensure a safe operation of the structure. They have an important further role to assist non-engineering people during the `decision-making' process. A hydraulic model may help the decision-makers to visualize and to picture the flow field, before selecting a `suitable' design. In civil engineering applications, a physical hydraulic model is usually a smaller- size representation of the prototype (i.e. the full-scale structure) (e.g. Fig. 14.2). Other applications of model studies (e.g. water treatment plant, flotation column) may require the use of models larger than the prototype. In any case the model is investigated in a laboratory under controlled conditions
The Hydraulics of Open Channel Flow: an Introduction. Sediment Transport Mechanisms 1. Bed-load Transport
Full text linkWhen the bed shear stress exceeds a critical value, sediments are transported in the form of bed-load and suspended load. For bed-load transport, the basic modes of particle motion are rolling motion, sliding motion and saltation motion (Fig. 10.1). In this chapter, formulations to predict the bed load transport rate are presented. Figure 10.2 shows a natural stream subjected to significant bed-load transport
Dam break wave, Tidal bore, In-river tsunami surge: what the hell?
No full textFlood waves resulting from dam breaks have been responsible for numerous losses of life through centuries. Both the 26 December 2004 tsunami and 11 March 2011 Tohoku catastrophes were human tragedies of international significance. An important point is the physical analogy between dam break waves travelling downstream, tidal bores progressing deep inland, in-river tsunami propagating upstream, as well rejection surges in hydropower canals. The leading edge is a hydrodynamic shock, with a marked discontinuity in free-surface elevation and velocity and pressure fields, and a tri-phase flow with three distinct flowing phases, i.e. liquid (water), solid (sediment) and gas (air). Seminal features of bores and surges include a net mass flux, the breaking in shallow waters, and the intense turbulence at the front associated with massive sedimentary processes and air entrainment in the breaking roller. In this keynote talk, physical experiments, numerical CFD modelling and field observations are presented and compared. Current knowledge gaps are discussed. Ultimately it is argued that the 'solitary wave' analogy is not directly relevant to model the unsteady turbulent mixing of in-river tsunami surges, tidal bores and dam break waves
Hydrodynamic, Water Quality and Ecological Study of Eprapah Creek Estuarine Zone: a Multi-Disciplinary, Cross-Institutional Approach
Full text linkA series of detailed multi-disciplinary field studies was conducted in a small subtropical creek : i.e., Eprapah Creek, Victoria Point Queensland. Hydrodynamic and ecological measurements were conducted simultaneously in the river mouth to assess the complexity of the estuarine zone and the interactions between hydraulic engineering, environmental issues, biology and ecology. The results provide unique and original snapshots of a subtropical creek, and the methodology sets new standards for the comprehensive surveys of estuaries in the sub-tropical zone. A key feature of the field studies was the contrasted outcomes, and the results impact on the selection of "key indicators". Fauna observations showed strong bird and fish activities, but other results demonstrated on-going pollution
Research Quality, Publications and Impact in Hydraulic Engineering into the 21st Century. Publish or Perish, Commercial versus Open Access, Internet versus Libraries
Full text linkOne of the main objectives of the first International Junior Researcher and Engineer Workshop on Hydraulic Structures is to provide an opportunity for young researchers and engineers to present their research. But a research project is only completed when it has been published and shared with the community. Referees and peer experts play an important role to control the research quality. While some new electronic tools provide further means to disseminate some research information, the quality and impact of the works remain linked with some thorough expert-review process and the publications in international scientific journals and books. Importantly unethical publishing standards are not acceptable and cheating is despicable
Introduction to Part 1: Basic Principles of Open Channel Flows
Full text linkThe introduction chapter reviews briefly the basic fluid properties and some important results for fluids at rest. Then the concept of open channel flow is defined and some applications are described
Experimental analysis of Froude number effect on air entrainment in hydraulic jumps
No full textA hydraulic jump is characterized by strong energy dissipation and mixing, large-scale turbulence, air entrainment, waves, and spray. Despite recent pertinent studies, the interaction between air bubbles diffusion and momentum transfer is not completely understood. The objective of this paper is to present experimental results from new measurements performed in a rectangular horizontal flume with partially developed inflow conditions. The vertical distributions of the void fraction and the air bubbles count rate were recorded for inflow Froude number Fr1 in the range from 5.2 to 14.3. Rapid detrainment process was observed near the jump toe, whereas the structure of the air diffusion layer was clearly observed over longer distances. These new data were compared with previous data generally collected at lower Froude numbers. The comparison demonstrated that, at a fixed distance from the jump toe, the maximum void fraction Cmax increases with the increasing Fr1. The vertical locations of the maximum void fraction and bubble count rate were consistent with previous studies. Finally, an empirical correlation between the upper boundary of the air diffusion layer and the distance from the impingement point was derived
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