Natural Hazards Modeling: From Runoff to Hyperconcentrated Flows – Roll Waves Generation

Ferreira, Fabiana de Oliveira; Maciel, Geraldo de Freitas; Fiorot, Guilherme Henrique; Cunha, Evandro Fernandes da

doi:10.7763/ijet.2015.v7.792

Cited by 4 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several researchers, among them Ishihara et al (1954), Benjamin (1957), Yih (1963Yih ( , 1977 and Ferreira et al (2015) indicated that for laminar flow down an inclined plane, the roll waves tended to form when the Froude number was greater than 0.58. Julien and Hartley (1986) found that roll wave was observed in laminar, subcritical flow at a Froude number as low as 0.74.…”

Section: Introductionmentioning

confidence: 98%

Response of roll wave to suspended load and hydraulics of overland flow on steep slope

Zhao

Gao

Zhang

et al. 2015

CATENA

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 98%

Response of roll wave to suspended load and hydraulics of overland flow on steep slope

Zhao

Gao

Zhang

et al. 2015

CATENA

View full text Add to dashboard Cite

“…Researchers have sought a better understanding of the phenomenon, dealing with the problem globally, whether through proposals for new mathematical models, new numerical simulation techniques [7][8][9][10] or modern experimental techniques (non-intrusive) for measurement of these waves.…”

Section: Introductionmentioning

confidence: 99%

Non-intrusive techniques to measure roll waves level evolving in a flume

et al. 2018

View full text Add to dashboard Cite

An open-channel experimental set-up is presented in this paper as a tool for examining the presence of instabilities on free-surfaces flows of non-Newtonian fluid. When these flows occur in favorable conditions of inclination, discharge and rheological properties, the propagation of instabilities can evolve into a specific type of wave, known as roll waves. The experimental apparatus developed allows study of stabilized roll waves in many scenarios for non-Newtonian rheology fluids, thereby constituting a highly useful tool for the understanding and control of roll waves. The test fluid used in the experiments was carbopol gel which is rheometrically representative of the muddy material from natural disasters, such as mudflows. Two non-intrusive level measurement systems are proposed (ultrasonic transducer and laser-based absorption technique), and the efficiency of each technique is presented and discussed. Both methods presented relatively low-cost implementation, and calibration procedure assured the quality of the results. The results from the experimental set-up were in agreement in shape and amplitude.

show abstract

“…In addition to the flow resistance, the Fr is often used as a criterion for determining the existence of roll waves. (Arai et al, 2013;Ferreira et al, 2015;Smith et al, 2011;Thual, 2013). Julien and Hartley (1986) emphasized that the critical Fr for the occurrence of roll waves in the laminar region was 0.74.…”

mentioning

confidence: 99%

An experimental study on the evolution law of roll wave parameters in overland flow

Fang¹,

Pan²,

Zhang

et al. 2021

Hydrological Processes

View full text Add to dashboard Cite

Roll waves commonly occur in overland flow and have an important influence on the progress of soil erosion on slopes. This study aimed to explore the evolution and mechanism of roll waves on steep slopes. The potential effects of flow rate, rainfall intensity and bed roughness on the laws controlling roll wave parameters were investigated. The flow rates, rainfall intensities and bed roughness varied from 5 to 30 L/min, 0 to 150 mm/h, and 0.061 to 1.700 mm, respectively. The results indicate that roll waves polymerize significantly along the propagation path, and bed roughness and rainfall affect the generation and evolution of roll waves. The wave velocity, length and height decreased with bed roughness, whereas the wave frequency increased with increasing bed roughness under fixed flow rate and rainfall intensity conditions. Rainfall increased the wave velocity and wavelength and decreased the wave frequency. The wave velocity, height and wavelength tended to increase with an increasing flow rate. Rainfall promoted the generation of roll waves, whereas bed roughness had the opposite effect. The generation of roll waves is closely related to the Froude number (Fr) and flow resistance. In this experiment, the range of the Reynolds number for the roll waves generated in the laminar region was 142–416, and the range of the flow resistance coefficient was 0.64–4.85. The critical value of the Fr for flow instability in the laminar region was approximately 0.57. Exploring the generation and evolution law of roll waves is necessary for understanding the processes and dynamic mechanisms of slope soil erosion.

show abstract

Natural Hazards Modeling: From Runoff to Hyperconcentrated Flows – Roll Waves Generation

Cited by 4 publications

References 8 publications

Response of roll wave to suspended load and hydraulics of overland flow on steep slope

Response of roll wave to suspended load and hydraulics of overland flow on steep slope

Non-intrusive techniques to measure roll waves level evolving in a flume

An experimental study on the evolution law of roll wave parameters in overland flow

Contact Info

Product

Resources

About