scholarly journals A prototype experiment of debris flow control with energy dissipation structures

2011 ◽  
Vol 60 (3) ◽  
pp. 971-989 ◽  
Author(s):  
Zhao Yin Wang ◽  
Lijian Qi ◽  
Xuzhao Wang
Keyword(s):  
Energy Dissipation ◽  
Debris Flow ◽  
Flow Control

scholarly journals Global energy fluxes in turbulent channels with flow control

2018 ◽  
Vol 857 ◽  
pp. 345-373 ◽  
Author(s):  
Davide Gatti ◽  
Andrea Cimarelli ◽  
Yosuke Hasegawa ◽  
Bettina Frohnapfel ◽  
Maurizio Quadrio
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Energy Dissipation ◽  
Velocity Field ◽  
Flow Control ◽  
Reynolds Shear Stress ◽  
Power Input ◽  
Energy Fluxes ◽  
Mean Velocity ◽  
The Mean

This paper addresses the integral energy fluxes in natural and controlled turbulent channel flows, where active skin-friction drag reduction techniques allow a more efficient use of the available power. We study whether the increased efficiency shows any general trend in how energy is dissipated by the mean velocity field (mean dissipation) and by the fluctuating velocity field (turbulent dissipation). Direct numerical simulations (DNS) of different control strategies are performed at constant power input (CPI), so that at statistical equilibrium, each flow (either uncontrolled or controlled by different means) has the same power input, hence the same global energy flux and, by definition, the same total energy dissipation rate. The simulations reveal that changes in mean and turbulent energy dissipation rates can be of either sign in a successfully controlled flow. A quantitative description of these changes is made possible by a new decomposition of the total dissipation, stemming from an extended Reynolds decomposition, where the mean velocity is split into a laminar component and a deviation from it. Thanks to the analytical expressions of the laminar quantities, exact relationships are derived that link the achieved flow rate increase and all energy fluxes in the flow system with two wall-normal integrals of the Reynolds shear stress and the Reynolds number. The dependence of the energy fluxes on the Reynolds number is elucidated with a simple model in which the control-dependent changes of the Reynolds shear stress are accounted for via a modification of the mean velocity profile. The physical meaning of the energy fluxes stemming from the new decomposition unveils their inter-relations and connection to flow control, so that a clear target for flow control can be identified.

Efficiency of Slot-Check Dam Group on Debris Flow Control in Shengou Basin, Kunming, China

2014 ◽  
pp. 37-43 ◽  
Author(s):  
Yuhua Zou ◽  
Kaiheng Hu ◽  
Xiaoqing Chen ◽  
Wei Zhong
Keyword(s):  
Debris Flow ◽  
Flow Control ◽  
Check Dam

Flume investigation of cylindrical baffles for dissipation of debris flow energy

2021 ◽  
Author(s):  
Chan-Young Yune ◽  
Beom-Jun Kim
Keyword(s):  
Energy Dissipation ◽  
Debris Flow ◽  
Debris Flows ◽  
High Speed ◽  
Flow Characteristics ◽  
Digital Camera ◽  
Major Effect ◽  
Small Scale ◽  
Design Guideline ◽  
Flow Energy

<p>A debris flow with a high speed along valleys has been reported to cause serious damages to urban area or infrastructure. To prevent debris flow disaster, countermeasures for flow-impeding structures are installed on the flow path of debris flows. Recently, an installation of cylindrical baffles which are open-type countermeasures has increased because of a low construction cost, filtering out rocks, and an increased hydraulic continuity. However, a comprehensive design guideline for specification and arrangement on cylindrical baffles has not yet been suggested. Moreover, the design of baffle installation is mainly based on empirical approaches as the influence of baffle array on debris mobility is not well understood. In this study, to investigate the effect of cylindrical baffles on the flow characteristics of debris flow, a series of small-scale flume tests were performed according to the varying baffle height and row numbers of installed baffles. High-speed cameras and digital camera to record the flow interaction with baffles were installed at the top and side of the channel. To reproduce the viscosity of debris flows caused by fine-grained soil in the flume, glycerin was mixed with debris materials (sand and gravel). After the test, the velocity and energy dissipation according to various baffle arrays were estimated. Test results showed that the installation of baffles reduced the frontal velocity of debris flows. Furthermore, taller baffles also increased the effect of the energy dissipation in debris flows, but additional rows of the baffle did not have a major effect on the energy dissipation. Thus, increasing the height of baffle led to an increased efficiency of energy dissipation of debris flows.</p>

Experimental study on the characteristics of a debris-flow drainage channel with an energy dissipation structure

2016 ◽  
Vol 76 (1) ◽  
pp. 341-351 ◽  
Author(s):  
Jiangang Chen ◽  
Xiaoqing Chen ◽  
Wanyu Zhao ◽  
Xianbin Yu ◽  
Xiaojun Wang
Keyword(s):  
Experimental Study ◽  
Energy Dissipation ◽  
Debris Flow ◽  
Drainage Channel ◽  
Dissipation Structure

An effectiveness evaluation method for debris flow control engineering for cascading hydropower stations along the Jinsha River, China

2020 ◽  
Vol 266 ◽  
pp. 105472
Author(s):  
Guisheng Hu ◽  
Shufeng Tian ◽  
Ningsheng Chen ◽  
Mei Liu ◽  
Marcelo Somos-Valenzuela
Keyword(s):  
Debris Flow ◽  
Flow Control ◽  
Evaluation Method ◽  
Effectiveness Evaluation ◽  
Jinsha River ◽  
Control Engineering ◽  
Hydropower Stations

An Approach to the Forecasting of Debris Flow Hazard by Storms from Large Waste-Dump at Open Pit Mines

2014 ◽  
Vol 1065-1069 ◽  
pp. 2337-2341
Author(s):  
Xiao Fei Jing ◽  
Ke Hui Liu ◽  
Zhi Yong Cai ◽  
Xiao Zhou
Keyword(s):  
Debris Flow ◽  
Flow Control ◽  
Open Pit ◽  
Waste Dump ◽  
Research Project ◽  
Open Pit Mines ◽  
Flow Motion ◽  
The Impact ◽  
Debris Flow Hazard ◽  
Debris Flow Disaster

In order to explore the impact of debris flow in large waste-dump which under the situation of rainstorm could cause disasters to the downstream region of the life and property; the research project has chosen a large waste-dump as the engineering background in Jiuzhaigou, Sichuan. According to the theory of the debris flow motion, we have made a deep analysis about the possibilities that waste-dump could cause debris flow disaster under the different frequency of rainstorm; and carried on the forecast analysis about the scope and degree of the calamity in the downstream which caused by the debris flow. The results can provide a reference for debris flow control in the lower reaches.

scholarly journals Engineering Planning Method and Control Modes for Debris Flow Disasters in Scenic Areas

2021 ◽  
Vol 9 ◽  
Author(s):  
Xing-Long Gong ◽  
Xiao-Qing Chen ◽  
Kun-Ting Chen ◽  
Wan-Yu Zhao ◽  
Jian-Gang Chen
Keyword(s):  
Debris Flow ◽  
Flow Control ◽  
Debris Flows ◽  
Extreme Rainfall ◽  
Planning Method ◽  
Extreme Rainfall Events ◽  
Field Investigations ◽  
Systematic Planning ◽  
And Control ◽  
Jiuzhaigou Valley

Compared with debris flows in other areas, debris flows in scenic areas not only seriously threaten residents, tourists, roads, walkways, and other infrastructure, but also cause considerable damage to the landscapes and ecosystems of these areas. Extreme rainfall events in the future will increase the complexities and challenges involved in debris flow control in scenic areas. Currently, the systematic planning of the entire scenic area is not considered in the treatment of debris flows. It is not possible to realize the rapid planning of any debris flow gully control project in a scenic area and to quantify the volume of debris flow material retained by each engineering structure. Based on field investigations and data collected from debris flow control projects in gullies in Jiuzhaigou Valley, China, an engineering planning method for debris flow control projects in scenic areas is herein proposed, and the challenges confronting existing control projects in scenic areas are discussed. Moreover, based on the example of Jiuzhaigou Valley, corresponding control engineering schemes for debris flow gullies in Xiajijie Lake Gully, Zhuozhui Gully, Xuan Gully, Pingshitou Gully, and West-Zhuozhui Gully are formulated. Four control modes for debris flow disasters in scenic areas are proposed, namely, “blocking + deposit stopping,” “deposit stopping,” “blocking,” and “drainage + deposit stopping,” which provide a systematic control strategy for post-earthquake debris flow disaster management in Jiuzhaigou Valley and other similar scenic areas.

scholarly journals Development of the debris flow control elastic barrage design methodology

2020 ◽  
Vol 10 (2/2020) ◽  
pp. 127-137
Author(s):  
Givi Gavardashvili ◽  
◽  
Edward Kukhalashvili ◽  
Inga Iremashvili ◽  
Shorena Kupreishvili ◽  
...  
Keyword(s):  
Debris Flow ◽  
Flow Control ◽  
Design Methodology
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