scholarly journals Research on the Normal Use of a Plug Discharge Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Wen Liu ◽  
Jun Deng ◽  
Zhong Tian ◽  
Faxing Zhang
Keyword(s):  
Physical Model ◽  
Structural Damage ◽  
Surface Profile ◽  
Similarity Criterion ◽  
Model Tests ◽  
Cavitation Number ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Discharge Tunnel ◽  
Physical Model Tests

This study analyzed the normal use of an unusual flood-releasing tunnel with a plug dissipator. Firstly, normal physical model tests based on the Froude criterion (1 : 50) were finished. Secondly, depression physical model tests based on the Froude criterion (1 : 50) and cavitation similarity criterion were finished. Thirdly, 3-dimensional numerical simulation of flow field was finished, and free surface profile was captured, which was based on RNG k-ε two-equation turbulence model and VOF method. The focus of this study is on the relationship between normal use and cavitation characteristics (e.g., pressure, turbulence kinetic energy, and cavitation number). The results show that lowering the reservoir water level, reduced by 20.41 m at most, increases the risk of cavitation of a plug discharge tunnel, which means with the decrease of the flow cavitation number, the possibility of structural damage will increase dramatically, while reducing the outlet height can effectively raise the flow cavitation number, ensuring the safety of normal use. Under the conditions of free outflow, for the H1/e values of 4.45, 4.00, and 3.55, the conditions in which the tunnel meets the requirements of anticavitation are h/D ≤ 0.42, h/D ≤ 0.39, and h/D ≤ 0.35, respectively. In addition, the discharge capacity of the tunnel is not significantly reduced with the lowering of outlet height, implying that operation under a low water head of the plug discharge tunnel, as low as 3.55 of H1/e in the test, is feasible. The results obtained in this study can serve as reference information in engineering design of the plug discharge tunnel.

scholarly journals Deformation Mechanism of Deposit Landslide Induced by Fluctuations of Reservoir Water Level Based on Physical Model Tests

2021 ◽  
Author(s):  
Zihua Jiang ◽  
Huanling Wang ◽  
Weichau Xie
Keyword(s):  
Water Level ◽  
Physical Model ◽  
Failure Process ◽  
Model Tests ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Deformation And Failure ◽  
Landslide Stability ◽  
Level Difference ◽  
Physical Model Tests

Abstract Located in reservoir area of Dahuaqiao Hydropower Station in Lancang River, the Dahua ancient deposit landslide exhibits high possibility of reactivation due to reservoir impoundment. In this study, physical model tests are conducted to investigate the variations of groundwater, deformation, and failure process of the landslide under different fluctuation speeds of reservoir water level. Influence of groundwater on landslide stability when reservoir water level fluctuating is analyzed then. Results indicate that the seepage pressure caused by water level difference can increase landslide displacement. During the dropping process of reservoir water level, the relationship between landslide displacement and water level difference can be described by a power function model. Groundwater has negative effects on stability of landslides, and the damage is characterized by traction landslide. More attentions should be paid on the displacement of the front edge of the landslide during the first rise and drop of reservoir water level. The study provides indispensable information for scheduling reservoir water level in the Dahuaqiao and others similar reservoir areas, thus having vital importance.

The Design of Movable Landslide Physical Model Testing Frame

2011 ◽  
Vol 201-203 ◽  
pp. 1433-1438 ◽  
Author(s):  
Dai Peng Zhao ◽  
Shi Mei Wang ◽  
Yun Zhi Tan ◽  
Xiao Ling Liu
Keyword(s):  
Water Supply ◽  
Water Level ◽  
Physical Model ◽  
Model Testing ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Water Level Variation ◽  
Physical Model Tests ◽  
Uniform Sample ◽  
Mechanism Of Landslide

The small landslide physical model testing frame was designed and made in order to analyze the induction mechanism of landslide by rainfall and reservoir water level variation by adopting the physical model tests. It is consisted by exterior frame, internal body box, water supply and discharge pipelines, hoisting jacks and steel rollers. Some functions such as uniform sample preparation, confined effect reduction, lifting flexibility as well as water level change simulation and so on are realized through some design technologies like removable model frame, adjustable width, rotatable frame body ,mobile model frame and water supply and discharge pipeline and so on.

scholarly journals PORT RESONANCE MITIGATION MODELED INTRODUCING ARJ-R STRUCTURES

2020 ◽  
pp. 38
Author(s):  
Jose A. GONZALEZ-ESCRIVA ◽  
Josep R. MEDINA ◽  
Joaquin M. GARRIDO
Keyword(s):  
Reflection Coefficient ◽  
Physical Model ◽  
Large Scale ◽  
Low Frequency ◽  
Model Tests ◽  
Wave Interference ◽  
Low Frequency Oscillations ◽  
Physical Model Tests ◽  
Similar Cost ◽  
Interference Mechanism

ARJ-R caissons are based on the "long-circuit" concept (Medina et al, 2016) that allows the extension of the destructive wave interference mechanism to mitigate low frequency oscillations without enlarging the width of the caisson. The performance of the ARJ-R caissons is referred to its reflection coefficient (Cr) which was obtained through large-scale physical model tests (Gonzalez-Escriva et al, 2018). In this paper, the effectiveness of Anti-Reflective Jarlan-type structures for Port Resonance mitigation (ARJ-R) has been assessed numerically for the port of Denia (Spain). ARJ-R structures are constructible, with similar dimensions as conventional vertical quay caissons and with a similar cost (15percent more than conventional vertical caisson).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/LomQEVpvjik

scholarly journals OPTIMIZATION OF THE WAVECAT WAVE ENERGY CONVERTER

2012 ◽  
Vol 1 (33) ◽  
pp. 5 ◽  
Author(s):  
Hernan Fernandez ◽  
Gregorio Iglesias ◽  
Rodrigo Carballo ◽  
Alberte Castro ◽  
Marcos Sánchez ◽  
...  
Keyword(s):  
Physical Model ◽  
Wave Energy ◽  
Model Tests ◽  
Irregular Waves ◽  
Intermediate Water ◽  
Plan View ◽  
Santiago De Compostela ◽  
Wave Energy Converters ◽  
Physical Model Tests ◽  
The Difference

The development of efficient, reliable Wave Energy Converters (WECs) is a prerequisite for wave energy to become a commercially viable energy source. Intensive research is currently under way on a number of WECs, among which WaveCat©—a new WEC recently patented by the University of Santiago de Compostela. In this sense, this paper describes the WaveCat concept and its ongoing development and optimization. WaveCat is a floating WEC intended for operation in intermediate water depths (50–100 m). Like a catamaran, it consists of two hulls—from which it derives its name. The difference with a conventional catamaran is that the hulls are not parallel but convergent; they are joined at the stern, forming a wedge in plan view. Physical model tests of a 1:30 model were conducted in a wave tank using both regular and irregular waves. In addition to the waves and overtopping rates, the model displacements were monitored using a non-intrusive system. The results of the physical model tests will be used to validate the 3D numerical model, which in turn will be used to optimize the design of WaveCat for best performance under a given set of wave conditions.

scholarly journals LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

2020 ◽  
pp. 15
Author(s):  
Wouter Ockeloen ◽  
Coen Kuiper ◽  
Sjoerd van den Steen
Keyword(s):  
Water Management ◽  
Physical Model ◽  
Large Scale ◽  
Wadden Sea ◽  
Model Tests ◽  
Small Scale ◽  
Water Safety ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

scholarly journals Study on the Water-Physical Properties of the Cement-Plaster Bonded Rock-Like Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yong Zhang ◽  
Zhiguo Cao ◽  
Xiaomeng Shi
Keyword(s):  
Physical Properties ◽  
Physical Model ◽  
Coupling Model ◽  
Model Tests ◽  
Physical Parameters ◽  
Test Results ◽  
Physical Model Tests ◽  
Fluid Coupling ◽  
Softening Coefficient ◽  
Solid Fluid Coupling

The cement-plaster bonded rock-like material is one of the most commonly used materials to simulate different rocks in physical model tests. However, the applicability of this material in solid-fluid coupling model tests is not clear because there are few research studies on the water-physical properties of this material and its similarity to the actual rock is uncertain. This paper presents a systemic experimental study on the water-physical properties of the cement-plaster bonded rock-like materials. The parameters of rock-like materials, including water absorption, softening coefficient, and permeability coefficient, were compared with those of actual rocks to analyse the applicability of such material. Then, the influence of proportion on the water-physical properties of this material was discussed. By multiple regression analysis of the test results, empirical equations between the water-physical parameters and proportions were proposed. The equations can be used to estimate the water-physical properties of cement-plaster bonded rock-like materials with specific proportion and thus to select suitable materials in the solid-fluid coupling physical model tests.

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