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Fang Liu
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, 135 Yaguan Road, Haihe Education Park, Tianjin 30035, PR China

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Journal article
Published: 05 November 2020 in Energy Conversion and Management
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The advantageous performance on energy conversion of triangular prisms in Flow Induced Motion Energy Conversion (FIMEC) system has been verified by previous researches. In this paper, the magnetic flux density (B) was introduced into the mathematical model to analyze damping (ctotal), active power (Pharn) and energy conversion efficiency (ηharn) in FIMEC system. A physical model was established to adjusted the magnetic flux density (B) by varying the excitation voltages (VB) of Power Take-Off System (PTO). Free decay tests proved that physical model matched well with the mathematical model. Based on the physical model, the Flow Induced Motion (FIM) characteristic and energy conversion were analyzed and discussed, furthermore a control strategy to harness energy in galloping branch for Hard Galloping (HG) was proposed and verified. As B is high HG occurs, otherwise soft galloping (SG) occurs. By using the control strategy, the galloping can be self-excited by adjusting B, which is beneficial to the energy conversion of FIM. In the tests, the peaks of active power and efficiency are Pharn ≈ 2W and ηharn ≈ 3.1% in Vortex Induced Vibration (VIV) upper branch, Pharn ≈ 21.5 W and ηharn ≈ 3.5% in galloping branch.

ACS Style

Xiang Yan; Jijian Lian; Fang Liu; Xiaoqun Wang; Nan Shao. Hydrokinetic energy conversion of Flow-induced motion for triangular prism by varying magnetic flux density of generator. Energy Conversion and Management 2020, 227, 113553 .

AMA Style

Xiang Yan, Jijian Lian, Fang Liu, Xiaoqun Wang, Nan Shao. Hydrokinetic energy conversion of Flow-induced motion for triangular prism by varying magnetic flux density of generator. Energy Conversion and Management. 2020; 227 ():113553.

Chicago/Turabian Style

Xiang Yan; Jijian Lian; Fang Liu; Xiaoqun Wang; Nan Shao. 2020. "Hydrokinetic energy conversion of Flow-induced motion for triangular prism by varying magnetic flux density of generator." Energy Conversion and Management 227, no. : 113553.

Journal article
Published: 03 September 2020 in Applied Sciences
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A 1:25 scale physical model test was employed to study the plane gate vibration and holding force under the conditions of the fixed gate opening and closing process, respectively. We paid more attention to the characteristics of the gate vibration, holding force and the failure of gate-closing in closing process. The correlation between gate vibration and holding force was further examined. The results show that vertical vibration is weaker than the lateral and horizontal vibrations in fixed gate opening and is stronger than the lateral and vertical vibrations in closing process. Gate vertical vibration is self-excited vibration with a frequency of 7–14 Hz. Besides, crawl vibration in closing process is related to the upstream water depth. The higher the water level is, the earlier the crawl vibration appears. After the crawl stage, plane gate stops motion at a certain distance from the chamber floor and then the failure of gate-closing happens. Finally, gate vibration in three directions is significantly correlated with the holding force. In closing process, holding force has positive correlation with the vertical vibration and has negative correlation with the lateral and horizontal vibrations. In the crawl stage, the average of correlation coefficient in lateral, vertical and horizontal direction is −0.723, 0.733 and −0.664, respectively. Thus, the influence of gate vibration on holding force should be taken into consideration in determining the hoists capacity.

ACS Style

Yanzhao Wang; Guobin Xu; Wensheng Li; Fang Liu; Yu Duan. Characteristics of Plane Gate Vibration and Holding Force in Closing Process by Experiments. Applied Sciences 2020, 10, 6111 .

AMA Style

Yanzhao Wang, Guobin Xu, Wensheng Li, Fang Liu, Yu Duan. Characteristics of Plane Gate Vibration and Holding Force in Closing Process by Experiments. Applied Sciences. 2020; 10 (17):6111.

Chicago/Turabian Style

Yanzhao Wang; Guobin Xu; Wensheng Li; Fang Liu; Yu Duan. 2020. "Characteristics of Plane Gate Vibration and Holding Force in Closing Process by Experiments." Applied Sciences 10, no. 17: 6111.

Journal article
Published: 21 February 2020 in Applied Sciences
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Low-temperature discharged water from thermally-stratified reservoirs in spring and summer will have a negative environmental impact on fish breeding and agricultural irrigation downstream. The temperature-control curtain (TCC) is a selective withdrawal structure that can effectively change the discharged water temperature. Compared with a traditional selective withdrawal project, a TCC project has the advantages of low cost and simple construction and can even be added to operating reservoirs without impacting power generation. Analysis of the load characteristics is the key to the application of TCC engineering. This paper establishes a three-dimensional numerical model simulation and verifies it with physical model experimental results. The crucial parameters affecting the load characteristics of TCC are investigated, including the water blocking rate, area ratio, inclination ratio, inflow velocity, and water temperature stratification ratio. The results show that: (1) This numerical simulation approach can be used to predict the drag coefficient and the load of a TCC; (2) the water blocking rate has the greatest influence on the drag coefficient, and it is the most critical indicator of the TCC load; and (3) the drag coefficient exponentially increases with an increasing water blocking rate, quadratically increases with an increasing area ratio, linearly increases with an increasing inclination ratio, and linearly increases with an increasing water temperature stratification ratio.

ACS Style

Jijian Lian; Chunxi Liu; Haijun Wang; Fang Liu; Wenhe Lu; Yue Zhao. Simulation and Experimental Analysis on the Load Characteristics of a Temperature-Control Curtain in a Thermally-Stratified Reservoir. Applied Sciences 2020, 10, 1461 .

AMA Style

Jijian Lian, Chunxi Liu, Haijun Wang, Fang Liu, Wenhe Lu, Yue Zhao. Simulation and Experimental Analysis on the Load Characteristics of a Temperature-Control Curtain in a Thermally-Stratified Reservoir. Applied Sciences. 2020; 10 (4):1461.

Chicago/Turabian Style

Jijian Lian; Chunxi Liu; Haijun Wang; Fang Liu; Wenhe Lu; Yue Zhao. 2020. "Simulation and Experimental Analysis on the Load Characteristics of a Temperature-Control Curtain in a Thermally-Stratified Reservoir." Applied Sciences 10, no. 4: 1461.

Journal article
Published: 16 February 2020 in Applied Sciences
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Finding an appropriate shape for the releasing building is thoroughly relevant given the energy dissipation and safety requirements of a high dam in a sediment-laden river. Thirty-six physical experiments on trajectory energy dissipation were conducted, researching the influence of three overflow shapes (contraction ratios of 0.5, 0.4, and 0.3) with four sediment concentrations (0, 50, 150, and 250 kg/m3) on the discharge, flow regime, and hydrodynamic pressure of a plunge pool slab. The experimental results demonstrated that the flow coefficient gradually decreased as the contraction ratio decreased in a relatively high weir head, regardless of the sediment concentration. The water nappe narrowed and the length of the longitudinal trajectory increased as the outlet shrinkage and sediment concentration decreased. With the increase in sediment concentration, the nappe regime approached stability, and the flow in the plunge pool tended toward small rolling, causing the impact pressure and fluctuating pressure to increase. Changes in overflow shape had little effect on the position of pressure peak, but the value became lower as the ratio diminished. The influence on the hydrodynamic pressure by outlet shrinkage became attenuated while the sediment concentration increased. The fluctuating energy and vortex scale were enhanced due to the increased viscosity with increasing sediment concentrations.

ACS Style

Jijian Lian; Hongxia Yin; Fang Liu; Huiping Li; Wenjuan Gou. Effects of Outlet Shrinkage on Hydraulics in Hyper-Concentrated Sediment-Laden Flow. Applied Sciences 2020, 10, 1332 .

AMA Style

Jijian Lian, Hongxia Yin, Fang Liu, Huiping Li, Wenjuan Gou. Effects of Outlet Shrinkage on Hydraulics in Hyper-Concentrated Sediment-Laden Flow. Applied Sciences. 2020; 10 (4):1332.

Chicago/Turabian Style

Jijian Lian; Hongxia Yin; Fang Liu; Huiping Li; Wenjuan Gou. 2020. "Effects of Outlet Shrinkage on Hydraulics in Hyper-Concentrated Sediment-Laden Flow." Applied Sciences 10, no. 4: 1332.

Journal article
Published: 07 February 2020 in Applied Sciences
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The advantageous performance in terms of energy conversion for the flow-induced motion (FIM) of T-section prisms has been experimentally reported recently. In order to further understand the oscillation and energy conversion of multiple T-section prisms, a series of tests of two T-section prisms arranged in tandem with five different spacing ratios (3 ≤ L/D ≤ 15) and seven load resistances (8 Ω ≤ RL ≤ 41 Ω) were conducted. The effects of the spacing ratio and load resistances on energy conversion were discussed. The main conclusions can be summarized as follows. For most tests, the amplitudes of the upstream T-section prism (UTP) and downstream T-section prism (DTP) were both lower than the amplitude of the single T-section prism (STP) due to the mutual interference of the two prisms. Because of the mutual interference, the active powers of UTP and DTP were both less than that of STP, but at some special spacing ratios or load resistances, the mutual interference benefited the energy converted by the two prisms. In the presented tests, the total optimal active power of the upstream T-section prism and downstream T-section prism (UTP + DTP) was 30.12 W, which was 1.5 times that of STP (20.12 W).

ACS Style

Nan Shao; Guobin Xu; Fang Liu; Xiang Yan; Xiaoqun Wang; Heng Deng; Zheng Zheng. Experimental Study on the Flow-Induced Motion and Hydrokinetic Energy of Two T-section Prisms in Tandem Arrangement. Applied Sciences 2020, 10, 1136 .

AMA Style

Nan Shao, Guobin Xu, Fang Liu, Xiang Yan, Xiaoqun Wang, Heng Deng, Zheng Zheng. Experimental Study on the Flow-Induced Motion and Hydrokinetic Energy of Two T-section Prisms in Tandem Arrangement. Applied Sciences. 2020; 10 (3):1136.

Chicago/Turabian Style

Nan Shao; Guobin Xu; Fang Liu; Xiang Yan; Xiaoqun Wang; Heng Deng; Zheng Zheng. 2020. "Experimental Study on the Flow-Induced Motion and Hydrokinetic Energy of Two T-section Prisms in Tandem Arrangement." Applied Sciences 10, no. 3: 1136.

Journal article
Published: 01 February 2020 in Water
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A better understanding of the atomized rain characteristics in low ambient pressure areas is beneficial in reducing the jeopardizing effect of flood discharge atomization on high-altitude hydropower stations. A random splash experiment is designed with two measurement planes to investigate the effects of low ambient pressure on downstream atomized rain under the complicated conditions of low ambient pressure (within 0.60P0~1.00P0) and high waterjet velocity (at a magnitude of 10 m/s). The results demonstrate that the atomized rain (rain intensity ≥ 2 mm/h) downstream, characterized by two-dimensional distribution, can be enhanced by decreasing the ambient pressure and by increasing the inflow discharge. When the ambient pressure decreases at the same inflow discharge, both the distance of the rain intensity lines (40 mm/h, 10 mm/h, 2 mm/h) in the horizontal plane from the constricted nozzle outlet and the average rain amount in the inclined plane within the atomized source ratio of ((0~30) × 10−3)% appear as “linear” growth. With the ambient pressure decreasing by 0.10P0, the range of those characteristic rain intensity lines is expanded by 0.68%~1.37%, and the average rain amount is enlarged by 11.06%~20.48%. When keeping the low ambient pressure unchanged, both the point average rain intensity reduction along the releasing centerline and the surface average rain amount growth with increased inflow discharge all follow an exponential function. The aeration reduction in the waterjet boundary and the resistance reduction in atomized water-droplets are contributing factors for the enhancement effect of low ambient pressure. This study can enable the establishment of a foundation to further predict flood discharge atomization in a high-altitude environment.

ACS Style

Dan Liu; Jijian Lian; Fang Liu; Dongming Liu; Bin Ma; Jizhong Shi; Liu. An Experimental Study on the Effects of Atomized Rain of a High Velocity Waterjet to Downstream Area in Low Ambient Pressure Environment. Water 2020, 12, 397 .

AMA Style

Dan Liu, Jijian Lian, Fang Liu, Dongming Liu, Bin Ma, Jizhong Shi, Liu. An Experimental Study on the Effects of Atomized Rain of a High Velocity Waterjet to Downstream Area in Low Ambient Pressure Environment. Water. 2020; 12 (2):397.

Chicago/Turabian Style

Dan Liu; Jijian Lian; Fang Liu; Dongming Liu; Bin Ma; Jizhong Shi; Liu. 2020. "An Experimental Study on the Effects of Atomized Rain of a High Velocity Waterjet to Downstream Area in Low Ambient Pressure Environment." Water 12, no. 2: 397.

Journal article
Published: 16 January 2020 in Engineering Failure Analysis
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The incomplete closure of a leaf gate frequently occurs in recent years, while the failure analysis and feasible solutions have not been reported in many previous works. In this paper, failure analysis of a leaf gate jammed under submerged discharge is carried out using an equilibrium equation to study the horizontal and vertical forces in the closing process. The results of model test and numerical simulation show that the excessive friction coefficient is the main reason for leaf gate jammed. On the premise of the leaf gate configuration certainty, the limiting friction coefficient is just related to water head difference. Changing the key beam position and decreasing the gate lip angle have no effect on closing. Adding the area of the water column such as widening the gate and adding a convex bottom edge are feasible solutions to solve the problem of gate jammed. The results also yield a simplified forecasting formula of water head loss, which provides a reference for the solution of similar problems and the design of a new leaf gate.

ACS Style

Chao Ma; Chuanming Sheng; Jijian Lian; Bin Ma; Fang Liu. Failure analysis of a leaf gate jammed in closing process. Engineering Failure Analysis 2020, 110, 104391 .

AMA Style

Chao Ma, Chuanming Sheng, Jijian Lian, Bin Ma, Fang Liu. Failure analysis of a leaf gate jammed in closing process. Engineering Failure Analysis. 2020; 110 ():104391.

Chicago/Turabian Style

Chao Ma; Chuanming Sheng; Jijian Lian; Bin Ma; Fang Liu. 2020. "Failure analysis of a leaf gate jammed in closing process." Engineering Failure Analysis 110, no. : 104391.

Journal article
Published: 06 January 2020 in International Journal of Environmental Research and Public Health
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Ground and environmental vibrations induced by high dam flood discharge from the Xiangjiaba hydropower station (XHS) has significant adverse effects on nearby building safety and the physical and mental health of surrounding residents. As an effective approach to simulate the flow-induced vibration of hydraulic structures, the hydro-elastic experiment approach has been extensively applied and researched by Chinese scholars, but the relevant systematic research is rarely reported in international journals. Firstly, the hydraulic and structural dynamic similarity conditions that should be satisfied by the hydro-elastic model are briefly reviewed and derived. A hydro-elastic model of the XHS was further constructed using self-developed high-density rubber, and the vibration isolation system (including open trenches and flexible connects) was applied to avoid the external disturbances of pump operation, vehicle vibration and other experiments in the laboratory. Based on the data of model and prototype dynamic tests, a back propagation (BP) neural network was established to map the acceleration of the physical model to the ground in the prototype. In order to reduce the ground vibration, experiments were carried out to meticulously evaluate the ground vibration intensity under more than 600 working conditions, and the optimal operation scheme under different discharge volumes is presented here in detail. According to the prototype test data in 2013, 2014, and 2015, ground vibrations were significantly reduced by applying the presented optimal operation principle which indicates that the presented hydro-elastic approach and the vibration attenuation operation scheme were effective and feasible.

ACS Style

Jijian Lian; Lin Chen; Chao Liang; Fang Liu. Presentation and Verification of an Optimal Operating Scheme Aiming at Reducing the Ground Vibration Induced by High Dam Flood Discharge. International Journal of Environmental Research and Public Health 2020, 17, 377 .

AMA Style

Jijian Lian, Lin Chen, Chao Liang, Fang Liu. Presentation and Verification of an Optimal Operating Scheme Aiming at Reducing the Ground Vibration Induced by High Dam Flood Discharge. International Journal of Environmental Research and Public Health. 2020; 17 (1):377.

Chicago/Turabian Style

Jijian Lian; Lin Chen; Chao Liang; Fang Liu. 2020. "Presentation and Verification of an Optimal Operating Scheme Aiming at Reducing the Ground Vibration Induced by High Dam Flood Discharge." International Journal of Environmental Research and Public Health 17, no. 1: 377.

Journal article
Published: 27 December 2019 in Energy
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Previous studies proved that the triangular prism would go into galloping branch with high amplitude and low frequency. In order to evaluate the energy conversion capacity, a series experiments of flow induced motion (FIM) for triangular prism with physical springs are conducted in the Reynolds number range of 29,559 ≤ Re ≤ 119,376 by varying load resistance, stiffness, mass ratio and aspect ratio. Selective aspect ratios are applied to enhance the hydrokinetic energy captured by the generator. A physical model is used to control the change of load resistance and spring stiffness for a fast and precise oscillator modeling. The analysis of oscillation responses and energy conversion are carried out based on the statistical evaluation of displacement time-history and voltage signals. The effects of system stiffness, mass ratio, aspect ratio and load resistance on the active power (Pharn) of the triangular prism are presented and discussed. The main conclusions can be summarized as follows: (1) The best branch of the triangular prism energy conversion is galloping branch. (2) In the tests, the maximum active power Pharn = 23.37 W and the corresponding efficiency ηharn = 5.21%. The maximum energy conversion efficiency ηharn = 6.17% with the corresponding active power Pharn = 2.94 W. (3) With the increase of the stiffness (K) and the reduce of the mass ratio (m*), the Pharn rises up. (4) The higher aspect ratio (α) can be easier self-excited to galloping from the vortex induced vibration (VIV) but has a negative influence on the Pharn of the galloping branch.

ACS Style

Nan Shao; Jijian Lian; Fang Liu; Xiang Yan; Peiyao Li. Experimental investigation of flow induced motion and energy conversion for triangular prism. Energy 2019, 194, 116865 .

AMA Style

Nan Shao, Jijian Lian, Fang Liu, Xiang Yan, Peiyao Li. Experimental investigation of flow induced motion and energy conversion for triangular prism. Energy. 2019; 194 ():116865.

Chicago/Turabian Style

Nan Shao; Jijian Lian; Fang Liu; Xiang Yan; Peiyao Li. 2019. "Experimental investigation of flow induced motion and energy conversion for triangular prism." Energy 194, no. : 116865.

Journal article
Published: 11 July 2019 in Applied Sciences
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It is of great significance to study the ventilation characteristics of air supply systems in spillway tunnels, especially for high dams. In this paper, a brief theoretical approach to evaluate the ventilation characteristics of a multi-intake-well air supply system was established, which was mainly derived from the Bernoulli equation and continuity equation. With this approach, an analysis of the ventilation characteristics of the Jinping-I project spillway tunnel was carried out. A comparison of the theoretical results and prototype data suggested the theoretical approach to be valid and practical. The value of the drag coefficient at the air-water interface should be calibrated before evaluation because the drag coefficient is crucial for the accuracy of theoretical results. In addition, the influences of certain structural factors of the spillway tunnel and air intake well on the ventilation characteristics of multi-intake-well air supply systems are investigated.

ACS Style

Jijian Lian; Panhong Ren; Chunfeng Qi; Fang Liu; QunAn Ouyang. A Brief Theoretical Analysis on the Ventilation Characteristics of the Multi-Intake-Well Air Supply System in a Spillway Tunnel. Applied Sciences 2019, 9, 2793 .

AMA Style

Jijian Lian, Panhong Ren, Chunfeng Qi, Fang Liu, QunAn Ouyang. A Brief Theoretical Analysis on the Ventilation Characteristics of the Multi-Intake-Well Air Supply System in a Spillway Tunnel. Applied Sciences. 2019; 9 (14):2793.

Chicago/Turabian Style

Jijian Lian; Panhong Ren; Chunfeng Qi; Fang Liu; QunAn Ouyang. 2019. "A Brief Theoretical Analysis on the Ventilation Characteristics of the Multi-Intake-Well Air Supply System in a Spillway Tunnel." Applied Sciences 9, no. 14: 2793.

Journal article
Published: 24 January 2019 in International Journal of Environmental Research and Public Health
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Flood discharge atomization is a serious challenge that threatens the daily lives of the residents around the dam area as well as the safety of the water conservancy project. This research aims to improve the prediction accuracy of the stochastic splash model. A physical model test with four types of flip bucket is conducted to obtain the hydraulic parameters of the impinging outer edge of the water jet, the relationship of the splashing droplet diameter with its corresponding velocity, and the spatial distribution of the downstream nappe wind. The factors mentioned above are introduced to formulate the empirical model. The rule obtained from the numerical analyses is compared with the results of the physical model test and the prototype observations, which yields a solid agreement. The numerical results indicate that the powerhouse is no longer in the heavy rain area when adopting the flip bucket whose curved surface is attached to the left wall. The rainfall intensity of the powerhouse is significantly weaker than that of other types under the designed condition, so we choose it as the recommended bucket type. Meanwhile, we compare the rainfall intensity distribution of the original bucket and the recommended bucket under different discharge which rates ranging from 150.71 to 1094.9 m3/s. It is found that the powerhouse and the owner camp are no longer in the heavy rain area under all of the working conditions. Finally, it is shown that the atomization influence during the flood discharge can be reduced by using the recommended bucket.

ACS Style

Jijian Lian; Junling He; Fang Liu; Danjie Ran; Xiaoqun Wang; Chang Wang. An Improved Empirical Model for Flood Discharge Atomization and Its Application to Optimize the Flip Bucket of the Nazixia Project. International Journal of Environmental Research and Public Health 2019, 16, 316 .

AMA Style

Jijian Lian, Junling He, Fang Liu, Danjie Ran, Xiaoqun Wang, Chang Wang. An Improved Empirical Model for Flood Discharge Atomization and Its Application to Optimize the Flip Bucket of the Nazixia Project. International Journal of Environmental Research and Public Health. 2019; 16 (3):316.

Chicago/Turabian Style

Jijian Lian; Junling He; Fang Liu; Danjie Ran; Xiaoqun Wang; Chang Wang. 2019. "An Improved Empirical Model for Flood Discharge Atomization and Its Application to Optimize the Flip Bucket of the Nazixia Project." International Journal of Environmental Research and Public Health 16, no. 3: 316.

Journal article
Published: 15 September 2018 in Applied Sciences
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The effect of sediment on the hydraulics of jet energy dissipation is an urgent issue for high dams built on sediment-laden rivers. Accordingly, flume experiments were conducted using a ski-jump type energy dissipator in flows of four sediment concentrations (0 kg/m3, 50 kg/m3, 150 kg/m3, and 250 kg/m3) to determine the effects on discharge, flow regime, and hydrodynamic pressure in a plunge pool. The results demonstrate that the effect of sediment on discharge is constant, regardless of sediment concentration, when compared to fresh water. The width of the nappe decreased with increasing concentrations of sediment. The length of the jet trajectory increased with upstream water head. The time-averaged pressure and fluctuation pressure both exhibited peaks, describing the impact of the jet on the bottom of the plunge pool. The maximum time-averaged pressure and maximum fluctuating pressure both noticeably increased with upstream water head and slightly increased with sediment concentration for a given flow condition. The results also demonstrated that the dominant frequency of fluctuation trends to lower values, and that both the fluctuating energy and vortex scale increase with increasing sediment concentrations due to increased viscosity. These findings can be used to improve energy dissipation in dams on sediment-laden rivers.

ACS Style

Wenjuan Gou; Huiping Li; Yunyi Du; Hongxia Yin; Fang Liu; Jijian Lian. Effect of Sediment Concentration on Hydraulic Characteristics of Energy Dissipation in a Falling Turbulent Jet. Applied Sciences 2018, 8, 1672 .

AMA Style

Wenjuan Gou, Huiping Li, Yunyi Du, Hongxia Yin, Fang Liu, Jijian Lian. Effect of Sediment Concentration on Hydraulic Characteristics of Energy Dissipation in a Falling Turbulent Jet. Applied Sciences. 2018; 8 (9):1672.

Chicago/Turabian Style

Wenjuan Gou; Huiping Li; Yunyi Du; Hongxia Yin; Fang Liu; Jijian Lian. 2018. "Effect of Sediment Concentration on Hydraulic Characteristics of Energy Dissipation in a Falling Turbulent Jet." Applied Sciences 8, no. 9: 1672.

Journal article
Published: 06 August 2018 in Energies
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Flow-induced motion (FIM) performs well in energy conversion but has been barely investigated, particularly for prisms with sharp sections. Previous studies have proven that T-section prisms that undergo galloping branches with high amplitude are beneficial to energy conversions. The FIM experimental setup designed by Tianjin University (TJU) was improved to conduct a series of FIM responses and energy conversion tests on a T-section prism. Experimental results are presented and discussed, to reveal the complete FIM responses and power generation characteristics of the T-section prism under different load resistances and section aspect ratios. The main findings are summarized as follows. (1) Hard galloping (HG), soft galloping (SG), and critical galloping (CG) can be observed by varying load resistances. When the load resistances are low, HG occurs; otherwise, SG occurs. (2) In the galloping branch, the highest amplitude and the most stable oscillation cause high-quality electrical energy production by the generator. Therefore, the galloping branch is the best branch for harvesting energy. (3) In the galloping branch, as the load resistances decrease, the active power continually increases until the prism is suppressed from galloping to a vortex-induced vibration (VIV) lower branch with a maximum active power Pharn of 21.23 W and a maximum ηout of 20.2%. (4) Different section aspect ratios (α) can significantly influence the FIM responses and energy conversions of the T-section prism. For small aspect ratios, galloping is hardly observed in the complete responses, but the power generation efficiency (ηout,0.8 = 27.44%) becomes larger in the galloping branch.

ACS Style

Nan Shao; Jijian Lian; Guobin Xu; Fang Liu; Heng Deng; Quanchao Ren; Xiang Yan. Experimental Investigation of Flow-Induced Motion and Energy Conversion of a T-Section Prism. Energies 2018, 11, 2035 .

AMA Style

Nan Shao, Jijian Lian, Guobin Xu, Fang Liu, Heng Deng, Quanchao Ren, Xiang Yan. Experimental Investigation of Flow-Induced Motion and Energy Conversion of a T-Section Prism. Energies. 2018; 11 (8):2035.

Chicago/Turabian Style

Nan Shao; Jijian Lian; Guobin Xu; Fang Liu; Heng Deng; Quanchao Ren; Xiang Yan. 2018. "Experimental Investigation of Flow-Induced Motion and Energy Conversion of a T-Section Prism." Energies 11, no. 8: 2035.

Journal article
Published: 26 July 2018 in Wear
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In order to study the effects of silica sand on synergistic erosion caused by cavitation, abrasion, and corrosion, vibratory experiments were conducted on ASTM 1045 carbon steel specimens subjected to six particle sizes (0.01–0.1 mm) mixed in nine concentrations (6–300 kg/m3) with tap water or with six concentrations of NaCl (0.5–15%). The experimental results indicate that sand particles larger than 0.04 mm at concentrations of 30–150 kg/m3 increasingly aggravated synergistic erosion with increasing sand particle size and concentration. The difference was observed for sand particles smaller than 0.04 mm: these sands inhibited cavitation erosion at concentrations of 30–300 kg/m3, but aggravated erosion at concentrations of 6–30 kg/m3; the maximum erosion occurred at a concentration of 12 kg/m3. As the concentration of NaCl increased, the erosion due to cavitation and corrosion increased sharply before growing stable above a NaCl concentration of 3.5%. The synergistic erosion caused by cavitation, abrasion, and corrosion was more severe than the erosion in tap water or cavitation-corrosion in a 3.5% NaCl solution, demonstrating that sand has an aggravated effect on synergistic erosion.

ACS Style

Wenjuan Gou; Hui Zhang; Huiping Li; Fang Liu; Jijian Lian. Effects of silica sand on synergistic erosion caused by cavitation, abrasion, and corrosion. Wear 2018, 412-413, 120 -126.

AMA Style

Wenjuan Gou, Hui Zhang, Huiping Li, Fang Liu, Jijian Lian. Effects of silica sand on synergistic erosion caused by cavitation, abrasion, and corrosion. Wear. 2018; 412-413 ():120-126.

Chicago/Turabian Style

Wenjuan Gou; Hui Zhang; Huiping Li; Fang Liu; Jijian Lian. 2018. "Effects of silica sand on synergistic erosion caused by cavitation, abrasion, and corrosion." Wear 412-413, no. : 120-126.

Journal article
Published: 01 December 2017 in Journal of Hydraulic Engineering
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ACS Style

Wei He; Jijian Lian; Chao Ma; MuDan Wu; Fang Liu. Analysis of the Thrust Force on the Temperature-Control Curtain in a Large Stratified Reservoir. Journal of Hydraulic Engineering 2017, 143, 04017049 .

AMA Style

Wei He, Jijian Lian, Chao Ma, MuDan Wu, Fang Liu. Analysis of the Thrust Force on the Temperature-Control Curtain in a Large Stratified Reservoir. Journal of Hydraulic Engineering. 2017; 143 (12):04017049.

Chicago/Turabian Style

Wei He; Jijian Lian; Chao Ma; MuDan Wu; Fang Liu. 2017. "Analysis of the Thrust Force on the Temperature-Control Curtain in a Large Stratified Reservoir." Journal of Hydraulic Engineering 143, no. 12: 04017049.

Journal article
Published: 10 September 2017 in Applied Sciences
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Artificial air entrainment has been widely used to avoid cavitation damage in spillways where high-velocity flow occurs, and its performance is very important for spillway safety. In order to evaluate the performance of the aeration system in the spillway tunnel of the Jinping-I Dam, which is the highest arched dam in the world to date, systematic prototype observation was conducted. Ventilation characteristics of the air supply system and aeration-related characteristics of the aeration devices were examined at the prototype scale. The results showed that air flows smoothly in the air intake well and the real effect of air entrainment of the aeration device was desirable. In contrast with results from laboratory tests with a physical model at a scale of 1/30 following the gravity similarity, it was found that air demand in the prototype is much greater, clearly indicating the scale effect. By summing up and analyzing the air demand ratio of the prototype to the model in some projects, the scale effect was found to be ignorable when the model scale was greater than 1/10. In addition, based on a series of prototype data on air demand, a brief evaluation of present calculation methods for air demand was conducted and a new form of calculation method for air demand related to unit width flow rate was established. The present prototype results can be used as a reference for similar engineering design, and to validate and verify numerical simulations as well as model tests.

ACS Style

Jijian Lian; Chunfeng Qi; Fang Liu; Wenjuan Gou; Shunqi Pan; QunAn Ouyang. Air Entrainment and Air Demand in the Spillway Tunnel at the Jinping-I Dam. Applied Sciences 2017, 7, 930 .

AMA Style

Jijian Lian, Chunfeng Qi, Fang Liu, Wenjuan Gou, Shunqi Pan, QunAn Ouyang. Air Entrainment and Air Demand in the Spillway Tunnel at the Jinping-I Dam. Applied Sciences. 2017; 7 (9):930.

Chicago/Turabian Style

Jijian Lian; Chunfeng Qi; Fang Liu; Wenjuan Gou; Shunqi Pan; QunAn Ouyang. 2017. "Air Entrainment and Air Demand in the Spillway Tunnel at the Jinping-I Dam." Applied Sciences 7, no. 9: 930.

Journal article
Published: 11 May 2017 in Applied Sciences
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Better understanding of the complex mechanical properties of ice is the foundation to predict the ice fail process and avoid potential ice threats. In the present study, uniaxial compressive strength and fracture mode of natural lake ice are investigated over moderate strain-rate range of 0.4–10 s−1 at −5 °C and −10 °C. The digital speckle correlation method (DSCM) is used for deformation measurement through constructing artificial speckle on ice sample surface in advance, and two dynamic load cells are employed to measure the dynamic load for monitoring the equilibrium of two ends’ forces under high-speed loading. The relationships between uniaxial compressive strength and strain-rate, temperature, loading direction, and air porosity are investigated, and the fracture mode of ice at moderate rates is also discussed. The experimental results show that there exists a significant difference between true strain-rate and nominal strain-rate derived from actuator displacement under dynamic loading conditions. Over the employed strain-rate range, the dynamic uniaxial compressive strength of lake ice shows positive strain-rate sensitivity and decreases with increasing temperature. Ice obtains greater strength values when it is with lower air porosity and loaded vertically. The fracture mode of ice seems to be a combination of splitting failure and crushing failure.

ACS Style

Jijian Lian; QunAn Ouyang; Xin Zhao; Fang Liu; Chunfeng Qi. Uniaxial Compressive Strength and Fracture Mode of Lake Ice at Moderate Strain Rates Based on a Digital Speckle Correlation Method for Deformation Measurement. Applied Sciences 2017, 7, 495 .

AMA Style

Jijian Lian, QunAn Ouyang, Xin Zhao, Fang Liu, Chunfeng Qi. Uniaxial Compressive Strength and Fracture Mode of Lake Ice at Moderate Strain Rates Based on a Digital Speckle Correlation Method for Deformation Measurement. Applied Sciences. 2017; 7 (5):495.

Chicago/Turabian Style

Jijian Lian; QunAn Ouyang; Xin Zhao; Fang Liu; Chunfeng Qi. 2017. "Uniaxial Compressive Strength and Fracture Mode of Lake Ice at Moderate Strain Rates Based on a Digital Speckle Correlation Method for Deformation Measurement." Applied Sciences 7, no. 5: 495.

Journal article
Published: 17 February 2017 in Applied Sciences
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The studies currently on soft galloping (SG) and hard galloping (HG) are scarce. In this study, SG and HG of spring-mounted triangular prisms in a water channel are investigated experimentally. A power take-off system (PTO), a spring system, additional weights, and different triangular prisms were used to achieve the variations in damping coefficient c, system stiffness K, oscillation mass m and section aspect ratios α, respectively. The present paper proves that the VIV (vortex-induced vibration) lower branch can be observed in the SG response. In SG response, VIV branches are incomplete while the galloping branch is complete, and galloping can be self-initiated only in the self-excited region. On the contrary, in HG response, VIV branches are complete, the galloping branch is incomplete, and galloping can only be initiated by external excitation at a velocity exceeding the critical velocity. As c and m increase, or K and α decrease, the oscillation mode of a triangular prism gradually transitions from SG to CG (critical galloping), and continues to HG. The amplitude in VIV branch is the main reason causing the onset of galloping in SG response. A critical damping coefficient cc, which is dependent on m, K and α, is proposed to predict the occurrences of SG, CG and HG. When c < cc, SG occurs; when c > cc, HG occurs; when c = cc, CG occurs.

ACS Style

Jijian Lian; Xiang Yan; Fang Liu; Jun Zhang; Quanchao Ren; Xu Yang. Experimental Investigation on Soft Galloping and Hard Galloping of Triangular Prisms. Applied Sciences 2017, 7, 198 .

AMA Style

Jijian Lian, Xiang Yan, Fang Liu, Jun Zhang, Quanchao Ren, Xu Yang. Experimental Investigation on Soft Galloping and Hard Galloping of Triangular Prisms. Applied Sciences. 2017; 7 (2):198.

Chicago/Turabian Style

Jijian Lian; Xiang Yan; Fang Liu; Jun Zhang; Quanchao Ren; Xu Yang. 2017. "Experimental Investigation on Soft Galloping and Hard Galloping of Triangular Prisms." Applied Sciences 7, no. 2: 198.

Research article
Published: 18 January 2017 in Shock and Vibration
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The energy in flow induced motion (FIM) was harnessed in recent years. In this study, the energy transfer ratio was derived to estimate the energy transference from the flow to the FIM. Then the FIM characteristics and energy transference of cylinders with different cross sections were experimentally investigated. The main findings are listed as follows. (a) Circular cylinders and diamond prisms both present a self-limited motion. The maximum amplitude ratio of circular cylinder is around 1~1.2 which is higher than that of diamond prism (0.4~0.5). (b) Triangle prisms and right square prisms present a self-unlimited motion. For triangle prism, amplitude ratio increases over 1.8; for right square prisms, amplitude ratio reaches 1.2. (c) The maximum transfer ratios of circular cylinder and triangle prism are 80% and 57%, respectively, which are much higher than those of other prisms, indicating that circular cylinder and triangle prism have better performances in energy transference. (d) The transfer ratio is strongly dependent on the damping and mass; higher damping or mass will promote a higher transfer ratio. (e) Beyond the critical transfer ratios, amplitude variation coefficients are around 10%~30% resulting in a better performance in stationarity.

ACS Style

Jijian Lian; Xiang Yan; Fang Liu; Jun Zhang. Analysis on Flow Induced Motion of Cylinders with Different Cross Sections and the Potential Capacity of Energy Transference from the Flow. Shock and Vibration 2017, 2017, 1 -19.

AMA Style

Jijian Lian, Xiang Yan, Fang Liu, Jun Zhang. Analysis on Flow Induced Motion of Cylinders with Different Cross Sections and the Potential Capacity of Energy Transference from the Flow. Shock and Vibration. 2017; 2017 ():1-19.

Chicago/Turabian Style

Jijian Lian; Xiang Yan; Fang Liu; Jun Zhang. 2017. "Analysis on Flow Induced Motion of Cylinders with Different Cross Sections and the Potential Capacity of Energy Transference from the Flow." Shock and Vibration 2017, no. : 1-19.

Journal article
Published: 10 November 2016 in Energies
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The flow induced vibration and energy extraction of an equilateral triangle prism elastically mounted in a water channel are investigated experimentally at different system damping ratios ζtotal with the constant oscillating mass Mosc and system stiffness K. A power take-off system with a variable damping function is developed. The translation-rotation equation of the vibration system deduced in the study indicates that the total oscillating mass includes the material mass, and the equivalent mass due to the rotation of the gears and rotor. Besides, increasing load resistance can result in a decrease in ζtotal when K and Mosc remain unchanged. The prism experiences, in turn, soft galloping, hard galloping 1 and hard galloping 2 with increasing ζtotal. As ζtotal increases up to 0.335, only the vortex-induced vibration is observed because the extremely high ζtotal prevents the prism from galloping. The response amplitude decreases with the increasing ζtotal. In addition, higher ζtotal promotes the galloping to start at a higher reduced velocity. The galloping characteristics of the prism, including large amplitude responses in an extremely large range of flow velocities, excellent vibration stationarity, and steady vibration frequencies, are beneficial for improving energy conversion. The prism can extract hydraulic energy for the flow velocity U > 0.610 m/s. The harnessed power Pout and the energy conversion efficiency ηout increase with increasing ζtotal in the galloping zone. The maximum Pout and ηout reach 53.56 W and 40.44%, respectively. The optimal system damping ratio for extracting energy is the maximum system damping ratio that the prism can overcome to experience stable galloping.

ACS Style

Jun Zhang; Fang Liu; Jijian Lian; Xiang Yan; Quanchao Ren. Flow Induced Vibration and Energy Extraction of an Equilateral Triangle Prism at Different System Damping Ratios. Energies 2016, 9, 938 .

AMA Style

Jun Zhang, Fang Liu, Jijian Lian, Xiang Yan, Quanchao Ren. Flow Induced Vibration and Energy Extraction of an Equilateral Triangle Prism at Different System Damping Ratios. Energies. 2016; 9 (11):938.

Chicago/Turabian Style

Jun Zhang; Fang Liu; Jijian Lian; Xiang Yan; Quanchao Ren. 2016. "Flow Induced Vibration and Energy Extraction of an Equilateral Triangle Prism at Different System Damping Ratios." Energies 9, no. 11: 938.