Hydraulic coupling vibration characteristics and control of hydropower station with upstream and downstream surge tanks

2022 ◽  
Vol 50 ◽  
pp. 101842
Author(s):  
Fulin Wu ◽  
Wencheng Guo ◽  
Shan Fu ◽  
Fangle Qu
Keyword(s):  
Vibration Characteristics ◽  
Hydropower Station ◽  
Coupling Vibration ◽  
Hydraulic Coupling ◽  
And Control

VIBRATION CHARACTERISTICS SIMULATION OF WRINKLED CIRCULAR ANNULUS-SHAPED GOSSAMER SPACE STRUCTURE

2008 ◽  
Vol 05 (01) ◽  
pp. 189-198 ◽  
Author(s):  
CHANGGUO WANG ◽  
XINGWEN DU ◽  
XIAODONG HE ◽  
GUOZHI SONG
Keyword(s):  
Structural Design ◽  
Membrane Structure ◽  
Space Structure ◽  
Vibration Characteristics ◽  
Structural Vibration ◽  
Space Structures ◽  
Deformation State ◽  
Wrinkling Analysis ◽  
Wrinkled Membrane ◽  
And Control

Ultra-lightweight Gossamer space structures have received the wide attention due to their small packaging volume and low launching cost. Since wrinkles are a common deformation state and the main failure mode of such structures and vibration behaviors are the major factor of the structural design and control, a better understanding of the wrinkling characteristics and the vibration behaviors of the wrinkled membrane structure is thus very essential and desirable. In this paper, a modal analysis method incorporating the wrinkling analysis is presented to simulate the vibration characteristics of a wrinkled membrane structure. The effects of the wrinkles on the structural vibration behaviors are also summarized in detail in the end.

scholarly journals Wireless Remote Controlled Electromagnet-Type Moving Microrobot

2014 ◽  
Vol 26 (1) ◽  
pp. 96-97
Author(s):  
Masahiro Isogai ◽  
Keyword(s):  
Control Method ◽  
Vibration Characteristics ◽  
Left And Right ◽  
The Difference ◽  
Remote Controller ◽  
And Control

We have been studying the mechanism and control method for electromagnet-type microrobots that have a volume of 1 cm3. Running straight andmaking turns with just a single electromagnet coil is the feature of the microrobot I developed. Newly developed microrobot is controlled by a wireless remote controller using the difference in the vibration characteristics of the left and right legs of the microrobot.

scholarly journals A Review of the Transient Process and Control for a Hydropower Station with a Super Long Headrace Tunnel

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2994 ◽  
Author(s):  
Wencheng Guo ◽  
Daoyi Zhu
Keyword(s):  
Design Optimization ◽  
Transient Process ◽  
Operating Conditions ◽  
Research Progress ◽  
Hydropower Station ◽  
Operation Conditions ◽  
Hydraulic Design ◽  
Headrace Tunnel ◽  
And Control ◽  
Hydropower Stations

The hydropower station with a super long headrace tunnel is a significant development type for hydropower energy. By constructing a super long headrace tunnel, the huge natural water fall head can be utilized to generate more electricity. With the development of hydropower energy, a hydropower station with a super long headrace tunnel becomes more and more competitive. Compared with a hydropower station with a short headrace tunnel, the transient process and control for a hydropower station with a super long headrace tunnel is much more complicated and becomes an intractable challenge. It is well known that the transient process and control is the basis of the design and operation of a hydropower station. To overcome the challenge of the transient process and control, much research has been carried out. This paper provides a systematic review on the latest research progress of the transient process and control for hydropower stations with a super long headrace tunnel. Firstly, two key issues for the transient process and control, i.e., hydraulic design optimization of the surge tank and operation control of unit, are illuminated. Secondly, for both single surge tanks and surge tanks with special types or combinations, the hydraulic design optimization methods are described. The most disadvantageous design and advantageous operation of surge tanks under combined operating conditions are discussed. Thirdly, the stability and regulation quality of the hydro-turbine governing system under isolated and grid-connected operation conditions are presented. Finally, some trends and recommendations for future research directions are made. A research thought for establishing the complete theory and application system of the transient process and control for hydropower stations with a super long headrace tunnel from the perspective of multi-slice and multi-scale is proposed.

Thermoelastic Coupling Vibration Characteristics of the Axially Moving Beam With Frictional Contact

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Guo Xu-Xia ◽  
Wang Zhong-Min
Keyword(s):  
Frictional Contact ◽  
Differential Quadrature Method ◽  
Contact Point ◽  
Normal Pressure ◽  
Vibration Characteristics ◽  
Axially Moving Beam ◽  
Thermoelastic Coupling ◽  
Coupling Vibration ◽  
Moving Beam ◽  
Axially Moving

The thermoelastic coupling vibration characteristics of the axially moving beam with frictional contact are investigated. The piecewise differential equation of motion for the axially moving beam in the thermoelastic coupling case and the continuous conditions at the contact point are established. The eigenequation is derived by the differential quadrature method, and the first order dimensionless complex frequencies of the simply supported axially moving beam under the coupled thermoelastic case are calculated. The effects of the dimensionless thermoelastic coupling factor, the dimensionless moving speed, the spring stiffness, the friction coefficient, and the normal pressure on the thermoelastic coupling vibration characteristics of the axially moving beam with frictional contact are discussed.

scholarly journals Microseismic Monitoring of Energy Changes in Deep Tunnels during the TBM Tunneling of the Jinping II Hydropower Station

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Duanyang Zhuang ◽  
Ke Ma ◽  
Chunan Tang ◽  
Zhengzhao Liang ◽  
Zhenwei Wang
Keyword(s):  
Control Method ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Rock Masses ◽  
Spatial And Temporal Patterns ◽  
Tunnel Section ◽  
Headrace Tunnel ◽  
Jinping Ii Hydropower Station ◽  
And Control

The TBM tunneling at the Jinping II hydropower station in Southwest China has received extensive concerns around the world because of its large engineering scale and the high rockburst risks faced in the tunnel advancement. The associated energy changes of rockbursts and control method for safe TBM tunneling are to be further investigated. A movable microseismic (MS) monitoring system was established to capture the MS events and rockbursts when the TBM excavated the headrace tunnel #1 at the Jinping II hydropower station. The spatial and temporal patterns of the energy changes in the tunnel rock masses were studied. Meanwhile, the evolution of a rockburst encountered in front of the TBM excavation face was revealed, and the performance of the top pilot tunnel method on the reduction of the rockburst risks in the headrace tunnel #1 was evaluated based on the energy changes of the surrounding rock masses. It can be concluded that energy accumulation and energy release firstly occurred in the surrounding rock masses at the southern end of the top pilot tunnel section of the headrace tunnel #1. Then, energy transference of the rock masses took place from the southern end to northwest of the top pilot tunnel giving rise to the occurrence of a moderate rockburst about 30 m in front of the tunnel. However, no rockbursts appeared when the TBM excavated through the top pilot tunnel section of the headrace tunnel #1. Therefore, the top pilot tunnel method really works in reducing the risks of rockbursts during the TBM tunneling in deep tunnels.

scholarly journals Analysis on Vibration Characteristics and Suppression Strategy of Vehicle Mounted GPR Detection Device for Tunnel Lining

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 309
Author(s):  
Yang Lei ◽  
Yong Zou ◽  
Tian Tian ◽  
Falin Qi ◽  
Bo Jiang
Keyword(s):  
High Speed ◽  
Control Program ◽  
Vibration Characteristics ◽  
Tunnel Lining ◽  
Railway Tunnel ◽  
Tunnel Detection ◽  
Adaptive Adjustment ◽  
And Control ◽  
Suppression Strategy

The GPR antenna is installed on the high-speed railway tunnel detection vehicle through the detection device to carry out non-contact nondestructive and rapid detection of the lining condition. Through simulation calculation and field vibration test data analysis, the vibration characteristics of the detection device are obtained. Vibration excitation is applied to GPR antennas to explore the amplitude-frequency sensitivity of echo signal affected by vibration when GPR detects tunnel lining, thus as to provide a basis for mechanism design and vibration control strategy. Through the optimization of the material properties, structural design, and control program of the detection device, the vibration frequency and amplitude of the detection device are optimized, the adaptive adjustment stability of the control system is improved, and the quality of GPR detection data is enhanced.

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