Wave-soil-pipe coupling effect on submarine pipeline on-bottom stability

2001 ◽  
Vol 17 (1) ◽  
pp. 86-96 ◽  
Author(s):  
Gu Xiaoyun ◽  
Gao Fuping ◽  
Pu Qun
Keyword(s):  
Coupling Effect ◽  
Submarine Pipeline ◽  
Pipe Coupling ◽  
Soil Pipe

Impulsive Responses of a Circular Cylindrical Shell Subjected to Waterhammer Waves

1991 ◽  
Vol 113 (4) ◽  
pp. 517-523 ◽  
Author(s):  
T. Adachi ◽  
S. Ujihashi ◽  
H. Matsumoto
Keyword(s):  
Cylindrical Shell ◽  
Perfect Fluid ◽  
Analytical Solutions ◽  
Shell Theory ◽  
Coupling Effect ◽  
Circular Cylindrical Shell ◽  
Inertia Effect ◽  
Pipe Coupling ◽  
Rough Approximation ◽  
Coupled Theory

The impulsive responses of semi-finite and finite pipes filled with fluid are analyzed in order to clarify the validity of Joukowsky’s theory and the fluid-pipe coupling effect. In the analysis, Flu¨gge’s dynamic bending shell theory and the potential theory of compressible perfect fluid are used. The analytical solutions in Laplace transformed domain are obtained. The inversion of the solutions is performed numerically using the algorithm of FFT. When a pipe is fairly long, it is shown that the result of Joukowsky’s theory which has no pipe inertia effect approximately agrees with that of the coupled theory. When a pipe is short, Joukowsky’s theory shows rough approximation of the responses. The response of the uncoupled theory with the inertia of a pipe is different from that of the coupled theory for both long and short pipes.

Coupling Effect of Vortex-Induced Vibration of a Submarine Pipeline and Local Scour Under Steady Current

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Qi Zhang ◽  
Xiang-Lian Zhou ◽  
Xiao-He Xia ◽  
Wan-Ling Li ◽  
Shuo Zhang
Keyword(s):  
Moving Objects ◽  
Coupling Effect ◽  
Diameter Ratio ◽  
Local Scour ◽  
Submarine Pipeline ◽  
Steady Current ◽  
Pipeline Vibration ◽  
Gmo Model ◽  
Fully Coupled ◽  
Good Agreement

The dynamic interaction between pipeline vibration and local scour is investigated numerically. The sediment scour model is adopted to calculate the local scour below pipeline. The general moving objects (GMO) model fully coupled with the fluids is established to simulate the pipeline vibration. The present results are consistent with the previous experimental results and show good agreement. The scour depth and scour hole scale are closely related to the amplitude of pipeline vibration. The effects of initial gap-to-diameter ratio, reduced velocity, and pipeline diameter on the local scour and pipeline vibration are investigated.

An hourglass-type electromagnetic isolator with negative resistance electromagnetic shunt circuit

2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang
Keyword(s):  
Vibration Isolation ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Negative Resistance ◽  
Isolation System ◽  
Amplitude Vibration ◽  
Vibration Responses ◽  
The Stability ◽  
Isolation Performance ◽  
Shunt Circuit

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.

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