Marine spark sources are widely used in high-resolution marine seismic surveys.The characteristic of a wavelet is a critical part in seismic exploration;thus,the formation and numerical simulation of spark source wave...Marine spark sources are widely used in high-resolution marine seismic surveys.The characteristic of a wavelet is a critical part in seismic exploration;thus,the formation and numerical simulation of spark source wavelets should be explored.In studies on spark source excitation,the acoustic field generated by the interaction between bubbles constitutes the near-field wavelet of a source.Therefore,this interaction should be revealed by studying complex multibubble motion laws.In this study,actual discharge conditions were combined to derive the multibubble equation of motion.Energy conservation,ideal gas equation,and environmental factors in the discharge of spark source wavelets were studied,and the simulation method of an ocean spark source wavelet was established.The accuracy of the simulation calculation method was verified through a comparison of indoor-measured signals using three electrodes and the spark source wavelet obtained in the field.Results revealed that the accuracy of the model is related to the number of electrodes.The fewer the number of electrodes used,the lower will be the model's accuracy.This finding is attributed to the statistical hypothesis factor introduced to eliminate the coupling term of the interaction of the multibubble motion equation.This study presents a method for analyzing the wavelet characteristics of an indoor-simulated spark source wavelet.展开更多
Multibubble formation is a common phenomenon.In this paper,a model of a multibubble accounting for heat transfer,phase change,and bubblebubble interaction through bubble-induced pressure waves is proposed.Numerical si...Multibubble formation is a common phenomenon.In this paper,a model of a multibubble accounting for heat transfer,phase change,and bubblebubble interaction through bubble-induced pressure waves is proposed.Numerical simulations are conducted using this model to investigate the dynamic behavior,energy conversion over each cycle,mass damping of one bubble in a synchronized and same-size multibubble,and the Bjerknes force between two bubbles in a multibubble.Here,one cycle is defined as the interval between two adjacent time points corresponding to peak radii,and a nondimensional parameter y representing the interaction strength is defined.The model is validated,and a formulation of the collapse time accounting for bubble-bubble interaction is derived.Bubble-bubble interaction extends the collapse time and increases the peak temperature and pressure of the collapsing bubble during its first cycle.On the one hand,the results reveal attenuation of energy conversion due to pressure work,thermal conduction,and phase change over each cycle,as well as mass damping of one bubble in a multibubble.It is found that most of this attenuation occurs during the first three or four cycles.On the other hand,energy conversions due to pressure work and phase change over the first cycle increase with increasing y,but that due to thermal conduction over this cycle decreases.Furthermore,the Bjerknes force is also subject to damping similar to that of energy conversion over each cycle.展开更多
基金supported by the Geological Survey of China(No.DD20191003)the National Key Research and Development Plan(No.2016YFC0303901)。
文摘Marine spark sources are widely used in high-resolution marine seismic surveys.The characteristic of a wavelet is a critical part in seismic exploration;thus,the formation and numerical simulation of spark source wavelets should be explored.In studies on spark source excitation,the acoustic field generated by the interaction between bubbles constitutes the near-field wavelet of a source.Therefore,this interaction should be revealed by studying complex multibubble motion laws.In this study,actual discharge conditions were combined to derive the multibubble equation of motion.Energy conservation,ideal gas equation,and environmental factors in the discharge of spark source wavelets were studied,and the simulation method of an ocean spark source wavelet was established.The accuracy of the simulation calculation method was verified through a comparison of indoor-measured signals using three electrodes and the spark source wavelet obtained in the field.Results revealed that the accuracy of the model is related to the number of electrodes.The fewer the number of electrodes used,the lower will be the model's accuracy.This finding is attributed to the statistical hypothesis factor introduced to eliminate the coupling term of the interaction of the multibubble motion equation.This study presents a method for analyzing the wavelet characteristics of an indoor-simulated spark source wavelet.
基金support of the National Natural Science Foundation of China(Grant No.52179094)the Key Research and Development Project of Zhejiang Province(Grant No.2024C01117)the Key Research and Development Project of Hangzhou,China(Grant No.2023SZD0041).
文摘Multibubble formation is a common phenomenon.In this paper,a model of a multibubble accounting for heat transfer,phase change,and bubblebubble interaction through bubble-induced pressure waves is proposed.Numerical simulations are conducted using this model to investigate the dynamic behavior,energy conversion over each cycle,mass damping of one bubble in a synchronized and same-size multibubble,and the Bjerknes force between two bubbles in a multibubble.Here,one cycle is defined as the interval between two adjacent time points corresponding to peak radii,and a nondimensional parameter y representing the interaction strength is defined.The model is validated,and a formulation of the collapse time accounting for bubble-bubble interaction is derived.Bubble-bubble interaction extends the collapse time and increases the peak temperature and pressure of the collapsing bubble during its first cycle.On the one hand,the results reveal attenuation of energy conversion due to pressure work,thermal conduction,and phase change over each cycle,as well as mass damping of one bubble in a multibubble.It is found that most of this attenuation occurs during the first three or four cycles.On the other hand,energy conversions due to pressure work and phase change over the first cycle increase with increasing y,but that due to thermal conduction over this cycle decreases.Furthermore,the Bjerknes force is also subject to damping similar to that of energy conversion over each cycle.
