Simulating the signature produced by a single airgun under real gas conditions

作     者：王风帆 刘怀山 

作者机构：中国海洋大学海底科学与探测技术教育部重点实验室青岛266100 

出 版 物：《Applied Geophysics》 (应用地球物理（英文版）)

年 卷 期：2014年第11卷第1期

页      面：80-88,117页

核心收录：

学科分类：07[理学] 

基　　金：This research is financially supported by the National Science Foundation Project (Grant No. 41176077  41230318) and the National 973 Program (Grant No. 2009CB219505) 

主　　题：Van der Waals gas port throttling bubble rise heat transition surface reflection 

摘      要：Models that simulate the signature of single airguns form the basis for modeling the signals of airgun arrays. Most of the existing models assume that the air inside the produced bubble is ideal gas, which may lead to errors because of the high operating pressure of the airguns. In this study, we propose a model that precisely simulates the signals of single airguns by applying the Van der Waals equation based on the Ziolkowski algorithm. We also consider a thermodynamically open quasistatic system, the heat transition between water and gas, the throttling effect of the port and the bubble rise, and the effect of the sea surface. Modeling experiments show that(1) the energy of the source increases and the signal-tonoise ratio of the signature wavelet decreases with increasing seawater temperature,(2) the reflection coefficient of the sea surface under the actual state and depth of the source affects the notch caused by the surface reflection,(3) the computed signature with the proposed model is very close to the actual data, and(4) the proposed model accurately simulates the signature of single airguns.