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Dalian, China

Tian H.-D.,Unit 91439 | Jin L.-A.,Dalian Naval Academy | Wang Y.,Dalian Naval Academy | Chi W.,Dalian Naval Academy
Binggong Xuebao/Acta Armamentarii | Year: 2011

In order to analyze the bubble distribution in ship wake theoretically, the motion characteristics and influence factors of the single bubble are studied. The strong-coupling interaction between bubble rising velocity and mass-transfer velocity is considered emphatically, and a dynamic model to describe the whole process of bubble motion in the ship wake is established. Based on the model and statistical analysis, a convenient method to calculate the bubble residence time, relative number density and size distribution is proposed. The simulation results coincide with the experimental data better. Source

Jin H.,Unit 91439 | Gao H.-P.,Unit 91439 | Peng Y.-X.,Harbin Engineering University | Guan Q.-L.,Unit 91439
Binggong Xuebao/Acta Armamentarii | Year: 2015

The bubbles caused by near-field underwater explosion produce high velocity jet toward the structure under the action of Bjerknes force and buoyancy. Since the bubble impulsion is affected by object surface, its influence on the structure is not evident, the loads mainly consist of shock waves and bubble jet. The shape of bubble jet is equal to water jet. The load of bubble jets is obtained based on the water hammer theory. Meanwhile, the shock wave load is drawn from the Geers & Hunter semi-analytical and theoretical solution. Finally the total load is applied on the near-field structure to get the responses of ship structure based on acoustic structure coupling method, and then get the damage characteristics of warship. © 2015, China Ordnance Society. All right reserved. Source

Zhang Y.-K.,Unit 91439 | Wang S.-L.,Unit 91439 | Shen X.-L.,Unit 91439
Binggong Xuebao/Acta Armamentarii | Year: 2015

The free vibration of double wall grillage is studied by using theoretical analysis method. First of all, the double-wall grillage structure is transformed into the orthotropic plate model, and then the free vibration problem of simply supported orthotropic plate is solved theoretically. In the example, the free vibration of double-wall grillage with simply supported orthotropic plate is solved. The correctness of the proposed method is proved by comparing with the finite element simulation results. © 2015, China Ordnance Society. All right reserved. Source

Zhang S.-H.,Unit 91439 | Tian H.-D.,Unit 91439 | Shen X.-L.,Unit 91439 | Jin H.,Unit 91439
Binggong Xuebao/Acta Armamentarii | Year: 2013

High-speed camera is an important way to research the underwater explosion, while the protecting structure for the camera tends to move under shock wave and bubble impulse caused by underwater explosion. A protecting structure is designed to satisfy the stable demand of high-speed camera system. The distribution of flow field surrounding it is calculated using Fluent software, and the movement characteristics are analyzed. The results show that the displacement of designed structure is less than 5 cm with 60 kg TNT and shock factor of 0.5, and the stability can satisfy the demand of underwater explosions. Source

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