There are many access ends and information asymmetry in the management of offshore platform production facility personnel information. In the actual business, the problem is decomposed and a multi-layer logical archit...There are many access ends and information asymmetry in the management of offshore platform production facility personnel information. In the actual business, the problem is decomposed and a multi-layer logical architecture is selected to design and develop the POB plan management module applicable to offshore platform facilities. The main functions of this module include task management, facility management, area management, sea-going unit management, plan management, report management, authority control, and comprehensive query. It can efficiently solve on-site business problems and improve the efficiency of POB plan management for various professionals on land and at sea. In actual use, the module can well assist in completing POB plan management tasks and improve work efficiency.展开更多
The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound...The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound pressure spectrum model is presented to describe its non-cavitation noise with application of generalized acoustic analogy method, the modulation mechanism is expressed with the improvement of sound pressure model. The power spectrum and modulation spectrum are presented by numerical simulation. Theoretical analysis and nu- merical simulation results are verified by the cavitation tunnel experiment. The modulation model of counter-rotation propeller is beneficial to the prediction modulation characteristics and identification of underwater high-speed vehicles.展开更多
文摘There are many access ends and information asymmetry in the management of offshore platform production facility personnel information. In the actual business, the problem is decomposed and a multi-layer logical architecture is selected to design and develop the POB plan management module applicable to offshore platform facilities. The main functions of this module include task management, facility management, area management, sea-going unit management, plan management, report management, authority control, and comprehensive query. It can efficiently solve on-site business problems and improve the efficiency of POB plan management for various professionals on land and at sea. In actual use, the module can well assist in completing POB plan management tasks and improve work efficiency.
基金supported by the National Natural Science Foundation of China(11704345)the Key Laboratory of Science and Technology for National Defence Foundation(9140C290304140C29133)
文摘The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound pressure spectrum model is presented to describe its non-cavitation noise with application of generalized acoustic analogy method, the modulation mechanism is expressed with the improvement of sound pressure model. The power spectrum and modulation spectrum are presented by numerical simulation. Theoretical analysis and nu- merical simulation results are verified by the cavitation tunnel experiment. The modulation model of counter-rotation propeller is beneficial to the prediction modulation characteristics and identification of underwater high-speed vehicles.
