Review of advances on longitudinal vibration of submarine propulsion shafting and its vibration reduction technology

Analyzed the formation mechanism of longitudinal vibration of the submarine propulsion shafting system, and introduced its existing vibration control technology. The content included the improvement design of propulsion shafting system, new types of thrust bearing, composite material shaft, dynamic vibration absorber, phonon crystal band gap damping and relative active control technology. A new method for the application of metal rubber technology in thrust bearing was put forward, which provided a new idea for the research work in the future

A review of the dynamic analysis of axial vibrations in marine propulsion shafting system due to propeller excitation

Over the past decades, the attenuation of axial vibration due to propeller excitation has long been a complex problem due to the coupling dynamics of the propeller-shafting system. As axial vibration is often the cause of fatigue damage to the propulsion shaft components as well as the root cause to acoustical radiation along a hull of a ship, there has been continuous interest in understanding the complex dynamic characteristics of the coupled propeller-shaft system and the methods to suppress the axial vibration in the system. Therefore, several studies have been conducted to solve this vibration problem on the longitudinal axis of the marine propulsion shafting system. This paper aims to provide the theoretical foundations of this problem by reviewing the modelling techniques of this coupled dynamic problem and cover the vibration reduction strategies that are proposed by the cited studies

China Maritime Report No. 30: A Brief Technical History of PLAN Nuclear Submarines

After nearly 50 years since the first Type 091 SSN was commissioned, China is finally on the verge of producing world-class nuclear-powered submarines. This report argues that the propulsion, quieting, sensors, and weapons capabilities of the Type 095 SSGN could approach Russia’s Improved Akula I class SSN. The Type 095 will likely be equipped with a pump jet propulsor, a freefloating horizontal raft, a hybrid propulsion system, and 12-18 vertical launch system tubes able to accommodate anti-ship and land-attack cruise missiles. China’s newest SSBN, the Type 096, will likewise see significant improvements over its predecessor, with the potential to compare favorably to Russia’s Dolgorukiy class SSBN in the areas of propulsion, sensors, and weapons, but more like the Improved Akula I in terms of quieting. If this analysis is correct, the introduction of the Type 095 and Type 096 would have profound implications for U.S. undersea security.https://digital-commons.usnwc.edu/cmsi-maritime-reports/1029/thumbnail.jp

Nonlinear Giant Magnetostrictive Actuator and Its Application in Active Control

The giant magnetostrictive actuator has great use in vibration control, but the linear model cannot fully describe its dynamic characteristics. In this chapter, based on the domain wall theory and piezomagnetic theory, a hysteresis nonlinear model is established to fully describe the actuator dynamic characteristics. In combination with the regularisation method, a sliding mode controller has been designed, and the giant magnetostrictive actuator is also studied in the application of active control. Experimental results show that the hysteresis nonlinear model proposed in the chapter can fully describe the actuator’s dynamic characteristics in a wider frequency band and the active control also has a much better isolation effect than the passive vibration; it can significantly attenuate the external incentives

Marine Power Systems

Marine power systems have been designed to be a safer alternative to stationary plants in order to adhere to the regulations of classification societies. Marine steam boilers recently achieved 10 MPa pressure, in comparison to stationary plants, where a typical boiler pressure of 17 MPa was the standard for years. The latest land-based, ultra-supercritical steam boilers reach 25 MPa pressure and 620 °C temperatures, which increases plant efficiency and reduces fuel consumption. There is little chance that such a plant concept could be applied to ships. The reliability of marine power systems has to be higher due to the lack of available spare parts and services that are available for shore power systems. Some systems are still very expensive and are not able to be widely utilized for commercial merchant fleets such as COGAS, mainly due to the high cost of gas turbines. Submarine vehicles are also part of marine power systems, which have to be reliable and accurate in their operation due to their distant control centers. Materials that are used in marine environments are prone to faster corrosive wear, so special care also should be taken in this regard. The main aim of this Special Issue is to discuss the options and possibilities of utilizing energy in a more economical way, taking into account the reliability of such a system in operation

Shared Technology Transfer Program

The program established a collaborative process with domestic industries for the purpose of sharing Navy-developed technology. Private sector businesses were educated so as to increase their awareness of the vast amount of technologies that are available, with an initial focus on technology applications that are related to the Hydrogen, Fuel Cells and Infrastructure Technologies (Hydrogen) Program of the U.S. Department of Energy. Specifically, the project worked to increase industry awareness of the vast technology resources available to them that have been developed with taxpayer funding. NAVSEA-Carderock and the Houston Advanced Research Center teamed with Nicholls State University to catalog NAVSEA-Carderock unclassified technologies, rated the level of readiness of the technologies and established a web based catalog of the technologies. In particular, the catalog contains technology descriptions, including testing summaries and overviews of related presentations

1995 BRAC Commission

Naval Surface Warfare Centers - Correspondence and Briefings (1 of 3). Box 245, N-003

Aeronautical Engineering: A special bibliography with indexes, supplement 54

This bibliography lists 316 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1975

1995 BRAC Commission

ARD Detachment, Naval Surface Warfare Center Carderock Division, Naval Surface Warfare Center Carderock Division Detachment Annapolis, Naval Surface Warfare Center Carderock Philadelphia Detachment. Features and capabilities, special facilities and equipment. Box 181, L-113