Noise and Vibration Control Techniques for the U. S. Navy 3000-LT Surface-Effect Ship

1980 ◽  
Vol 17 (01) ◽  
pp. 16-28
Author(s):  
Gary L. Fox

The Navy 3000-LT Surface-Effect Ship (3KSES) Program has provided a major advance in the development of high-performance ship technology in many areas. One such area is noise and vibration control techniques applicable to lightweight/high-power vehicles. New analytical methods have been evolved and substantial testing accomplished to support certain theoretical aspects of the analysis or to provide the necessary empirical data. This paper presents a summary of the technical approach used in the 3KSES Noise and Vibration Analysis, a description of the systems installed to achieve the desired acoustical control, and comparison of the predicted ship noise and vibration environment with the Navy specification. The noise sources considered are those related to the major machinery, that is, the gas turbine engines, the large lift fans, and the waterjet propulsors.

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4214
Author(s):  
Kranthi Kumar Maniam ◽  
Shiladitya Paul

The increased demand for high performance gas turbine engines has resulted in a continuous search for new base materials and coatings. With the significant developments in nickel-based superalloys, the quest for developments related to thermal barrier coating (TBC) systems is increasing rapidly and is considered a key area of research. Of key importance are the processing routes that can provide the required coating properties when applied on engine components with complex shapes, such as turbine vanes, blades, etc. Despite significant research and development in the coating systems, the scope of electrodeposition as a potential alternative to the conventional methods of producing bond coats has only been realised to a limited extent. Additionally, their effectiveness in prolonging the alloys’ lifetime is not well understood. This review summarises the work on electrodeposition as a coating development method for application in high temperature alloys for gas turbine engines and discusses the progress in the coatings that combine electrodeposition and other processes to achieve desired bond coats. The overall aim of this review is to emphasise the role of electrodeposition as a potential cost-effective alternative to produce bond coats. Besides, the developments in the electrodeposition of aluminium from ionic liquids for potential applications in gas turbines and the nuclear sector, as well as cost considerations and future challenges, are reviewed with the crucial raw materials’ current and future savings scenarios in mind.


Author(s):  
J. M. Lane

While the radial in-flow turbine has consistently demonstrated its capability as a high-performance component for small gas turbine engines, its use has been relegated to lower turbine-inlet-temperature cycles due to insurmountable problems with respect to the manufacturing of radial turbine rotors with internal cooling passages. These cycle temperature limitations are not consistent with modern trends toward higher-performance, fuel-conservative engines. This paper presents the results of several Army-sponsored programs, the first of which addresses the performance potential for the high-temperature radial turbine. The subsequent discussion presents the results of two successful programs dedicated to developing fabrication techniques for internally cooled radial turbines, including mechanical integrity testing. Finally, future near-term capabilities are projected.


Author(s):  
Hooshang Heshmat ◽  
James F. Walton

Abstract To achieve high power density Gas Turbine Engines (GTEs), R&D efforts have strived to develop machines that spin faster and run hotter. One method to achieve that goal is to use high temperature capable foil bearings. In order to successfully integrate these advanced foil bearings into GTE systems, a theoretical understanding of both bearing and rotor system integration is essential. Without a fundamental understanding and sound theoretical modeling of the foil bearing coupled with the rotating system such an approach would prove application efforts fruitless. It is hoped that the information provided in this paper will open up opportunistic doors to designs presently thought to be impossible. In this paper an attempt is made to describe how an advanced foil bearing is modeled for extreme high temperature operation in high performance turbomachinery including GTEs, Supercritical CO2 turbine generators and others. The authors present the advances in foil bearing capabilities that were crucial to achieving high temperature operation. Achieving high performance in a compliant foil bearing under the wide extremes of operating temperatures, pressures and speeds, requires a bearing system design approach that accounts for the highly interrelated compliant surface foil bearing elements such as: the structural stiffness and frictional characteristics of the underlying compliant support structure across the operating temperature and pressure spectrum; and the coupled interaction of the structural elements with the hydrodynamic pressure generation. This coupled elasto-hydrodynamic-Finite Element highly non-linear iterative methodology will be used by the authors to present a series of foil bearing design evaluations analyzing and modeling the foil bearing under extreme conditions. The complexity of the problem of achieving foil bearing system operation beyond 870°C (1600°F) requires as a prerequisite the attention to the tribological details of the foil bearing. For example, it is necessary to establish how both the frictional and viscous damping coefficient elements as well as the structural and hydrodynamic stiffness are to be combined. By combining these characteristics the influence of frictional coefficients of the elastic and an-elastic materials on bearing structural stiffness and hence the bearing effective coupled elasto-hydrodynamic stiffness coefficients will be shown. Given that the bearing dynamic parameters — stiffness and damping coefficients — play a major role in the control of system dynamics, the design approach to successfully integrate compliant foil bearings into complex rotating machinery systems operating in extreme environments is explored by investigating the effects of these types of conditions on rotor-bearing system dynamics. The proposed rotor/bearing model is presented to describe how system dynamics and bearing structural properties and operating characteristics are inextricably linked together in a manner that results in a series separate but intertwined iterative solutions. Finally, the advanced foil bearing modeling and formulation in connection with resulting rotor dynamics of the system will be carried out for an experimental GTE simulator test rig. The analytical results will be compared with the experiments as presented previously to demonstrate the effectiveness of the developed method in a real world application [1].


1967 ◽  
Vol 89 (2) ◽  
pp. 177-185 ◽  
Author(s):  
M. J. T. Smith ◽  
M. E. House

The noise sources from gas turbine engines are defined and their radiation patterns identified from test results. Examination of single-stage and full-scale engine compressor noise measurements leads to a prediction technique being evolved for inlet and efflux levels.


1976 ◽  
Vol 98 (4) ◽  
pp. 619-625
Author(s):  
K. H. Pech ◽  
N. L. Downing

Fuel pumps and metering systems are becoming more complex and expensive to meet the high performance requirements of advanced gas turbine engines. A simple, inlet throttled, centrifugal pump integrated with a retracting vane starting element provides the potential for a reliable, high performance design capable of reducing the cost, weight, and temperature rise of the fuel system. This paper presents the results of recent efforts to develop the retracting vane element and to integrate it with a vapor core centrifugal pump in order to meet the fuel performance and functional requirements of an advanced gas turbine main fuel pump.


Author(s):  
R. E. Barnhart

Metallic and ceramic coatings enhance the quality of today’s gas turbine engines by enabling them to run longer and by increasing their reliability and efficiency of operation. Coatings give design engineers more latitude in their choice of materials for high-performance applications. Discussed here are the characteristics of coatings produced by three different means: detonation-gun process, plasma process, and diffusion process. By considering the following three parameters: (a) the nature of wear and corrosion problems in gas turbine engines, (b) the results of coated components in commercial service, and (c) the cost savings attributable to coatings, we can develop guidelines for even more effective use of coatings in the future.


Author(s):  
Michael J. Roemer ◽  
Carl S. Byington ◽  
Gregory J. Kacprzynski ◽  
George Vachtsevanos

The DoD has various vehicle platforms powered by high performance gas turbine engines that would benefit greatly from predictive health management technologies that can detect, isolate and assess remaining useful life of critical line replaceable units (LRUs) or subsystems. In order to meet these needs for next generation engines, dedicated prognostic algorithms must be developed that are capable of operating in an autonomous and real-time engine health management system software architecture that is distributed in nature. This envisioned prognostic and health management system should allow engine-level reasoners to have visibility and insight into the results of local diagnostic and prognostic technologies implemented down at the LRU and subsystem levels. To accomplish this effectively requires an integrated suite of prognostic technologies that can be applied to critical engine systems and can capture fault/failure mode propagation and interactions that occur in these systems, all the way up through the engine and eventually vehicle level. In the paper, the authors will present a generic set of selected prognostic algorithm approaches that can be applied to gas turbine engines, as well as provide an overview of the required reasoning architecture needed to integrate the prognostic information across the engine.


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