Development of a Vibroacoustic Noise Prediction Model for Multi-Layered Concentric Cylinders Under Electromagnetic Forced Vibration

Vibracoustic noise prediction models for electrically excited cylinders are used to predict the noise emissions for operating dry-type air-core reactors. These reactors are used to limit current and regulate voltage in electrical transmission and distribution grids. During operation, these reactors produce unwanted, electrically induced noise which is created by forced vibration due to the generated magnetic field from the electrical load being applied to the coil. The reactors designed with complex constructions having multiple winding coils will produce greater amounts of structure-borne sound. Given that these dynamically behave as multiple layers of concentric cylinders, cylindrical vibration theory can be used to predict their behaviour. The goal of this research was to construct and validate an innovative vibracoustic prediction model that accurately represents the mechanisms of the structure-borne noise generation of the reactor to accurately predict the noise emission levels during the design phase.For the Trench Limited Coil Operations, having the ability to accurately predict the noise produced by a reactor in the early design stage is critical to maintain a competitive edge in the competitive reactor market by ensuring that acoustic specifications are met. A review of the literature has shown very little work has been done to develop the science to accurately predict the noise generation for complex reactor construction with multiple winding coil packages. Also, the validation process for the current models do not consider a large frequency range and various electrical excitation frequencies. The novelty of this research is the construction of a cylindrical vibroacoustic noise prediction model for complex reactors of multiple winding packages in conjunction with the validation across a wide range of electrical excitation frequencies.In this dissertation, a detailed test and literature review is simultaneously presented in order to guide the development of an improved vibroacoustic model and to validate the noise prediction outcomes. A comprehensive literature review found various vibroacoustic models have been developed to represent the vibrational excitation of the reactor cylinder, and in turn compute the output noise emissions. Comprehensive noise and vibration testing of two prototype reactors with induced electrical excitation was conducted using CPB, FFT, directivity, noise source identification (NSI) and Modal analysis. From these analyses, the construction of the model was guided by considering the natural structural modes. In addition, a bank of noise emission data for validation of the proposed models was complied. Through the validation process of comparing the proposed vibroacoustic models with the collected reactor noise data, a recommended method for noise prediction was developed. The models coined the Cylindrical Vibroacoustic Model (both single and multiple layered models) were deemed to be the most effective and accurate method for reactor noise prediction. The methodology considers the cylindrical construction of the reactor with multiple layers of concentric cylinders and has been validated over a large electrical excitation frequency range. The outcome of this more versatile vibroacoustic model is the ability to better predict the noise emissions for complex reactor constructions having multiple winding coil packages

Meeting the challenges related to material issues in chemical industries

Reliable performance and profitability are two important requirements for any chemical industry. In order to achieve high level of reliability and excellent performance, several issues related to design, materials selection, fabrication, quality assurance, transport, storage, inputs from condition monitoring, failure analysis etc. have to be adequately addressed and implemented. Technology related to nondestructive testing and monitoring of the plant is also essential for precise identification of defect sites and to take appropriate remedial decision regarding repair, replacement or modification of process conditions. The interdisciplinary holistic approach enhances the life of critical engineering components in chemical plants. Further, understanding the failure modes of the components through the analysis of failed components throws light on the choice of appropriate preventive measures to be taken well in advance, to have a control over the overall health of the plant. The failure analysis also leads to better design modification and condition monitoring methodologies, for the next generation components and plants. At the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, a unique combination of the expertise in design, materials selection, fabrication, NDT development, condition monitoring, life prediction and failure analysis exists to obtain desired results for achieving high levels of reliability and performance assessment of critical engineering components in chemical industries. Case studies related to design, materials selection and fabrication aspects of critical components in nuclear fuel reprocessing plants, NDT development and condition monitoring of various components of nuclear power plants, and important failure investigations on critical engineering components in chemical and allied industries are discussed in this paper. Future directions are identified and planned approaches are briefly described

Aeronautical Engineering: A special bibliography with indexes, supplement 69

This bibliography lists 305 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1976

Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Nuclear Power Plants

This book covers various topics, from thermal-hydraulic analysis to the safety analysis of nuclear power plant. It does not focus only on current power plant issues. Instead, it aims to address the challenging ideas that can be implemented in and used for the development of future nuclear power plants. This book will take the readers into the world of innovative research and development of future plants. Find your interests inside this book

Nuclear Power

The world of the twenty first century is an energy consuming society. Due to increasing population and living standards, each year the world requires more energy and new efficient systems for delivering it. Furthermore, the new systems must be inherently safe and environmentally benign. These realities of today's world are among the reasons that lead to serious interest in deploying nuclear power as a sustainable energy source. Today's nuclear reactors are safe and highly efficient energy systems that offer electricity and a multitude of co-generation energy products ranging from potable water to heat for industrial applications. The goal of the book is to show the current state-of-the-art in the covered technical areas as well as to demonstrate how general engineering principles and methods can be applied to nuclear power systems

NDE: An effective approach to improved reliability and safety. A technology survey

Technical abstracts are presented for about 100 significant documents relating to nondestructive testing of aircraft structures or related structural testing and the reliability of the more commonly used evaluation methods. Particular attention is directed toward acoustic emission; liquid penetrant; magnetic particle; ultrasonics; eddy current; and radiography. The introduction of the report includes an overview of the state-of-the-art represented in the documents that have been abstracted