Bøger af Ravi Rajamani

Condition-Based Maintenance in Aviation: The History, The Business and The Technology describes the history and practice of Condition-Based Maintenance (CBM) systems by showcasing ten technical papers from the archives of SAE International, stretching from the dawn of the jet age down to the present times.By scientifically understanding how different components degrade during operations, it is possible to schedule inspections, repairs, and overhauls at appropriate intervals so that any incipient failure can be detected well in advance.Today, this includes more sensors and analytics so that periodic inspections are replaced by automated "e;continuous"e; inspections, and analytical methods that detect imminent failures and predict degradation issues more economically and efficiently.Similar concepts are also being developed for delivering prognostics functions, such as tracking of remaining useful life (RUL) of life-limited parts in aircraft engines.The discipline within CBM that deals with this is called prognostics and health management (PHM), which covers all aspects of diagnostics and prognostics, including modeling of systems and subsystems, sensing, data transmission, storage and retrieval, analytical methods, and decision making.Traditionally, nondestructive testing (NDT) methods have been employed during the major airplane checks to assess structural damage. These techniques are enhanced with in- situ sensing techniques that can continuously monitor aircraft structures and report on their health.The move to condition-based assessment of maintenance needs to be balanced by the assurance that safety is not compromised, that initial cost of new equipment is amortized by the savings, and that regulatory authorities are on board with any modifications to the planned maintenance schedule. The trend is clearly to include more CBM functions into Maintenance, Repair and Overhaul (MRO) processes so better cost control can be achieved without ever comprising passenger safety.

The use of electric propulsion in aeroplanes is not a new phenomenon. However, it is only recently that it has taken off in a concrete manner with a viable commercial future. This volume reviews the history of this field, discusses the key underlying technologies, and describes how the future for these technologies will likely unfold.

The "holy grail" for prognostics and health management (PHM) professionals in the aviation sector is to have integrated vehicle health management (IVHM) systems incorporated into standard aircraft maintenance policies. Such a change from current aerospace industry practices would lend credibility to this field by validating its claims of reducing repair and maintenance costs and, hence, the overall cost of ownership of the asset. Ultimately, more widespread use of advanced PHM techniques will have a positive impact on safety and, for some cases, might even allow aircraft designers to reduce the weight of components because the uncertainty associated with estimating their predicted useful life can be reduced. We will discuss how standard maintenance procedures are developed, who the various stakeholders are, and - based on this understanding - outline how new PHM systems can gain the required approval to be included in these standard practices. There have been a few limited successes in this field already, and we will discuss the lessons learned in developing these systems. Finally, we will review the progress that the structural health management (SHM) community has made, and continues to make, to change the way the industry regards automated SHM systems.NOTE: SAE EDGE¿ Research Reports are intended to identify and illuminate key issues in emerging, but still unsettled, technologies of interest to the mobility industry. The goal of SAE EDGE¿ Research Reports is to stimulate discussion and work in the hope of promoting and speeding resolution of identified issues. SAE EDGE¿ Research Reports are not intended to resolve the issues they identify or close any topic to further scrutiny.

Fundamentals of Electric Aircraft was developed to explain what the electric aircraft stands for by offering an objective view of what can be expected from the giant strides in innovative architectures and technologies enabling aircraft electrification. Through tangible case studies, a deep insight is provided into this paradigm shift cutting across various aircraft segments from General Aviation to Large Aircraft. Addressing design constraints and timelines foreseen to reach acceptable performance and maturity levels, Fundamentals of Electric Aircraft puts forward a general view of the progress made to date and what to expect in the years to come. Drawing from the expertise of four industry veterans, Pascal Thalin (editor), Ravi Rajamani, Jean-Charles Mare and Sven Taubert (contributors), it addresses futuristic approaches but does not depart too far from the operational down-to-earth realities of everyday business. Fundamentals of Electric Aircraft also offers analyses on how performance enhancements and fuel burn savings may bring more value for money as long as new electric technologies deliver on their promises.