Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"High bypass-ratio"”.
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Numerical characterization of rotor broadband noise sources in a high bypass-ratio turbofan
… par des simulations numériques dans la configuration réaliste du rotor de turboréacteur à fort taux de dilution. Elle comprend la simulation aux grandes échelles (LES) modélisée et résolue en paroi, qui est capable de résoudre la plupart du spectre de turbulence et capturer les sources de bruit …
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Propulsion system concepts for silent aircraft
… The propulsion system concepts of ultra-high bypass ratio turbofan engines, a distributed propulsion system, and silent engine air-brakes are evaluated in light of their noise signatures and propulsion system performance. These propulsion system concepts are assessed using simple analytic …
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Design of a model propulsor for a boundary layer ingesting aircraft
… single-stage propulsors represent the ultra-high bypass ratio turbofan engines on a full-scale conceptual aircraft previously designed at MIT. Powered models will use these propulsors in both podded and boundary layer ingesting configurations to allow back-to-back assessment of BLI benefit. …
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Accounting for system level interaction in knowledge management initiatives
An overview of the operation of a modem, high bypass ratio, dual spool turbofan engine is presented to identify the multitude of system level interactions that must be considered when developing such an engine. The Design Structure Matrix (DSM) is used to demonstrate how it maps these relationships …
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Assessing selected technologies and operational strategies for improving the environmental performance of future aircraft
… This work assesses selected technologies and operational procedures aimed at improving the environmental performance of future airplanes. Two different studies are presented: estimating turbine durability benefits from jet engine water injection and evaluating improvements in fuel burn and …
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System integration analysis of a large commercial aircraft engine
… and demonstrate a method, called a System Integration Analysis, to produce a comprehensive understanding of the activities Integrated Product Teams (IPTs) perform in designing and developing a large complex product or system. The methodology is applied to an existing product or system whose …
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Development of an engine model for an integrated aircraft design tool
… of a new engine weight surrogate model and High Pressure Compressor (HPC) polytropic efficiency correction for the propulsion module in the Transport Aircraft OPTtimization (TASOPT) code. The goal of this work is to improve the accuracy and applicability of TASOPT in conceptual design of …
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Predicting fan noise propagation in aeroengine bypass ducts
… of rearwards fan noise propagation within the bypass duct and its radiation into the far feld. Two recently developed models: B-induct and GXMunt, are exploited in application to real engine bypass ducts and their performance is evaluated. These methods are an improvement on current industry …
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A method for identifying structural load share opportunities in aircraft powerplant configurations
… transport aircraft will be powered by next generation high bypass ratio engines which will have larger fan diameters producing higher levels of thrust. Consequentially structural and thermal demands will increase on individual power plant components. Under current design practice the various …
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An engine air-brake integration study
… uses variable exit guide vanes downstream of a high bypass ratio (BPR) fan rotor to produce drag quietly by swirling flow out of the fan nozzle. The swirling motion yields low pressure in the vortex core from simple radial equilibrium, thereby generating pressure drag. The 4-BB internal plug and …
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Numerical Studies of Jet-Wing Distributed Propulsion and a Simplified Noise Metric Method
… efficiency by changing the normal configuration of engine and aircraft. This concept is the jet-wing distributed propulsion idea, which redistributes the thrust across the span of the wings. Distributed propulsion is accomplished by using many smaller engines spread across the wings or …
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Influence of system architecture changes on organizational work flow and application to Geared turbofan engines
… turbine engine for aircraft applications is a highly integrated process, and requires the integration of efforts of large numbers of individuals from many design specialties. If the design process is well defined and the product architecture is stable, the outcome of the process will become …