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 20 of 116 for “"turbofan"”.
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Description of a turbofan engine product development process
… are necessary for the development of a turbofan engine and how they evolve through the product development cycle. This work utilizes a parameter-based design structure matrix (DSM) to define the interfaces and interdependencies present in a large commercial aircraft propulsion system. …
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Acoustic Tomography and Thrust Estimation on Turbofan Engines
… order to accurately estimate the thrust of two turbofan engines (1.0-1.5%). In the second, it is shown that acoustic tomography methods that only use the first ray paths to arrive cannot distinguish some relevant propulsion flow fields (i.e., different flow fields can have the same times of …
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Detection filters for fault-tolerant control of turbofan engines
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1981.
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Turbofan engine sizing and tradeoff analysis via signomial programming/
This thesis presents a full 1D core+fan flowpath turbofan optimization model, based on first principles, and meant to be used during aircraft conceptual design optimization. The model is formulated as a signomial program, which is a type of optimization problem that can be solved locally using …
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Adaptive model-based control applied to a turbofan aircraft engine
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1990.
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Influence of Turbofan Engine Design Parameters on Aircraft Environmental Impact
… carriers and propulsion systems architectures, turbofan engines power the majority of commercial aircraft. Therefore, aviation’s environmental impacts are significantly influenced by the design of these turbofan engines. Hence, we should drive the design of modern turbofan engines, informed with …
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Turbofan rotor/stator interaction noise reduction through trailing edge blowing
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1998.
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Effect of BLI-Type Inlet Distortion on Turbofan Engine Performance
… layer flow through a serpentine inlet into a turbofan engine adversely affects the performance of the engine. The available literature has only yielded studies of the effects of this specific type of inlet distortion on engine performance in the form of numerical simulations. This work seeks …
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Data-Driven Modeling of Tracked Order Vibration in Turbofan Engine
… the tracked order vibration amplitudes of turbofan engines, the interdependencies and cross-correlation structure between various thermo-mechanical variables and tracked order vibration are analyzed. The order amplitudes are further contextualized in terms of their operating regime, and …
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Fluid Dynamics of Inlet Swirl Distortions for Turbofan Engine Research
… in a low-speed wind tunnel and in a full-scale turbofan research engine. Stereoscopic particle image velocimetry (PIV) was used to collect three-component velocity fields at discrete planes downstream of the generation of the distortions with two main objectives in mind: identifying the physics …
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Acoustic optimisation and prediction of sound propagation in turbofan engine ducts
… of noise propagation and<br/>radiation in turbofan engine intakes and bypass ducts, and the optimisation of noise attenuation<br/>by using acoustic liners. A commercial FE/IE code ACTRAN/TM is used<br/>within two shell programs; B-induct for bypass ducts and ANPRORAD for intake …
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Prediction and control of sound propagation in turbofan engine bypass ducts
… liners in the bypass duct of modern turbofan aeroengines. The liners provide the most<br/>effective means with which to suppress the rear fan noise. It is therefore important to make<br/>the best possible use of the available lined area by optimising the liner configuration. A …
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Mathematical modelling of noise generation in turbofan aeroengines using Green’s functions
… calculate the Green’s function for pressure in a turbofan duct with swirling mean flow and secondly we investigate the effect of turbulence hitting an isolated aerofoil. The Green’s function allows engineers to calculate the noise from rotor-stator interaction in simple cases and can be used in …
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A study of thermographic phosphor thermometry in an operating turbofan engine
… turbine blade metal temperatures in an operating turbofan engine test rig. Thermographic phosphors, ceramics doped with a rare earth metal, were bonded to the turbine blades. These phosphors exhibit fluorescence when optically excited by a laser, and both the intensity and the rate of decay of the …
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Evaluating approaches to detecting ice accretion in and around turbofan jet engines.
The accumulation of ice crystals in the compressor stages of a jet engine causes power loss events during flight that could potentially become catastrophic. The electromagnetic properties of ice clouds make them nearly undetectable to radars and hence the need for a new sensing technique. A …
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Analytical investigation of active control of radiated inlet noise from turbofan engines
… for reducing radiated tonal inlet noise from turbofan engines. The analytical model consists of multiple control sources placed in the periphery of the engine inlet duct which inject anti-noise into the duct to destructively interfere with the sound field generated by the fan. The development …
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Numerical characterization of rotor broadband noise sources in a high bypass-ratio turbofan
Le rôle du bruit de rotor devient plus important avec des développements récents des turboréacteurs. Il peut se comparer avec le bruit de l'interaction rotor-stator à cause de l'augmentation du diamètre de rotor ainsi que de la vitesse en tête de la pale. Par contre, il n'y a pas beaucoup d'études …
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A STUDY ON THE PHYSICS OF ICE ACCRETION IN A TURBOFAN ENGINE ENVIRONMENT
Numerous turbofan engine loss of thrust control events have led to a theory that ice is accreting on initially warmer than freezing internal engine hardware and affecting normal operation. The phenomenon is termed ice crystal icing. Previous ice crystal icing research on a simple airfoil …
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Combined Steam Power Cycle and Turbofan Engine for Improvement in Aviation Climate Impacts
… concepts that stray from the traditional turbofan engine. In this thesis, I develop an engine cycle model combining the turbofan engine with a steam power cycle and use the model to explore the benefits of applying this concept to aircraft engines. In order to study the impact to engine …
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A Method to Control Turbofan Engine Starting by Varying Compressor Surge Valve Bleed
… of a study of the starting conditions of a turbofan engine. The research focused on ways to minimize turbine inlet temperature while maintaining an adequate compressor stall margin during engine start by varying the surge valve bleed. Varying the surge valve bleed was also shown to reduce …
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