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 21 for “"Turbochargers"”.
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Turbochargers to small turbojet engines for uninhabited aerial vehicles
Three test programs were conducted to provide thepreliminary groundwork for thedesign of a small turbojet engine from turbocharger rotorcomponents for possible Uninhabited Aerial Vehicle applications. The first program involved the performance mapping of the Garrett T2 turbocharger centrifugal …
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An experimental investigation of centrifugal compressor surge and stall phenomena in turbochargers
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1984.
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A Study of Methods for Improving the Dynamic Stability of High-Speed Turbochargers
… development has emerged. Most diesel engine turbochargers incorporate floating-ring bearings that use the engine's oil for lubrication. The high-speed turbocharger is known to have subsynchronous vibrations at high amplitudes for a wide speed range that could reach 150,000 rpm. The bearing …
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Stability Analysis of a Turbocharger for Marine Diesel Engine Service
… critical in high-speed machinery such as turbochargers. Large turbochargers, such as those found in marine diesel propulsion engines where the rotor alone often exceeds forty pounds, require careful consideration regarding stability as well as load support during the bearing selection …
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Evaluation of Alternate Bearing Designs in a High Speed Automotive Turbocharger
Automotive turbochargers experience self-excited instabilities through the majority of their operating speed range. The results of these instabilities can cause damage to the bearings, shafts, and housing walls. Preventing this damage while maintaining or increasing performance characteristics is a …
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Influence of Induced Unbalance on Subsynchronous Vibrations of an Automotive Turbocharger
… instability is present in most or all automotive turbochargers. High subsynchronous amplitudes can cause a variety of problems in areas such as mechanical failures, emissions regulations and rotor design. Self-excited vibrations from sources of damping can lock in at lateral natural frequencies …
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Synchronous Thermal Instability Evaluation of Medium Speed Turbocharger Rotor-Bearing Systems
… development of the Morton Effect in medium-speed turbochargers typical to shipboard propulsion engines and the effect that bearing clearance has on thermal stability. Floating ring and tilting pad journal bearings are considered with a single stage, overhung centrifugal compressor and an overhung …
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Locomotive emissions effects due to engine configuration
… second study was to determine if remanufactured turbochargers and used cylinder liners were able to meet current EPA standards. (Abstract shortened by UMI.).
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Dynamic Performance of Turbocharger Rotor-Bearing Systems
… and friction characteristics of two identical turbochargers differing only by the support structure of the rotor system; one containing a floating ring bearing turbocharger (FRBT) and the other a ball bearing turbocharger (BBT). A pair of displacement sensors was installed to measure the whirl …
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Radial-turbine mistuning
… of the common failure modes of the diesel engine turbochargers is high-cycle fatigue of the turbine-wheel blades. Mistuning of the blades due to the casting process is believed to contribute to this failure mode. A laser vibrometer is used to characterize mistuning for a population of turbine …
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Development of a MEMS turbocharger and gas turbine engine
… rotordynamic and fabrication constraints. The turbochargers consist of a back-to-back centrifugal compressor and radial inflow turbine supported on gas bearings with a design rotating speed of 1.2 Mrpm. This design speed is many times the natural frequency of the radial bearing system. …
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Aerothermodynamics and operation of turbine system under unsteady pulsating flow
… flow environment typically found in vehicular turbochargers is made to: identify the key operating parameters, enable the formulation of a reduced order model, delineate the sources of loss and suggest strategies for performance improvement. The turbine system consists of a scroll-volute …
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Study on mixing, modelling and control of an SCR system
… reactors before or after the turbines of engine turbochargers. This thesis focuses on modelling of evaporation and decomposition of urea-water-solution (UWS) droplets, design and optimisation of static mixers, modelling of an SCR reactor and developing model-based urea dosing control strategy.The …
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An Investigation into the impact of the spanwise flow field at rotor inlet on the performance of mixed flow turbines
… downsized engines are increasingly equipped with turbochargers to increase the power output. This has placed a greater emphasis on turbocharger performance across the full operating range. Therefore, turbocharger turbines must be capable of operating with high efficiency at off-design conditions, …
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Homopolar bearingless slice motors with magnet-free rotors for extracorporeal life support
… applications, such as steam turbines and turbochargers in vehicles.
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Flow Analysis of Vibration Modes in Turbocharger Turbines
The purpose of this research is to help understand the influence of time-dependent fluid dynamics forces on the fatigue failure of turbomachinery blades. To that end, we conduct computational flow analysis of a turbocharger turbine with 13 rotor blades and 14 stator blades for precomputed …
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An investigation to determine the complexity and feasibility of combustion & NOx modelling in modern GTDI engines
… the model exclusively again because the turbochargers pressure ratio dependence for mass air flow is extremely sensitive. As the model was developed it became clear that despite being able to show some correlation at lower engine speeds and controlling the model across all other aspects …
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Turbocharger Turbines: An Experimental Study on the Effects of Wastegate Size and Flow Passage Design
… investigates three different automotive turbochargers of varying turbine/wastegate combination: two of similar turbine housing (BorgWarner) but different bypass throat diameter (20 and 26 mm), and a third of both different housing (Honeywell) and throat size from the former two (21 mm). …
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Thermodynamic design optimisation of an open recuperative twin-shaft solar thermal Brayton cycle with combined or exclusive reheating and intercooling
… and a pair of proprietary automotive turbochargers configured to operate as micro-turbines. An additional modified cavity receiver and cross-flow plate heat exchanger constitute the reheater and intercooler, respectively. Net power output is expressed in terms of the temperature and …
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Modeling and control of wastegate equipped turbocharged engines
A method of modeling, simulating (transient), and designing controllers for turbocharged engine systems is presented. The method is specific to spark ignition (SI) engines equipped with pneumatic, spring diaphragm, wastegate actuators, with solenoid valve active boost control. The method revolves …
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