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No description available.

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ABSTRACT Developments in the field of microturbine technology and gas turbine driven aircraft has been progressing without much progress in light aircraft predominantly propelled by piston engines. Because of inhibitive maintenance and overhaul costs of such however, propulsion via a gas turbine engine has been proposed with the potential of eventually replacing current engine configurations. Subsequently, the objective was to conceptually design a replacement gas turbine engine in the 150 kW range. A selection of case studies was used to illustrate the changing technologies to illustrate the technological viability of micro-gas turbines for light aircraft. Advantages and disadvantages of both engine types were discussed and a concise description of gas turbine operations and its components was given. A brief overview of fundamentals as well as the transmission layout was also supplied. Three configurations were isolated, namely the single spool design, a twin spool design featuring a free power turbine and the effect of a fuel conserving recuperator. Calculations were performed using Microsoft Excel, which proved sufficient in effectively calculating complex formulae - even under the necessary iterative feed-back conditions the design process demanded. Eventually, variable-specific design criteria were derived regarding the three engine types. Because fuel consumption still proved inhibitive, the effect of recuperation was investigated which yielded a very competitive engine - should the possibility of recuperator technology exist on time. As a result, one particular recuperated, single spool gas turbine engine was successfully identified. Having met all the design criteria sufficiently, this preliminary prototype design was numerically described and put within context of principal, peripheral working components such as a compatible gearbox layout.

Thesis (DBA(DoctorateofBusinessAdministration))--University of South Australia, 2003.

No description available.

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Model fan blades designed to implement the wake management technique of trailing-edge blowing were tested in a linear cascade configuration. Measurements were made on two sets of blowing blades installed in the Virginia Tech low-speed linear cascade wind tunnel. The simple blowing blades were identical to the baseline GE Rotor B blades, aside from a slight difference in trailing-edge thickness, a set of internal flow passages, and a blowing slot just upstream of the trailing-edge on the suction side of the blade. The Kuethe vane blades were also slightly thicker at the trailing-edge, and had a set of nine evenly spaced vortex generators upstream of the blowing slot on the suction side. The cascade tunnel accommodates eight blades with adjustable tip-gap heights, although only the center four blades were replaced by blowing blades in this study. The tunnel has an inlet angle of 65.1â a, a stagger angle of 56.9â a and a flow turning angle of 11.8â a. The tip-gap was set to 0.004125c and the freestream velocity of 24.7m/s led to a Reynolds number based on the chord of 385,000. Blowing slot uniformity measurements made with a single hot-wire immediately behind the trailing-edge revealed that the blowing becomes more spanwise uniform as blowing rate is increased. The same occurs with the Kuethe vane blades, despite a spanwise serrated pattern that appears as a result of the upstream vortex generators. Cross-sections made perpendicular to the blade span gave preliminary evidence that the simple blowing wake deficit increases from the passive suction case at a blowing rate of 1.4% and becomes overblown by 2.6%. The Kuethe vane wake deficit does not increase at low blowing rates. Both sets of blowing blades indicated a slight angling of the wake towards the pressure side with blowing. Pitot-static full cross-sections of the simple blowing blades at x/ca = 0.839 and 1.877 verified the increase in wake depth and width at 1.4% as compared to the passive suction and non-blowing baseline cases, and the wake overblowing that occurs as blowing rate is increased to approximately 2.6%. The Kuethe vane blades only achieve partial wake cancellation at the maximum tested rate of 2.6% for these measurements. The results of the baseline study of Geiger (2005) are used for comparison with the mid-span velocity profiles made at four downstream locations. The velocity profiles clearly confirm the results of the normal-to-span and full cross-sections, while also revealing a decrease from the baseline of at least 25% in most of the maximum Reynolds normal stresses and turbulent kinetic energies at all rates between 1.4% and 2.7% for both sets of blowing blades. Spectral measurements of the simple blowing blades show clear reductions of the energy in the wake for all blowing rates over the majority of the range of normalized frequencies, while the Kuethe vane blades show reductions at all rates and all frequencies. By performing Fourier decompositions, the tone noise benefits over the non-blowing baseline blades are directly comparable in decibels. The optimum blowing rate for the simple blowing blades is clearly 2.5%, since this rate shows the most potential tone noise reduction. The Kuethe vane blades suggest decreases in tone noise over all of the tested blowing rates. / Master of Science

International Telemetering Conference Proceedings / October 26-29, 1987 / Town and Country Hotel, San Diego, California / In an Independent Research and Development (IR&D) effort, the Telemetry Systems Operation (TSO) of Computer Sciences Corporation (CSC) sought to determine the feasibility of using Artificial Intelligence (AI) techniques in a real-time processing environment. Specifically, the use of an expert system to assist in telemetry data acquisition processing was studied. A prototype expert system was implemented with the purpose of monitoring F15 Vertical Short Take Off and Landing (VSTOL) aircraft engine tests in order to predict engine stalls. This prototype expert system was implemented on a Symbolics 3670 symbolic processor using Inference Corporation's Artificial Reasoning Tool (ART) expert system compiler/generator. The Symbolics computer was connected to a Gould/SEL 32/6750 real-time processor using a Flavors, Inc. Bus Link for real-time data transfer.