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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 145 records · Page 8

Experimental evaluation of two premixing-prevaporizing fuel injection concepts for a gas turbine catalytic combustor

A premixing-prevaporizing fuel system for a gas turbine catalytic combustor has been developed and evaluated. Spatial fuel distribution and degree of vaporization were measured at inlet temperatures up to 800 K and fuel-air ratios of 0.01 and 0.025. The test pressure was 0.5 MPa; velocity was 20 m/sec. Both a multiple-jet cross-stream injector and a splash-groove injector with a 30 deg air swirler exhibited a uniform fuel distribution and a high degree of vaporization with little total pressure drop. Fuel oxidation reactions were observed at the 800 K inlet air temperature, indicating that a different design concept is necessary for application with an automotive gas turbine.

Tacina, R.↗

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing Part I: System Analysis, Component Identification, Additive Manufacturing, and Testing of Polymer Composites

The research and development activities reported in this publication were carried out under NASA Aeronautics Research Institute (NARI) funded project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing." The objective of the project was to conduct evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. The results of the activities are described in three part report. The first part of the report contains the data and analysis of engine system trade studies, which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. The technical scope of activities included an assessment of the feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composites, which were accomplished by fabricating prototype engine components and testing them in simulated engine operating conditions. The manufacturing process parameters were developed and optimized for polymer and ceramic composites (described in detail in the second and third part of the report). A number of prototype components (inlet guide vane (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included turbine nozzle components. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

acoustic liners↗

Storage peak gas-turbine power unit

A storage gas-turbine power plant using a two-cylinder compressor with intermediate cooling is studied. On the basis of measured characteristics of a .25 Mw compressor computer calculations of the parameters of the loading process of a constant capacity storage unit (05.3 million cu m) were carried out. The required compressor power as a function of time with and without final cooling was computed. Parameters of maximum loading and discharging of the storage unit were calculated, and it was found that for the complete loading of a fully unloaded storage unit, a capacity of 1 to 1.5 million cubic meters is required, depending on the final cooling.

Tsinkotski, B.↗

Curved centerline air intake for a gas turbine engine

An inlet for a gas turbine engine was disposed about a curved centerline for the purpose of accepting intake air that is flowing at an angle to engine centerline and progressively turning that intake airflow along a curved path into alignment with the engine. This curved inlet is intended for use in under the wing locations and similar regions where airflow direction is altered by aerodynamic characteristics of the airplane. By curving the inlet, aerodynamic loss and acoustic generation and emission are decreased.

Ruehr, W. C.↗

Convertible Gas-Turbine Engines

Convertible engine aircraft gas-turbine is two engines in one. Produces turbofan thrust, turboshaft power, or any combined thrust and shaftpower continously while operating up to full speed. Used to power vertical/short-takeoff-and-landing (V/STOL) airplanes and advanced high-speed rotorcraft. Rotorcraft shows use of convertible engines rather than separate engines for rotor power and forward thrust affords advantages in installation and save 16 percent in fuel and 20 percent in direct operating costs. Engine used for propulsion of new high-speed rotorcraft that needs both thrust and shaft power. Also used to cross-couple fans of two-engine V/STOL aircraft.

Abdalla, K. L.↗

Preliminary Investigation of a Ceramic Lining for a Combustion Chamber for Gas-turbine Use

Combustion chamber liners for gas turbines and experimental set-ups were tested for failure. A ceramic-lined test chamber was operated at fuel/air ratios up to 0.050. Thermal-shock evaluation indicated that a ceramic lining, which expands after firing, would crack but would not fall apart during operation. Refractoriness of the lining and the resistance to mechanical shock were adequate. In general, shell temperature reductions of approximately 400 deg F were effected by the use of this lining at fuel/air ratios of 0.016 and 0.050. The mechanism of failure of the ceramic lining was induced by sudden heating and cooling during operation.

Woodward, William H↗

Turbulence models for gas turbine combustors

This viewgraph presentation covers gas turbine combustor flow physics, turbulence model investigations, turbulent combustion modeling, and present status and future needs.

Brankovic, Andreja↗

Gas Turbine Engine Inlet Wall Design

A gas turbine engine has an inlet duct formed to have a shape with a first ellipse in one half and a second ellipse in a second half. The second half has an upstream most end which is smaller than the first ellipse. The inlet duct has a surface defining the second ellipse which curves away from the first ellipse, such that the second ellipse is larger at an intermediate location. The second ellipse is even larger at a downstream end of the inlet duct leading into a fan.

Florea, Razvan Virgil↗

The 3-D CFD modeling of gas turbine combustor-integral bleed flow interaction

An advanced 3-D Computational Fluid Dynamics (CFD) model was developed to analyze the flow interaction between a gas turbine combustor and an integral bleed plenum. In this model, the elliptic governing equations of continuity, momentum and the k-e turbulence model were solved on a boundary-fitted, curvilinear, orthogonal grid system. The model was first validated against test data from public literature and then applied to a gas turbine combustor with integral bleed. The model predictions agreed well with data from combustor rig testing. The model predictions also indicated strong flow interaction between the combustor and the integral bleed. Integral bleed flow distribution was found to have a great effect on the pressure distribution around the gas turbine combustor.

Chen, D. Y.↗

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

Progress in the development of a gas turbine engine to improve fuel economy, reduce gaseous emissions and particulate levels, and compatible with a variety of alternate fuels is reported. The powertrain is designated AGT101 and consists of a regenerated single shaft gas turbine engine, a split differential gearbox and a Ford Automatic Overdrive production transmission. The powertrain is controlled by an electronic digital microprocessor and associated actuators, instrumentation, and sensors. Standard automotive accessories are driven by engine power provided by an accessory pad on the gearbox. Component/subsystem development progress is reported in the following areas: compressor, turbine, combustion system, regenerator, gearbox/transmission, structures, ceramic components, foil gas bearing, bearings and seals, rotor dynamics, and controls and accessories.

Source record↗

Gas turbine engine emissions - Problems, progress and future

The current status of the problem of gas turbine engine emissions is reviewed. Presently promulgated EPA standards and their implications for aircraft gas turbines are discussed. The progress and status of emissions reduction technology programs and other efforts which have emphasized advanced combustor technology are reviewed in detail. Also examined are those efforts underway to determine the emissions floor and incorporate those techniques into practical combustors of the future.

Jones, R. E.↗

Extension to an analysis of turbulent swirling compressible flow for application to axisymmetric small gas turbine ducts

An existing computer program, the Axisymmetric Diffuser Duct Code (ADD code), which calculates compressible turbulent swirling flow through axisymmetric ducts was modified to permit calculation of flows through small gas turbine ducts with struts, guide vanes and large degrees of turning. The improvements include a coordinate generator, an end-wall loss model, and a generalized geometry capability to describe struts and guide vanes in ducts which turn more than 90 degrees. An improved output format was developed to provide the solution on any arbitrary plane in the duct and an extensive literature survey of calculation procedures used in gas turbine technology was completed which suggests improvements in the computer code. Calculations are presented for the flow through the AGT101 small gas turbine inlet duct and turbine exhaust diffuser which demonstrate the ADD code modifications implemented in the investigation. The computed results compare favorably with experimental results.

Anderson, O. L.↗

Analytical Studies of Prompt NO(x) Emissions from Aircraft Gas Turbine Combustors

The reduction of oxides of nitrogen (NO(x)) emissions from aircraft gas turbines is a vital part of the NASA High Speed Research Program (HSRP). Emissions reduction studies are critical to the feasibility of future civil aircraft operating at supersonic speeds in the stratosphere. It is believed that large fleets of supersonic aircraft using conventional gas turbine engines would emit levels of NO(x) that are harmful to the stratospheric ozone layer.

Adelman, Henry G.↗

Geometry and Simulation Results for a Gas Turbine Representative of the Energy Efficient Engine (EEE)

This paper describes the geometry and simulation results of a gas-turbine engine based on the original EEE engine developed in the 1980s. While the EEE engine was never in production, the technology developed during the program underpins many of the current generation of gas turbine engines. This geometry is being explored as a potential multi-stage turbomachinery test case that may be used to develop technology for virtual full-engine simulation. Simulation results were used to test the validity of each component geometry representation. Results are compared to a zero-dimensional engine model developed from experimental data. The geometry is captured in a series of Initial Graphical Exchange Specification (IGES) files and is available in a supplement to this report.

Gas turbine engines↗

Geometry and Simulation Results for a Gas Turbine Representative of the Energy Efficient Engine (EEE)

This paper describes the geometry and simulation results of a gas-turbine engine based on the original EEE engine developed in the 1980s. While the EEE engine was never in production, the technology developed during the program underpins many of the current generation of gas turbine engines. This geometry is being explored as a potential multi-stage turbomachinery test case that may be used to develop technology for virtual full-engine simulation. Simulation results were used to test the validity of each component geometry representation. Results are compared to a zero-dimensional engine model developed from experimental data. The geometry is captured in a series of Initial Graphical Exchange Specification (IGES) files and is available in a supplement to this report.

Gas turbine engines↗

The effect of ambient temperature and humidity on the carbon monoxide emissions of an idling gas turbine

Changes in ambient temperature and humidity affect the exhaust emissions of a gas turbine engine. The results of a test program employing a JT8D combustor are presented which quantize the effect of these changes on carbon monoxide emissions at simulated idle operating conditions. Analytical results generated by a kinetic model of the combustion process and reflecting changing ambient conditions are given. It is shown that for a complete range of possible ambient variations, significant changes do occur in the amount of carbon monoxide emitted by a gas turbine engine.

Kauffman, C. W.↗