SEARCH · Engineering Papers
Results for “Engine”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Co-Optimization of Fuels & Engines: Efficiency Merit Function for Spark-Ignition Engines; Revisions and Improvements Based on FY16-17 Research
Early in fiscal year 2016 (FY16), a fuel efficiency 'merit function' was developed to provide a simple tool to evaluate the potential thermal efficiency benefits of various fuels when multiple fuel properties or performance metrics are changing simultaneously. It has also proven to be useful for evaluating various fuel candidates and provides a useful framework for capturing and summarizing results from multiple projects within the Co-Optima Fuel Properties and Advanced Engine Development research portfolios. The objective of this report is to collect pertinent research results from FY16 and the first half of FY17, and to integrate them into an improved merit function.
Acoustic prediction methods for rocket engines, including the effects of clustered engines and deflected exhaust flow
Acoustic prediction methods for rocket engines
Performance of the Components of the XJ34-WE-32 Turbojet Engine over a Range of Engine and Flight Conditions
Performance of the compressor, combustor, and turbine operating as integral parts of the XJ34-WE-32 turbojet engine was determined in the Lewis altitude wind tunnel over a range of altitudes from 5000 to 55,000 feet and flight Mach numbers from 0.28 to 1.05. Data were obtained for each of four exhaust-nozzle areas and are presented in graphical and tabular form.
The Effect of Engine Wear on Performance in the NSTAR 8000 Hour Ion Engine Endurance Test
One of the objectives of an ongoing wear test of the NSTAR ion thruster is to gain an understanding of how engine wear or aging affects performance.
Engineering Analysis Subsystem Environment for Spacecraft Engineering Subsystem Mission Operations
The Engineering Analysis Subsystem Environment (EASE) prototype is a collection of computer programs on networked workstations providing a multimission, multisubsystem environment that enables the operation of several spacecraft simultaneously with fewer analysts. Through the use of automated tools, graphical data visualization and information management, EASE has achieved an increase in mission operations productivity. Recently, a database, a trending tool, and a power sequence expansion tool have been added to EASE. This paper discusses these enhancements and provides an update of the operation experience with the realtime Galileo telemetry data.
Effect of heat and power extraction on turbojet-engine performance II : effect of compressor-outlet air bleed for specific modes of engine operation
Explore the source record for details and available documents.
Single-cylinder Engine Tests of Porous Chrome-plated Cylinder Barrels with Special Bore Coatings for Radial Air-cooled Engines
Explore the source record for details and available documents.
The performance of a composite engine consisting of a reciprocating spark-ignition engine, a blow-down turbine, and a steady-flow turbine
Explore the source record for details and available documents.
Analysis of Performance of a Jet Engine from Characteristics of Components II : Interaction of Components as Determined from Engine Operation
Explore the source record for details and available documents.
Heat-transfer processes in liquid-cooled engine cylinders I : correlation of single-cylinder engine temperatures under forced-convection cooling conditions
Explore the source record for details and available documents.
Analysis of cooling limitations and effect of engine-cooling improvements on level-flight cruising performance of a four-engine heavy bomber
Explore the source record for details and available documents.
Engineering Graphene-Ceramic 3D Composite Foams by Freeze Drying
A 3D graphene foam produced by the chemical vapor deposition (CVD) technique is recognized as an effective nanofiller material, as it does not agglomerate in the matrix. Though CVD facilitates pristine graphene foam production, the method poses limitations in developing large-scale 3D graphene composite foams as advanced engineering materials. In this paper, a freeze-drying (FD) process is used to produce a composite 3D foam, which is a mixture of graphene nanoplatelet (GNP) and a low-temperature co-fired ceramic (LTCC). The freeze-dried GNP-LTCC reticulated 3D composite foam has an average pore size ranging from 70 to 100 μm. Pore size is varied by regulating the heat transfer rate during the freezing process using a thermally conductive aluminum (Al) mold and a thermally insulating acrylonitrile butadiene styrene (ABS) mold. Computational thermal modeling is used to visualize the heat transfer and its effect on foam pore size. Subsequently, a freeze-dried GNP-LTCC composite foam is embedded into the LTCC matrix to form a hierarchical assembly by a spark plasma technique without compromising the 3D structure of the FD foam. This study established that a simple, eco-friendly, and scalable processing methodology can produce advanced graphene-based 3D composite foams as the future tailorable nanofillers for designing multimatrix materials.
Melt-Centrifuged (Bi,Sb) 2 Te 3 : Engineering Microstructure toward High Thermoelectric Efficiency
Microstructure engineering is an effective strategy to reduce lattice thermal conductivity (JG) and enhance the thermoelectric figure of merit (zT). Through a new process based on melt-centrifugation to squeeze out excess eutectic liquid, microstructure modulation is realized to manipulate the formation of dislocations and clean grain boundaries, resulting in a porous network with a platelet structure. In this way, phonon transport is strongly disrupted by a combination of porosity, pore surfaces/junctions, grain boundaries, and lattice dislocations. These collectively result in a ≈60% reduction of JG compared to zone melted ingot, while the charge carriers remain relatively mobile across the liquid-fused grains. This porous material displays a zT value of 1.2, which is higher than fully dense conventional zone melted ingots and hot pressed (Bi,Sb) 2 Te 3 alloys. A segmented leg of melt-centrifuged Bi 0.5 Sb 1.5 Te 3 and Bi 0.3 Sb 1.7 Te 3 could produce a high device ZT exceeding 1.0 over the whole temperature range of 323-523 K and an efficiency up to 9%. Here, we demonstrate a method for synthesizing high-efficiency porous thermoelectric materials through an unconventional melt-centrifugation technique.
Stabilization of Colloidal Crystals Engineered with DNA
Explore the source record for details and available documents.
Engineering Atomically Dispersed FeN[subscript 4] Active Sites for CO[subscript 2] Electroreduction
Explore the source record for details and available documents.