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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 19 records

Janus Superiority of Membranes in Chemical Engineering and Beyond

Janus configurations, characterized by their inherent asymmetry, enable directional mass transfer in membrane materials that drive novel and energy-efficient chemical processes. This Janus superiority spans applications from nanoscale molecular and ionic transport to macro-scale separation systems with asymmetric spatial architectures. This review provides an analysis of the material foundations including design principles, structure regulation, and scalability challenges underlying Janus membranes. Here, we explore the physics that governs their unique behavior and examine their diverse applications across chemical engineering, including phase transfer, and molecular or ionic transport. Through a multiscale perspective, we provide a comprehensive understanding of the impact of Janus superiority in advancing chemical engineering technologies. Finally, we discuss the hurdles in translating theoretical advances into practical applications and propose promising avenues for future research to harness the full potential of Janus membranes and systems in addressing global challenges related to energy, sustainability, and beyond.

Yang, Hao‐Cheng [Zhejiang University, Hangzhou (Ch

Chemical engineering design of CO oxidation catalysts

How a chemical reaction engineer would approach the challenge of designing a CO oxidation catalyst for pulsed CO2 lasers is described. CO oxidation catalysts have a long history of application, of course, so it is instructive to first consider the special requirements of the laser application and then to compare them to the characteristics of existing processes which utilize CO oxidation catalysts. All CO2 laser applications require a CO oxidation catalyst with the following characteristics: (1) active at stoichiometric ratios of O2 and CO, (2) no inhibition by CO2 or other components of the laser environment, (3) releases no particulates during vibration or thermal cycling, and (4) long lifetime with a stable activity. In all applications, low consumption of power is desirable, a characteristic especially critical in aerospace applications and, thus, catalyst activity at low temperatures is highly desirable. High power lasers with high pulse repetition rates inherently require circulation of the gas mixture and this forced circulation is available for moving gas past the catalyst. Low repetition rate lasers, however, do not inherently require gas circulation, so a catalyst that did not require such circulation would be favorable from the standpoint of minimum power consumption. Lasers designed for atmospheric penetration of their infrared radiation utilize CO2 formed from rare isotopes of oxygen and this application has the additional constraint that normal abundance oxygen isotopes in the catalyst must not exchange with rare isotopes in the gas mixture.

Herz, Richard K.

Selected Chemical Engineering Applications in Nuclear-Waste Processing at the Savannah River Site

The Savannah River Site has been successfully processing and immobilizing nuclear waste since 1996. However, recent developments in both the scientific understanding of chemical principles and the engineering of immobilizing nuclear-waste systems demand a review of the state of the art. These recent advances have significance to other locations that immobilize nuclear waste. Here, the subject matter of this review may find special applicability to chemical engineers interested in hazardous chemical processes (such as processing toxic and radioactive nuclear waste) and to those in the nuclear industry curious about current research in nuclear-waste processing at a site that has eclipsed the quarter-century mark of large-scale (136 million L total) nuclear-waste processing.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W

Chemical engineering: Measurements for a competitive age

The NIST (National Institute of Standards and Technology) activities supporting chemical research, environmental research, combustion and fuel research, and related industries are described in this video. Highlights include private sector involvement in the research and associated and guest scientist programs, the calibration of customers' instruments, and the direct funding for the NIST research projects by outside industries.

Source record

The role of chemical engineering in space manufacturing

A survey of factors involved in space manufacturing is presented. It is shown that it will be more economical to obtain the necessary raw materials from the moon than from earth due to earth's greater gravity and atmosphere. Discussion covers what resources can be mined and recovered from the moon and what ranges of industrial feedstock can be provided from lunar materials, noting that metallurgy will be different in space due to the lack of key elements such as H, C, Na, Cl, etc. Also covered are chemical plant design, space environmental factors such as vacuum and zero gravity, recycling requirments, reagent and equipment mass, and unit operations such as materials handling and phase separation. It is concluded that a pilot plant in space could be an economic boon to mankind.

Waldron, R. D.

Space chemical engines technology

The topics presented are covered in viewgraph form. The programmatic objective is to provide the technology necessary to proceed in the late 1990's with development of moderate-thrust LOX/LH2 expander cycle engines for various space transportation applications.

Berkopec, Frank D.

Researches on Preliminary Chemical Reactions in Spark-Ignition Engines

Chemical reactions can demonstrably occur in a fuel-air mixture compressed in the working cylinder of an Otto-cycle (spark ignition) internal-combustion engine even before the charge is ignited by the flame proceeding from the sparking plug. These are the so-called "prelinminary reactions" ("pre-flame" combustion or oxidation), and an exact knowledge of their characteristic development is of great importance for a correct appreciation of the phenomena of engine-knock (detonation), and consequently for its avoidance. Such reactions can be studied either in a working engine cylinder or in a combustion bomb. The first method necessitates a complicated experimental technique, while the second has the disadvantage of enabling only a single reaction to be studied at one time. Consequently, a new series of experiments was inaugurated, conducted in a motored (externally-driven) experimental engine of mixture-compression type, without ignition, the resulting preliminary reactions being detectable and measurable thermometrically.

Muehlner, E.

Low-thrust chemical rocket engine study

An analytical study evaluating thrust chamber cooling engine cycles and preliminary engine design for low thrust chemical rocket engines for orbit transfer vehicles is described. Oxygen/hydrogen, oxygen/methane, and oxygen/RP-1 engines with thrust levels from 444.8 N to 13345 N, and chamber pressures from 13.8 N/sq cm to 689.5 N/sq cm were evaluated. The physical and thermodynamic properties of the propellant theoretical performance data, and transport properties are documented. The thrust chamber cooling limits for regenerative/radiation and film/radiation cooling are defined and parametric heat transfer data presented. A conceptual evaluation of a number of engine cycles was performed and a 2224.1 N oxygen/hydrogen engine cycle configuration and a 2224.1 N oxygen/methane configuration chosen for preliminary engine design. Updated parametric engine data, engine design drawings, and an assessment of technology required are presented.

Shoji, J. M.

Mission Capabilities of Ion Engines Using SNAP-8 Power Supplies

Mission performance capabilities of ion engines powered by the 30 kw and 60 kw SNAP-8 power supplies are compared for the following missions: a 24-hr equatorial satellite, a 100 n mi lunar satellite, a 500 n mi Mars satellite, a Mercury probe, and an out-of-the-ecliptic probe. The capabilities of arc- jet engines and chemical engines for the same missions are compared with those of the ion engines. The majority of the comparisons are for 8500-lb spacecraft which are boosted into a 300 n mi orbit by the Atlas-Centaur. Variations in initial orbit altitude, the use of actual launch dates rather than dates based on simplifying assumptions, and the combined use of chemical and electrical propulsion systems were also evaluated in terms of their effect on mission performance.

IONIC PROPULSION

CFD applications in chemical propulsion engines

The present research is aimed at developing analytical procedures for predicting the performance and stability characteristics of chemical propulsion engines. Specific emphasis is being placed on understanding the physical and chemical processes in the small engines that are used for applications such as spacecraft attitude control and drag make-up. The small thrust sizes of these engines lead to low nozzle Reynolds numbers with thick boundary layers which may even meet at the nozzle centerline. For this reason, the classical high Reynolds number procedures that are commonly used in the industry are inaccurate and of questionable utility for design. A complete analysis capability for the combined viscous and inviscid regions as well as for the subsonic, transonic, and supersonic portions of the flowfield is necessary to estimate performance levels and to enable tradeoff studies during design procedures.

Merkle, Charles L.

Pretest uncertainty analysis for chemical rocket engine tests

A parametric pretest uncertainty analysis has been performed for a chemical rocket engine test at a unique 1000:1 area ratio altitude test facility. Results from the parametric study provide the error limits required in order to maintain a maximum uncertainty of 1 percent on specific impulse. Equations used in the uncertainty analysis are presented.

Davidian, Kenneth J.