Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Operations and Maintenance”

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.

At least 1,459 records · Page 81
All sourcesNASA NTRSDOE OSTI
NASA NTRS2002

Powering the Future

Stirling Technology Company (STC) developed the RG-350 convertor using components from separate Goddard Space Center and U.S. Army Natick SBIR contracts. Based on the RG-350, STC commercialized a product line of Stirling cycle generator sets, known as RemoteGen(TM), with power levels ranging from 10We to 3kWe. Under SBIR agreements with Glenn Research Center, the company refined and extended the capabilities of the RemoteGen convertors. They can provide power in remote locations by efficiently producing electricity from multiple-fuel sources, such as propane, alcohol, gasoline, diesel, coal, solar energy, or wood pellets. Utilizing any fuel source that can create heat, RemoteGen enables the choice of the most appropriate fuel source available. The engines operate without friction, wear, or maintenance. These abilities pave the way for self-powered appliances, such as refrigerators and furnaces. Numerous applications for RemoteGen include quiet, pollution-free generators for RVs and yachts, power for cell phone towers remote from the grid, and off-grid residential power variously using propane, ethanol, and solid biomass fuels. One utility and the National Renewable Energy Laboratory are evaluating a solar dish concentrator version with excellent potential for powering remote irrigation pumps.

Source record↗
NASA NTRS1992

Technology for Water Treatment (National Water Management)

The buildup of scale and corrosion is the most costly maintenance problem in cooling tower operation. Jet Propulsion Laboratory successfully developed a non-chemical system that not only curbed scale and corrosion, but also offered advantages in water conservation, cost savings and the elimination of toxic chemical discharge. In the system, ozone is produced by an on-site generator and introduced to the cooling tower water. Organic impurities are oxidized, and the dissolved ozone removes bacteria and scale. National Water Management, a NASA licensee, has installed its ozone advantage systems at some 200 cooling towers. Customers have saved money and eliminated chemical storage and discharge.

Source record↗
NASA NTRS2005

Cost-Cutting Powdered Lubricant

Scientists at NASA's Glenn Research Center developed a high-temperature, solid lubricant coating material that is saving the manufacturing industry millions of dollars. The material came out of 3 decades of tribological research, work studying high-temperature friction, lubrication, and the wearing of interacting surfaces that are in relative motion. It was developed as a shaft coating deposited by thermal spraying to protect foil air bearings used in oil-free turbomachinery, like gas turbines, and is meant to be part of a larger project: an oil-free aircraft engine capable of operating at high temperatures with increased reliability, lowered weight, reduced maintenance requirements, and increased power. This advanced coating, PS300, is a self-lubricating bearing material containing chromium oxide, with additions of a low-temperature start up lubricant (silver) and a high-temperature lubricant, making it remarkably stable at high temperatures, and better suited than previously available materials for high-stress conditions. It improves efficiency, lowers friction, reduces emissions, and has been used by NASA in advanced aeropropulsion engines, refrigeration compressors, turbochargers, and hybrid electrical turbogenerators. PS300 is ideal in any application where lowered weight and reduced maintenance are desired, and high-temperature uses and heavy operating speeds are expected. It has notable uses for the Space Agency, but it has even further-reaching potential for the industrial realm.

Source record↗
NASA NTRS2006

Robots in Space -Psychological Aspects

A viewgraph presentation on the psychological aspects of developing robots to perform routine operations associated with monitoring, inspection, maintenance and repair in space is shown. The topics include: 1) Purpose; 2) Vision; 3) Current Robots in Space; 4) Ground Based Robots; 5) AERCam; 6) Rotating Bladder Robot (ROBLR); 7) DART; 8) Robonaut; 9) Full Immersion Telepresence Testbed; 10) ERA; and 11) Psychological Aspects

Sipes, Walter E.↗
NASA NTRS2007

Proposed Array-based Deep Space Network for NASA

The current assets of the Deep Space Network (DSN) of the National Aeronautics and Space Administration (NASA), especially the 70-m antennas, are aging and becoming less reliable. Furthermore, they are expensive to operate and difficult to upgrade for operation at Ka-band (321 GHz). Replacing them with comparable monolithic large antennas would be expensive. On the other hand, implementation of similar high-sensitivity assets can be achieved economically using an array-based architecture, where sensitivity is measured by G/T, the ratio of antenna gain to system temperature. An array-based architecture would also provide flexibility in operations and allow for easy addition of more G/T whenever required. Therefore, an array-based plan of the next-generation DSN for NASA has been proposed. The DSN array would provide more flexible downlink capability compared to the current DSN for robust telemetry, tracking and command services to the space missions of NASA and its international partners in a cost effective way. Instead of using the array as an element of the DSN and relying on the existing concept of operation, we explore a broader departure in establishing a more modern concept of operations to reduce the operations costs. This paper presents the array-based architecture for the next generation DSN. It includes system block diagram, operations philosophy, user's view of operations, operations management, and logistics like maintenance philosophy and anomaly analysis and reporting. To develop the various required technologies and understand the logistics of building the array-based lowcost system, a breadboard array of three antennas has been built. This paper briefly describes the breadboard array system and its performance.

telemetry↗
NASA NTRS2007

Wirelessly Interrogated Position or Displacement Sensors

Two simple position or displacement sensors based on inductance-capacitance resonant circuits have been conceived. These sensors are both powered and interrogated without use of wires and without making contact with other objects. Instead, excitation and interrogation are accomplished by means of a magnetic-field-response recorder. Both of the present position or displacement sensors consist essentially of variable rectangular parallel-plate capacitors electrically connected in series with fixed inductors. Simple inductance-capacitance circuits of the type used in these sensors are inherently robust; their basic mode of operation does not depend on maintenance of specific environmental conditions. Hence, these sensors can be used under such harsh conditions as cryogenic temperatures, high pressures, and radioactivity.

Woodard, Stanley E.↗
NASA NTRS2003

Pneumatically Actuated Miniature Peristaltic Vacuum Pumps

Pneumatically actuated miniature peristaltic vacuum pumps have been proposed for incorporation into advanced miniature versions of scientific instruments that depend on vacuum for proper operation. These pumps are expected to be capable of reaching vacuum-side pressures in the torr to millitorr range (from .133 down to .0.13 Pa). Vacuum pumps that operate in this range are often denoted roughing pumps. In comparison with previously available roughing pumps, these pumps are expected to be an order of magnitude less massive and less power-hungry. In addition, they would be extremely robust, and would operate with little or no maintenance and without need for oil or other lubricants. Portable mass spectrometers are typical examples of instruments that could incorporate the proposed pumps. In addition, the proposed pumps could be used as roughing pumps in general laboratory applications in which low pumping rates could be tolerated. The proposed pumps could be designed and fabricated in conventionally machined and micromachined versions. A typical micromachined version (see figure) would include a rigid glass, metal, or plastic substrate and two layers of silicone rubber. The bottom silicone layer would contain shallow pump channels covered by silicone arches that could be pushed down pneumatically to block the channels. The bottom silicone layer would be covered with a thin layer of material with very low gas permeability, and would be bonded to the substrate everywhere except in the channel areas. The top silicone layer would be attached to the bottom silicone layer and would contain pneumatic- actuation channels that would lie crosswise to the pump channels. This version is said to be micromachined because the two silicone layers containing the channels would be fabricated by casting silicone rubber on micromachined silicon molds. The pneumatic-actuation channels would be alternately connected to a compressed gas and (depending on pump design) either to atmospheric pressure or to a partial vacuum source. The design would be such that the higher pneumatic pressure would be sufficient to push the silicone arches down onto the substrates, blocking the channels. Thus, by connecting pneumatic- actuation channels to the two pneumatic sources in spatial and temporal alternation, waves of opening and closing, equivalent to peristalsis, could be made to move along the pump channels. A pump according to this concept could be manufactured inexpensively. Pneumatic sources (compressors and partial vacuum sources) similar those needed for actuation are commercially available; they typically have masses of .100 g and power demands of the order of several W. In a design-optimization effort, it should be possible to reduce masses and power demands below even these low levels and to integrate pneumatic sources along with the proposed pumps into miniature units with overall dimensions of no more than a few centimeters per side.

Feldman, Sabrina↗
NASA NTRS2013

Engineered Surfaces for Mitigation of Insect Residue Adhesion

Maintenance of laminar flow under operational flight conditions is being investigated under NASA s Environmentally Responsible Aviation (ERA) Program. Among the challenges with natural laminar flow is the accretion of residues from insect impacts incurred during takeoff or landing. Depending on air speed, temperature, and wing structure, the critical residue height for laminar flow disruption can be as low as 4 microns near the leading edge. In this study, engineered surfaces designed to minimize insect residue adhesion were examined. The coatings studied included chemical compositions containing functional groups typically associated with abhesive (non-stick) surfaces. To reduce surface contact by liquids and enhance abhesion, the engineered surfaces consisted of these coatings doped with particulate additives to generate random surface topography, as well as coatings applied to laser ablated surfaces having precision patterned topographies. Performance evaluation of these surfaces included contact angle goniometry of pristine coatings and profilometry of surfaces after insect impacts were incurred in laboratory scale tests, wind tunnel tests and flight tests. The results illustrate the complexity of designing antifouling surfaces for effective insect contamination mitigation under dynamic conditions and suggest that superhydrophobic surfaces may not be the most effective solution for preventing insect contamination on aircraft wing leading edges.

Siochi, Emilie J.↗
NASA NTRS2014

What to Expect When Your Workplace is in Deep Space

Working life on a vehicle going to Mars would have some things in common with going to work on Earth, but most would have that twist to remind you that you're not on Earth anymore. Regardless of where we are or what we're working on humans need to eat, sleep, stay healthy and stay active and alert to perform well on the job. Studies on Earth have shown how important each element is to an individual's wellbeing and job performance. To travel in space we create a vehicle that provides the basic needs required by humans, these include carrying supplies of air, water and food. However we also need the protective shell to carry the humans, all their supplies and the systems to ensure that people can breathe, stay warm, address all bodily functions and stay healthy in space. In addition to just surviving the new environments, work tasks such as equipment maintenance and repair, normal crew operations and special science experiments will be performed. Some of the factors that will affect the crew performance include: environmental adaptation to weightlessness, dealing with cramped living quarters, physical changes caused by space travel, and how the tools, equipment, training and support information are used throughout the voyage. Different conditions can affect how the crew performs their work; we need to know more about living and working under these conditions to have successful human exploration in space.

DeMott, Diana↗
NASA NTRS2014

What to Expect When Your Workplace is in Deep Space

Working life on a vehicle going to Mars would have some things in common with going to work on Earth, but most would have that twist to remind you that you're not on Earth anymore. Regardless of where we are or what we're working on humans need to eat, sleep, stay healthy and stay active and alert to perform well on the job. Studies on Earth have shown how important each element is to an individual's wellbeing and job performance. To travel in space we create a vehicle that provides the basic needs required by humans, these include carrying supplies of air, water and food. However we also need the protective shell to carry the humans, all their supplies and the systems to ensure that people can breathe, stay warm, address all bodily functions and stay healthy in space. In addition to just surviving the new environments, work tasks such as equipment maintenance and repair, normal crew operations and special science experiments will be performed. Some of the factors that will affect the crew performance include: environmental adaptation to weightlessness, dealing with cramped living quarters, physical changes caused by space travel, and how the tools, equipment, training and support information are used throughout the voyage. Different conditions can affect how the crew performs their work; we need to know more about living and working under these conditions to have successful human exploration in space.

DeMott, Diana↗
NASA NTRS2015

Characterization of a Regenerable Impactor Filter for Spacecraft Cabin Applications

Regenerable filters will play an important role in human exploration beyond low-Earth orbit. Life Support Systems aboard crewed spacecrafts will have to operate reliably and with little maintenance over periods of more than a year, even multiple years. Air filters are a key component of spacecraft life support systems, but they often require frequent routine maintenance. Bacterial filters aboard the International Space Station require almost weekly cleaning of the pre-filter screen to remove large lint debris captured in the microgravity environment. The source of the airborne matter which is collected on the filter screen is typically from clothing fibers, biological matter (hair, skin, nails, etc.) and material wear. Clearly a need for low maintenance filters requiring little to no crew intervention will be vital to the success of the mission. An impactor filter is being developed and tested to address this need. This filter captures large particle matter through inertial separation and impaction methods on collection surfaces, which can be automatically cleaned after they become heavily loaded. The impactor filter can serve as a pre-filter to augment the life of higher efficiency filters that capture fine and ultrafine particles. A prototype of the filter is being tested at the Particulate Filtration Laboratory at NASA Glenn Research Center to determine performance characteristics, including particle cut size and overall efficiency. Model results are presented for the flow characteristics near the orifice plate through which the particle-laden flow is accelerated as well as around the collection bands.

air filters↗
NASA NTRS2015

Turbo-Brayton Power Converter

Future NASA space missions will require advanced thermal-to-electric power converters that are reliable, efficient, and lightweight. Creare, LLC, is developing a turbo-Brayton power converter that offers high efficiency and specific power. The converter employs gas bearings to provide maintenance free, long-life operation. Discrete components can be packaged to fit optimally with other subsystems, and the converter's continuous gas flow can communicate directly with remote heat sources and heat rejection surfaces without the need for ancillary heat-transfer components and intermediate flow loops. Creare has completed detailed analyses, trade studies, fabrication trials, and preliminary designs for the components and converter assembly. The company is fabricating and testing a breadboard converter.

Breedlove, Jeffrey↗
NASA NTRS2015

Future of Condition Based Maintenance at Stennis

This study seeks to understand the current state of condition based maintenance (CBM) at Stennis Space Center and set a bench mark for the future expansion of the CBM program. Condition based maintenance is the idea of maintaining an asset upon decreasing performance or when a failure is impending instead of at some arbitrary time regardless of condition. Special attention was paid to remote sensing and monitoring of assets around the center to cut maintenance costs and extend overall operational lifetime of those assets. It was found that 55 percent of the categories of assets which could actually utilize a remote CBM program are currently being partially monitored. CBM solutions that have been investigated and proposed for future deployment cover areas such as building integrity, oil analysis, power line and water pipe inspection.

George, Cory A.↗
NASA NTRS1985

Space Telescope Systems Description Handbook

The objective of the Space Telescope Project is to orbit a high quality optical 2.4-meter telescope system by the Space Shuttle for use by the astronomical community in conjunction with NASA. The scientific objectives of the Space Telescope are to determine the constitution, physical characteristics, and dynamics of celestial bodies; the nature of processes which occur in the extreme physical conditions existing in stellar objects; the history and evolution of the universe; and whether the laws of nature are universal in the space-time continuum. Like ground-based telescopes, the Space Telescope was designed as a general-purpose instrument, capable of utilizing a wide variety of scientific instruments at its focal plane. This multi-purpose characteristic will allow the Space Telescope to be effectively used as a national facility, capable of supporting the astronomical needs for an international user community and hence making contributions to man's needs. By using the Space Shuttle to provide scientific instrument upgrading and subsystems maintenance, the useful and effective operational lifetime of the Space Telescope will be extended to a decade or more.

Carter, R. E.↗
NASA NTRS2018

Dynamic Adjustment of Simulation Parameters for Efficient Vehicle Prognostics

Model-based diagnostics and prognostics rely on state estimation and uncertainty management algorithms to produce useful information for system operators and maintainers. This information enables more informed operational decisions, condition-based maintenance, and overall mission safety assurance. Typically, uncertainty is associated with vehicle state-of-health estimation and prediction results because of modeling errors, internal or external sources of noise, and sensor inaccuracy. Probabilistic uncertainty management methods including Sequential Monte Carlo simulation are commonly used to reason about state-of-health estimates and predictions in the presence of these sources of uncertainty. However, such algorithms can be computationally expensive as they require a very large number of samples to obtain a sufficiently accurate quantification of the end of life probability distribution. As a result, highly mobile autonomous systems that leverage the prognostic results for mission-level replanning are often constrained in their processing capability because of these computationally expensive simulation approaches. Therefore, in this paper, we investigate algorithmic methods for dynamically adjusting simulation time step as well as number of samples to achieve highly efficient prognostic results while maintaining results accuracy. Results obtained from simulated flight experiments of an electric unmanned aerial vehicle are presented to verify the efficacy of such algorithms.

Prognostics↗
NASA NTRS2014

Controllable Multi-Functional Heat Exchanger for Space Applications

Team Spacering will design SpaceRing, a cooling and waste heat recycling system that addresses NASA’s interest for a cooling and power-generating unit in its prototype deep space habitat[1]. The merits of this system are as follows: - Controllable cooling is critical in maintaining a habitable environment and in the functionality of life support systems, powering electronics and other devices in a spacecraft. - Power is expensive to produce in a space environment. Converting wasted thermal energy into electricity will save energy and money for the space station. Space habitation is a highly complex endeavor. Consequently, the SpaceRing must adhere to additional constraints, which include: - Lack of natural fluid or gas convection due to micro-gravity environment - Limited range for heat source and cold sink temperature - Subject to high fluctuations of incoming thermal energy - Minimal weight due to the high cost of transporting items into space After consulting with NASA and experts in thermal studies, several design objectives were identified and are listed below in order of importance: - High cooling capacity - Reliable safety control and alert system - Maximization of energy generation from wasted heat - Optimization of cooling capability and power generation - Long operational life and minimization of maintenance In space, conventional cooling systems utilize passive heat pipe systems for small-scale heat rejection and pumped pipes with heat exchangers for large-scale heat rejection. Thermal power generation in space is mainly achieved by using thermoelectric material that produces electric energy from temperature differentials. We propose a design that combines cooling and thermoelectric power generation. Using a hot pipe connected to a heat source, a cold pipe connected to a radiator, a heat exchanger in contact with both pipes, and a pump in each pipe to move the fluid, we make an active cooling system. The thermoelectric material is inserted in the heat exchanger between the hot and cold pipes to extract energy from the maximum temperature difference coming from the two pipes. It also provides controllable cooling capacity through the use of the thermoelectric material as cooling modules. We have tested our system under target heat source and sink conditions and measured the temperatures and flow rates. Our preliminary results are promising, demonstrating the output of 25 Watts of power on average. We are in the process of running control tests to compare the heat transfer performance without the thermoelectric generators, which is vital in determining whether or not the generators introduce an unacceptable amount of thermal resistance. While some control tests have been run already, the results have been noisy. We have modified our testing environment and data acquisition methods to allow for simple comparison between the control test results and thermoelectric performance results. Lastly, we have modified the heat exchanger design slightly to include acrylic baffles. This will allow the heat to flow through the heat exchanger more efficiently. We have presented our preliminary results to NASA and will deliver the final product by the end of May 2014.

Lee Xiong↗
DOE OSTI2020

Integration of Data Analytics with Plant System Health Program

This report summarizes the R&D activities of the Plant Health Management (PHM) project during fiscal year 2020 (FY20). This project focuses on the development of methods that integrate component health data and propagate such information at the system level to evaluate system sources of risk. This project development lives in cooperation with the Risk Informed Asset Management (RIAM) project. The RIAM project, in fact, uses the reliability models and data generated by the PHM project to optimize plant operations (e.g., maintenance/replacement schedule, optimal maintenance posture). This year’s activities for the PHM project focused mainly on the development of two classes of models. The first one includes a series of component reliability models which include aging, testing and maintenance. The second class includes a series of system reliability models which focus on the secondary side of exiting U.S. reactors. These models are based on fault tree logic structures such that they can be used by existing plant PRA software. We also started to focus on the management of health data and we tackled this issue in two directions. The first one focuses on the integration of monitor data with simulation models to assess component health. This approach is moving from a classical data based to a model+data based approach with the goal of improving higher component health information. The second direction focuses on linking equipment reliability data (e.g., maintenance/failure reports, component monitoring data) directly to system reliability models using a safety margin based language rather than a probability based language. The main advantage of a safety margin based language is that it can provide to system engineers more tangible information on system/component health and how it propagates to the system level.

97 MATHEMATICS AND COMPUTING↗
NASA NTRS1975

LST refurbishment and support

The Large Space Telescope (LST) is a Space Shuttle payload with relatively high reliability, but it will require maintenance support in order to meet the operational life requirement of 15 years. It was determined that it would be efficient and economical to support LST by having four limited inflight maintenance (IFM) missions and three ground refurbishments. The IFM missions would include replacement of the four items with a limited operating life. The LST program would provide for a ground refurbishment every four years at a central payload depot. It was recommended that the depot should be located at MSFC and be manned by a permanent party which would be augmented on a temporary basis during LST refurbishments by engineering personnel from the LST contractors. Required spare parts would be acquired incrementally for the depot based on maximum refurbishment of repairable items.

Henschke, J.↗