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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Urban environmental health applications of remote sensing

An urban area was studied through the use of the inventory-by-surrogate method rather than by direct interpretation of photographic imagery. Prior uses of remote sensing in urban and public research are examined. The effects of crowding, poor housing conditions, air pollution, and street conditions on public health are considered. Color infrared photography was used to categorize land use features and the grid method was used in photo interpretation analysis. The incidence of shigella and salmonella, hepatitis, meningitis, tuberculosis, myocardial infarction and veneral disease were studied, together with mortality and morbidity rates. Sample census data were randomly collected and validated. The hypothesis that land use and residential quality are associated with and act as an influence upon health and physical well-being was studied and confirmed.

Rush, M.↗
NASA NTRS2009

Utilizing Remote Sensing Data to Ascertain Soil Moisture Applications and Air Quality Conditions

Recognizing the significance of NASA remote sensing Earth science data in monitoring and better understanding our planet's natural environment, NASA Earth Applied Sciences has implemented the 'Decision Support Through Earth Science Research Results' program. Several applications support systems through collaborations with benefiting organizations have been implemented. The Goddard Earth Sciences Data and Information Services Center (GES DISC) has participated in this program on two projects (one complete, one ongoing), and has had opportune ad hoc collaborations utilizing NASA Earth science data. GES DISC's understanding of Earth science missions and resulting data and information enables the GES DISC to identify challenges that come with bringing science data to research applications. In this presentation we describe applications research projects utilizing NASA Earth science data and a variety of resulting GES DISC applications support system project experiences. In addition, defining metrics that really evaluate success will be exemplified.

Leptoukh, Gregory↗
NASA NTRS1976

Fixed flat plate collector with a reversible vee-trough concentrator

An asymmetrical-reversible vee-trough concentrator for use both with nonevacuated and evacuated receivers is proposed in order to improve the performance of a fixed flat plate collector. The device is capable of maintaining a year-round concentration factor of about 2 while eliminating the complications of the tilt adjustments of the collector box assembly. Efficiency improvements and cost reductions for temperatures of about 100 and 200 C are offered for the nonvacuum and vacuum tube versions, respectively. A major advantage of the vee-trough is the enhancement of the incident flux, thus extending the collection period. The vacuum collector is suitable for supplying heat to solar Rankine systems, while the nonvacuum version can be used for air conditioning purposes via an absorption air conditioner.

Selcuk, M. K.↗
NASA NTRSDate not supplied

Deep Neural Network Based Unsteady Flamelet Progress Variable Approach in a Supersonic Combustor

Higher dimensional flamelet manifolds are essential in capturing the coupled effects of pressure gradients and unsteady chemical kinetics observed in supersonic combustion applications. Previous studies have validated the feasibility of using deep neural networks as an alternative to computation-ally intensive multidimensional flamelet table storage and lookup. This approach has demonstrated a significant reduction in memory footprint and enabled the use of larger dimensional tabulated manifolds for supersonic combustion in canonical problems. In this study, the Unsteady Flamelet Progress Variable (UFPV)-ANN model implemented in the VULCAN-CFD code is validated by the Burrows-Kurkov supersonic mixing/combustion configuration. The well characterized experimental problem consists of hydrogen injection into a supersonic vitiated crossflow that results in a lifted flame structure. The initial model consists of a 4-dimensional table where the independent variables Z, C, Xst, P are tabulated using an unsteady flamelet code with boundary conditions corresponding to the vitiated air conditions. The results show the development of a lifted flame structure and over-all acceptable agreement with finite-rate chemistry (FRC) simulation and the experimental data. Moreover, direct mapping between the independent variables and the flamelet table is replaced by a deep neural network for significant memory reduction. The results indicate that the UFPV-ANN approach can retrieve the same solution as the memory intensive lookup table approach.

Flamelet↗
NASA NTRS1982

Environmental Control Systems

Materials illustrating a presentation on environment control systems for electric flight systems are presented. Schematics and flow diagrams of fresh air source and air conditioning systems, and vapor cycle and air cycle parts lists are presented.

Rosenbush, F. M.↗
NASA NTRS1996

Fungal colonization of fiberglass insulation in the air distribution system of a multi-story office building: VOC production and possible relationship to a sick building syndrome

Complaints characteristic of those for sick building syndrome prompted mycological investigations of a modern multi-story office building on the Gulf coast in the Southeastern United States (Houston-Galveston area). The air handling units and fiberglass duct liner of the heating, ventilating and air conditioning system of the building, without a history of catastrophic or chronic water damage, demonstrated extensive colonization with Penicillium spp and Cladosporium herbarum. Although dense fungal growth was observed on surfaces within the heating-cooling system, most air samples yielded fewer than 200 CFU m-3. Several volatile compounds found in the building air were released also from colonized fiberglass. Removal of colonized insulation from the floor receiving the majority of complaints of mouldy air and continuous operation of the units supplying this floor resulted in a reduction in the number of complaints.

NASA Program Environmental Health↗
NASA NTRS1984

A numerical study of the controlled flow tunnel for a high lift model

A controlled flow tunnel employs active control of flow through the walls of the wind tunnel so that the model is in approximately free air conditions during the test. This improves the wind tunnel test environment, enhancing the validity of the experimentally obtained test data. This concept is applied to a three dimensional jet flapped wing with full span jet flap. It is shown that a special treatment is required for the high energy wake associated with this and other V/STOL models. An iterative numerical scheme is developed to describe the working of an actual controlled flow tunnel and comparisons are shown with other available results. It is shown that control need be exerted over only part of the tunnel walls to closely approximate free air flow conditions. It is concluded that such a tunnel is able to produce a nearly interference free test environment even with a high lift model in the tunnel.

Parikh, P. C.↗
NASA NTRS1985

Experimental study of the spray characteristics of a research airblast atomizer

Airblast atomization was studied using a especially designed atomizer in which the liquid first impinges on a splash plate, then is directed radially outward and is atomized by the air passing through two concentric, vaned swirlers that swirl the air in opposite directions. The effect of flow conditions, air mass velocity (mass flow rate per unit area) and liquid to air ratio on the mean drop size was studied. Seven different ethanol solutions were used to simulate changes in fuel physical properties. The range of atomizing air velocities was from 30 to 80 m/s. The mean drop diameter was measured at ambient temperature (295 K) and atmospheric pressure.

Acosta, W. A.↗
NASA NTRS1985

Three-dimensional viscous-shock-layer applications for the Space Shuttle orbiter

A nonorthogonal three-dimensional viscous-shock-layer code was modified and used to compute the windward surface flowfield over a Shuttle-like configuration. Code modifications were made in the methods used to evaluate shock boundary conditions and in the implementation of the equilibrium air models. Additional viscous terms were also retained in the governing equations. Effects of these modifications are demonstrated. Three-dimensional flowfield solutions obtained with the modified code showed good comparison of surface heating and pressure with actual flight data. An apparently three-dimensional effect, characterized by a drop in surface heating on the Shuttle windward centerline in the wing root area, was predicted by the present method. A preliminary review of Shuttle ground-based experimental and flight data confirmed this trend. The present three-dimensional solutions were also compared with the predictions of several approximate methods. Those comparisons showed the approximate methods to be valid for predicting heating along the Shuttle windward centerline uner both perfect gas and equilibrium air conditions.

Thompson, R. A.↗
NASA NTRS1985

Experimental study of the spray characteristics of a research airblast atomizer

Airblast atomization was studied using a especially designed atomizer in which the liquid first impinges on a splash plate, then is directed radically outward and is atomized by the air passing through two concentric, vaned swirlers that swirl the air in opposite directions. The effect of flow conditions, air mass velocity (mass flow rate per unit area) and liquid to air ratio on the mean drop size was studied. Seven different ethanol solutions were used to simulate changes in fuel physical properties. The range of atomizing air velocities was from 30 to 80 m/s. The mean drop diameter was measured at ambient temperature (295 K) and atmospheric pressure.

Acosta, W. A.↗
NASA NTRS2003

Thanksgiving Hocus Pocus

I was managing the construction project, and I thought my biggest challenge was simply finishing the work in time for start of the holiday shopping season. The store opened three weeks before Thanksgiving. Everything looked great. Business picked up steadily as the serious spending season approached. Then, two days before Thanksgiving, disaster struck. The fire protection system was designed to prevent smoke and fire from reaching the merchandise. If a fire alarm went off anywhere in the building, the system went into a massive pressurization mode. Dampers would open and the system would pump in hundreds of cubic feet of air from outside into the store, pressurizing every square foot, preventing fire or smoke from spreading into the store. That night an unknown event tripped the alarm-and it sounded for six hours. The air conditioning system was still operational as the outside air temperatures had been warm all month. That night, however, temperatures plummeted to 20 degrees. With an alarm sounding in a building complex that covers many millions of square feet, no one paid attention to the cold air flowing into the space. Pipes froze and burst. Hundreds of gallons of water came down through the drywall, soaking merchandise, the carpet and the hardwood racks. This state of the art system, which had been designed to protect, was now responsible for unthinkable damage. You could be the among greatest project managers in world, but if you have an attitude and you give the client heartburn, unnecessary heartburn, you're not going to do more work with him. If you have a disaster like this one, and you manage to make everybody feel good and believe that you are going to take care of them, then everybody looks back on it and says, "You know what, this is a good project team; we work well together, so let's do another one."

Zazzali, Christian↗
NASA NTRS2014

RETScreen Plus Software Tutorial

Greater emphasis is being placed on reducing both the carbon footprint and energy cost of buildings. A building's energy usage depends upon many factors one of the most important is the local weather and climate conditions to which it's electrical, heating and air conditioning systems must respond. Incorporating renewable energy systems, including solar systems, to supplement energy supplies and increase energy efficiency is important to saving costs and reducing emissions. Also retrofitting technologies to buildings requires knowledge of building performance in its current state, potential future climate state, projection of potential savings with capital investment, and then monitoring the performance once the improvements are made. RETScreen Plus is a performance analysis software module that supplies the needed functions of monitoring current building performance, targeting projected energy efficiency improvements and verifying improvements once completed. This tutorial defines the functions of RETScreen Plus as well as outlines the general procedure for monitoring and reporting building energy performance.

Ganoe, Rene D.↗
NASA NTRS1972

Sonic boom generation propagation and minimization.

Consideration of the possibility of reducing sonic boom noise to a level acceptable in populated areas. A detailed study is made of the possibility of predicting sonic boom generation, taking into account the effect of atmospheric conditions, air turbulence, and the effect of the shape and condition of the ground where people are located. The relation between the shape of the sonic boom signature on the ground and the aircraft shape is shown to be an important factor governing the use of supersonic aircraft over populated areas.

Ferri, A.↗