SEARCH · Search NASA

Results for “Water use efficiency”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15

All sources NASA NTRS DOE OSTI

NASA NTRS2009

Water Contaminant Mitigation in Ionic Liquid Propellant

Appropriate system and operational requirements are needed in order to ensure mission success without unnecessary cost. Purity requirements applied to thruster propellants may flow down to materials and operations as well as the propellant preparation itself. Colloid electrospray thrusters function by applying a large potential to a room temperature liquid propellant (such as an ionic liquid), inducing formation of a Taylor cone. Ions and droplets are ejected from the Taylor cone and accelerated through a strong electric field. Electrospray thrusters are highly efficient, precise, scaleable, and demonstrate low thrust noise. Ionic liquid propellants have excellent properties for use as electrospray propellants, but can be hampered by impurities, owing to their solvent capabilities. Of foremost concern is the water content, which can result from exposure to atmosphere. Even hydrophobic ionic liquids have been shown to absorb water from the air. In order to mitigate the risks of bubble formation in feed systems caused by water content of the ionic liquid propellant, physical properties of the ionic liquid EMI-Im are analyzed. The effects of surface tension, material wetting, physisorption, and geometric details of the flow manifold and electrospray emitters are explored. Results are compared to laboratory test data.

Conroy, David↗

NASA NTRS2007

NASA's Potential Contributions for Remediation of Retention Ponds Using Solar Ultraviolet Radiation and Photocatalysis

This Candidate Solution uses NASA Earth science research on atmospheric ozone and aerosols data (1) to help improve the prediction capabilities of water runoff models that are used to estimate runoff pollution from retention ponds, and (2) to understand the pollutant removal contribution and potential of photocatalytically coated materials that could be used in these ponds. Models (the EPA's SWMM and the USGS SLAMM) exist that estimate the release of pollutants into the environment from storm-water-related retention pond runoff. UV irradiance data acquired from the satellite mission Aura and from the OMI Surface UV algorithm will be incorporated into these models to enhance their capabilities, not only by increasing the general understanding of retention pond function (both the efficacy and efficiency) but additionally by adding photocatalytic materials to these retention ponds, augmenting their performance. State and local officials who run pollution protection programs could then develop and implement photocatalytic technologies for water pollution control in retention ponds and use them in conjunction with existing runoff models. More effective decisions about water pollution protection programs could be made, the persistence and toxicity of waste generated could be minimized, and subsequently our natural water resources would be improved. This Candidate Solution is in alignment with the Water Management and Public Health National Applications.

Underwood, Lauren W.↗

NASA NTRS2009

Oxygen Production from Lunar Regolith using Ionic Liquids

The objective of this work and future follow-on work is to develop a safe, efficient, and recyclable method for oxygen and/or metals extraction from lunar regolith, in support of establishing a manned lunar outpost. The approach is to solubilize the oxides that comprise lunar regolith in media consisting of ionic liquids (ILs) and/or their mixtures at temperatures at or below 300 C. Once in solution, electrolysis can either be performed in-situ to generate oxygen at the anode and hydrogen and/or metals (silicon, iron, aluminum, titanium, etc.) at the cathode. Alternatively, the water that is generated during the solubilization process can be distilled out and condensed into a separate IL and then electrolysized to produce hydrogen and oxygen. In the case of lunar regolith, this method could theoretically produce 44g oxygen per 100g of regolith. The oxygen can be used for human life support and/or as an oxidizer for rocket fuels, and the metals can be used as raw materials for construction and/or device fabrication. Moreover, the hydrogen produced can be used to re-generate the acidic medium, which can then be used to process additional regolith, thereby making the materials recyclable and limiting upmass requirements. An important advantage of IL acid systems is that they are much "greener" and safer than conventional materials used for regolith processing such as sulfuric or hydrochloric acids. They have very low vapor pressures, which means that they contain virtually no toxic and/or flammable volatile content, they are relatively non-corrosive, and they can exhibit good stability in harsh environments (extreme temperatures, hard vacuum, etc.). Furthermore, regolith processing can be achieved at lower temperatures than other processes such as molten oxide electrolysis or hydrogen reduction, thereby reducing initial power requirements. Six ILs have been synthesized and tested for their capability to dissolve lunar simulant, and for electrochemical and thermal stability. The results showed that ILs can be very efficient electrolytes; in particular IL/phosphoric-acid mixtures appear extremely promising for solubilizing lunar simulant. Results from preliminary experiments for distillation of water produced from the oxygen within the metal oxides of the simulant and the hydrogen from the acid indicates that over 75% of the oxygen from the simulant can be harvested as water at a temperature of 150 C. A method for collection of oxygen from electrolysis of the water derived from solubilizing simulant was developed by using a liquid nitrogen trap to liquefy and collect the oxygen. Although precise quantification of the liquid oxygen trapped is difficult to obtain, the amount of hydrogen and oxygen collected from electrolysis of water in this system was greater than 98%. This set-up also included a portable mass spectrometer for the identification of gases released from electrolysis cells. Regeneration of ILs through re-protonation was also demonstrated. Four sequential re-generations of an IL following solubilization of simulant showed no significant differences in amounts of simulant dissolved. Follow-on work for this project should include more studies of IL/phosphoric acid systems. Also, much more work is necessary for defining methods for electrolysis and purification of metals from regolith solubilized in ILs, and for developing a system to use the produced hydrogen to regenerate the spent IL. Finally, design and development of flight breadboard and prototype hardware is required.

Paley, Mark Steven↗

NASA NTRS2008

Irrigation Requirement Estimation using MODIS Vegetation Indices and Inverse Biophysical Modeling; A Case Study for Oran, Algeria

Human demand for food influences the water cycle through diversion and extraction of fresh water needed to support agriculture. Future population growth and economic development alone will substantially increase water demand and much of it for agricultural uses. For many semi-arid lands, socio-economic shifts are likely to exacerbate changes in climate as a driver of future water supply and demand. For these areas in particular, where the balance between water supply and demand is fragile, variations in regional climate can have potentially predictable effect on agricultural production. Satellite data and biophysically-based models provide a powerful method to quantify the interactions between local climate, plant growth and water resource requirements. In irrigated agricultural lands, satellite observations indicate high vegetation density while the precipitation amount indicates otherwise. This inconsistency between the observed precipitation and the observed canopy leaf density triggers the possibility that the observed high leaf density is due to an alternate source of water, irrigation. We explore an inverse process approach using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), climatological data, and the NASA's Simple Biosphere model, SiB2, to quantitatively assess water demand in a semi-arid agricultural land by constraining the carbon and water cycles modeled under both equilibrium (balance between vegetation and prevailing local climate) and nonequilibrium (water added through irrigation) conditions. We postulate that the degree to which irrigated lands vary from equilibrium conditions is related to the amount of irrigation water used. We added water using two distribution methods: The first method adds water on top of the canopy and is a proxy for the traditional spray irrigation. The second method allows water to be applied directly into the soil layer and serves as proxy for drip irrigation. Our approach indicates that over the study site, for the month of July, spray irrigation resulted in an irrigation amount of about 1.4 mm per occurrence with an average frequency of occurrence of 24.6 hours. The simulated total monthly irrigation for July was 34.85 mm. In contrast, the drip irrigation resulted in less frequent irrigation events with an average water requirement about 57% less than that simulated during the spray irrigation case. The efficiency of the drip irrigation method rests on its reduction of the canopy interception loss compared to the spray irrigation method. When compared to a country-wide average estimate of irrigation water use, our numbers are quite low. We would have to revise the reported country level estimates downward to 17% or less

Bounoua, L.↗

NASA NTRS2006

An Analytical Solution of Radiative Transfer in the Coupled Atmosphere-Ocean System with Rough Surface

Using the efficient discrete-ordinate method, we present an analytical solution for radiative transfer in the coupled atmosphere-ocean system with rough air-water interface. The theoretical formulations of the radiative transfer equation and solution are described. The effects of surface roughness on radiation field in the atmosphere and ocean are studied and compared with measurements. The results show that ocean surface roughness has significant effects on the upwelling radiation in the atmosphere and the downwelling radiation in the ocean. As wind speed increases, the angular domain of sunglint broadens, the surface albedo decreases, and the transmission to ocean increases. The downward radiance field in the upper ocean is highly anisotropic, but this anisotropy decreases rapidly as surface wind increases and as depth in ocean increases. The effects of surface roughness on radiation also depend greatly on both wavelength and angle of incidence (i.e., solar elevation); these effects are significantly smaller throughout the spectrum at high sun. The model-observation discrepancies may indicate that the Cox-Munk surface roughness model is not sufficient for high wind conditions.

Jin, Zhonghai↗

NASA NTRS1985

Small centrifugal pumps for low thrust rockets

This paper presents the results of a combined analytical and experimental investigation of low specific speed pumps for potential use as components of propellant feed systems for low thrust rocket engines. Shrouded impellers and open face impellers were tested in volute type and vaned diffuser type pumps. Full- and partial-emission diffusers and full- and partial-admission impellers were tested. Axial and radial loads, head and efficiency versus flow, and cavitation tests were conducted. Predicted performance of two pumps are compared when pumping water and liquid hydrogen. Detailed pressure loss and parasitic power values are presented for two pump configurations. Partial-emission diffusers were found to permit use of larger impeller and diffuser passages with a minimal performance penalty. Normal manufacturing tolerances were found to result in substantial power requirement variation with only a small pressure rise change. Impeller wear ring leakage was found to reduce pump pressure rise to an increasing degree as the pump flowrate was decreased.

Gulbrandsen, N. C.↗

NASA NTRS2016

Thermal Propulsion Capture System Heat Exchanger Design

One of the biggest challenges of manned spaceflight beyond low earth orbit and the moon is harmful radiation that astronauts would be exposed to on their long journey to Mars and further destinations. Using nuclear energy has the potential to be a more effective means of propulsion compared to traditional chemical engines (higher specific impulse). An upper stage nuclear engine would allow astronauts to reach their destination faster and more fuel efficiently. Testing these engines poses engineering challenges due to the need to totally capture the engine exhaust. The Thermal Propulsion Capture System is a concept for cost effectively and safely testing Nuclear Thermal Engines. Nominally, hydrogen exhausted from the engine is not radioactive, but is treated as such in case of fuel element failure. The Thermal Propulsion Capture System involves injecting liquid oxygen to convert the hydrogen exhaust into steam. The steam is then cooled and condensed into liquid water to allow for storage. The Thermal Propulsion Capture System concept for ground testing of a nuclear powered engine involves capturing the engine exhaust to be cooled and condensed before being stored. The hydrogen exhaust is injected with liquid oxygen and burned to form steam. That steam must be cooled to saturation temperatures before being condensed into liquid water. A crossflow heat exchanger using water as a working fluid will be designed to accomplish this goal. Design a cross flow heat exchanger for the Thermal Propulsion Capture System testing which: Eliminates the need for water injection cooling, Cools steam from 5800 F to saturation temperature, and Is efficient and minimizes water requirement.

Richard, Evan M.↗

NASA NTRS2009

NASA Tech Briefs, September 2009

opics covered include: Filtering Water by Use of Ultrasonically Vibrated Nanotubes; Computer Code for Nanostructure Simulation; Functionalizing CNTs for Making Epoxy/CNT Composites; Improvements in Production of Single-Walled Carbon Nanotubes; Progress Toward Sequestering Carbon Nanotubes in PmPV; Two-Stage Variable Sample-Rate Conversion System; Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas; Board Saver for Use with Developmental FPGAs; Circuit for Driving Piezoelectric Transducers; Digital Synchronizer without Metastability; Compact, Low-Overhead, MIL-STD-1553B Controller; Parallel-Processing CMOS Circuitry for M-QAM and 8PSK TCM; Differential InP HEMT MMIC Amplifiers Embedded in Waveguides; Improved Aerogel Vacuum Thermal Insulation; Fluoroester Co-Solvents for Low-Temperature Li+ Cells; Using Volcanic Ash to Remove Dissolved Uranium and Lead; High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell; Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays; Micro-Horn Arrays for Ultrasonic Impedance Matching; Improved Controller for a Three-Axis Piezoelectric Stage; Nano-Pervaporation Membrane with Heat Exchanger Generates Medical-Grade Water; Micro-Organ Devices; Nonlinear Thermal Compensators for WGM Resonators; Dynamic Self-Locking of an OEO Containing a VCSEL; Internal Water Vapor Photoacoustic Calibration; Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings; Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays; Improved Scanners for Microscopic Hyperspectral Imaging; Rate-Compatible LDPC Codes with Linear Minimum Distance; PrimeSupplier Cross-Program Impact Analysis and Supplier Stability Indicator Simulation Model; Integrated Planning for Telepresence With Time Delays; Minimizing Input-to-Output Latency in Virtual Environment; Battery Cell Voltage Sensing and Balancing Using Addressable Transformers; Gaussian and Lognormal Models of Hurricane Gust Factors; Simulation of Attitude and Trajectory Dynamics and Control of Multiple Spacecraft; Integrated Modeling of Spacecraft Touch-and-Go Sampling; Spacecraft Station-Keeping Trajectory and Mission Design Tools; Efficient Model-Based Diagnosis Engine; and DSN Simulator.

Source record↗

NASA NTRSDate not supplied

Simultaneous Ice Water Content Measurements at Multiple Locations on the NASA DC-8 Aircraft during the 2018 HIWC RADAR Flight Campaign

Ice water content measurements were made simultaneously at three locations on the NASA DC-8 in natural, glaciated conditions during the 2018 High Ice Water Content RADAR flight campaign. The purpose of these measurements was to further evaluate efficiency factors of hot-wire total water content probes in glaciated conditions and investigate the enhancement of ice crystal concentrations near fuselage surfaces due to flow field inertial effects, and ice crystals impacting the nose, breaking up, and flowing downstream. The total water content measurements were made using either Science Engineering Associates Ice Crystal Detectors or Robust Probes. Three common sensors were mounted on an underwing canister considered to be in near free-flow conditions, a standoff from a fuselage window, and the nose of the fuselage near the pitot probes. The Ice Crystal Detector total water content sensor and Robust Probe sensor collection and retention efficiencies were evaluated through comparisons with the underwing Ice Crystal Detector and Robust Probe measurements to the IKP2 isokinetic evaporator probe, which provided the reference ice water content measurement. Local ice water content at the nose position was evaluated by comparing ratios of the nose and underwing ice crystal detectors to the IKP2. Local ice water content at the window-standoff location was also evaluated by comparing total water content sensor measurements from the window ice crystal detector to the measurements made with the underwing and nose Ice Crystal Detectors The key findings were: 1) the Ice Crystal Detector total water content sensor ice water content efficiency factor was similar to previous estimates, but reduced with increased ice crystal median mass diameter; 2) the ice water content at the fuselage nose location near the DC-8 pitot probes was approximately 2.5 times the freestream values – although this estimate is affected by a higher probe efficiency factor due to smaller particles in the debris cloud from impacts upstream of the probe; and 3) the ice water content at the 17” standoff from the port window varied from about 50% to 3 times freestream values in a complicated manner. Similar measurement locations are not uncommon on cloud research aircraft, where ice particle measurements may be subject to similar uncertainties.

Aircraft Icing↗

NASA NTRSDate not supplied

Simultaneous Ice Water Content Measurements at Multiple Locations on the NASA DC-8 Aircraft during the 2018 HIWC RADAR Flight Campaign

o Aircraft Icing↗

NASA NTRS1984

Evaluation and development of new VAS remote sensing algorithms

An algorithm, developed to permit the simultaneous retrieval of temperature/moisture profiles and surface skin temperature by direct analytical solution of the radiative transfer equation, alleviates the problem associated with the interdependencies of water vapor retrieval on temperature retrieval and their dependencies on surface emissions. Simultaneous solution of all these quantities is achieved in one calculation using the available radiance observations. Since only a single matrix inversion is required for the specification of all parameters, the solution is computationally efficient. Ancillary observations of temperature and/or moisture from surface sensors on aircraft can be readily incorporated into the solution. Simulation tests of the method indicate improved performance over the previous iterative technique, particularly for the lower troposphere and for water vapor.

Smith, W. L.↗

NASA NTRS1975

Collection and concentration of solar energy using Fresnel type lenses

The efficiency of collecting solar energy using a Fresnel type lens was measured for two different collectors. A flow collector utilizes the temperature difference and heat capacity in water measurements to determine the amount of absorbed energy retained from sun rays passing through the Fresnel lens. A static collector is a hollow copper box filled with vegetable heating oil for absorption of focused solar radiation.

Wilson, R. F.↗

NASA NTRS1976

Flash evaporator systems test

A flash evaporator heat rejection system representative of that proposed for the space shuttle orbiter underwent extensive system testing at the NASA Johnson Space Center (JSC) to determine its operational suitability and to establish system performance/operational characteristics for use in the shuttle system. During the tests the evaporator system demonstrated its suitability to meet the shuttle requirements by: (1) efficient operation with 90 to 95% water evaporation efficiency, (2) control of outlet temperature to 40 + or - 2 F for partial heat load operation, (3) stability of control system for rapid changes in Freon inlet temperature, and (4) repeated dormant-to-active device operation without any startup procedures.

Dietz, J. B.↗

NASA NTRS2016

Characterization of AlMn TES Impedance, Noise, and Optical Efficiency in the First 150 mm Multichroic Array for Advanced ACTPol

The Advanced ACTPol (AdvACT) upgrade to the Atacama Cosmology Telescope features large arrays of multichroic pixels consisting of two orthogonal-polarization pairs of superconducting bolometers at two observing frequency bands. We present measurements of the detector properties and noise data in a subset of a fielded multichroic array of AlMn transition-edge sensor (TES) detectors. In this array, the distribution of critical temperature T(sub c) across detectors appears uniform at the percent level. The measured noise-equivalent power (NEP) distributions over approximately 1200 detectors are consistent with expectations. We find median NEPs of 4.0×10(exp −17) W/ √ Hz for low-band detectors and 6.2×10(exp −17) W/ √ Hz for high-band detectors under covered-window telescope test conditions with optical loading comparable to observing with precipitable water vapor approximately 0.5 mm. Lastly, we show the estimated detector optical efficiency, and demonstrate the ability to perform optical characterization over hundreds of detectors at once using a cryogenic blackbody source.

Crowley, Kevin T.↗

NASA NTRS2021

Simultaneous Ice Water Content Measurements at Multiple Locations on the NASA DC-8 Aircraft during the 2018 HIWC RADAR Flight Campaign

Ice water content measurements were made simultaneously at three locations on the NASA DC-8 in natural, glaciated conditions during the 2018 High Ice Water Content RADAR flight campaign. The purpose of these measurements was to further evaluate efficiency factors of hot-wire total water content probes in glaciated conditions and investigate the enhancement of ice crystal concentrations near fuselage surfaces due to flow field inertial effects, and ice crystals impacting the nose, breaking up, and flowing downstream. The total water content measurements were made using either Science Engineering Associates Ice Crystal Detectors or Robust Probes. Three common sensors were mounted on an underwing canister considered to be in near free-flow conditions, a standoff from a fuselage window, and the nose of the fuselage near the pitot probes. The Ice Crystal Detector concave total water content sensor and Robust Probe sensor collection and retention efficiencies were evaluated through comparisons with the underwing Ice Crystal Detector and Robust Probe measurements to the Isokinetic Probe version 2 (IKP2), which provided the reference ice water content measurement. Local ice water content at the nose position was evaluated by comparing ratios of the nose and underwing ice crystal detectors to the IKP2. Local ice water content at the window-standoff location was also evaluated by comparing total water content sensor measurements from the window probes to the measurements made with the underwing and nose probes. The key findings were: (1) the Ice Crystal Detector concave water content sensor efficiency factor to glaciated conditions was similar to previous estimates, but reduced with increased ice crystal median mass diameter; (2) the ice water content at the fuselage nose location near the DC-8 pitot probes was approximately 2.5 times the freestream values—although this estimate is affected by a higher probe efficiency factor due to smaller particles in the debris cloud from impacts upstream of the probe; and (3) the ice water content at the 17 in. standoff from the port window varied from about 50 percent to nearly three times freestream values in a complicated manner. Similar measurement locations are not uncommon on cloud research aircraft, where ice particle measurements may be subject to similar uncertainties.

Aircraft Icing↗

NASA NTRS2012

Why Isn't the Earth Completely Covered in Water?

If protoplanets formed from 10 to 20 kilometer diameter planetesimals in a runaway accretion process prior to their oligarchic growth into the terrestrial planets, it is only logical to ask where these planetesimals may have formed in order to assess the initial composition of the Earth. We have used Weidenschilling's model for the formation of comets (1997) to calculate an efficiency factor for the formation of planetesimals from the solar nebula, then used this factor to calculate the feeding zones that contribute to material contained within 10, 15 and 20 kilometer diameter planetesimals at 1 A.U. as a function of nebular mass. We find that for all reasonable nebular masses, these planetesimals contain a minimum of 3% water as ice by mass. The fraction of ice increases as the planetesimals increase in size and as the nebular mass decreases, since both factors increase the feeding zones from which solids in the final planetesimals are drawn. Is there really a problem with the current accretion scenario that makes the Earth too dry, or is it possible that the nascent Earth lost significant quantities of water in the final stages of accretion?

Nuth, Joseph A., III↗

NASA NTRS2012

Preliminary Feasibility Testing of the BRIC Brine Water Recovery Concept

The Brine Residual In-Containment (BRIC) concept is being developed as a new technology to recover water from spacecraft wastewater brines. Such capability is considered critical to closing the water loop and achieving a sustained human presence in space. The intention of the BRIC concept is to increase the robustness and efficiency of the dewatering process by performing drying inside the container used for the final disposal of the residual brine solid. Recent efforts in the development of BRIC have focused on preliminary feasibility testing using a laboratory- assembled pre-prototype unit. Observations of the drying behavior of actual brine solutions processed under BRIC-like conditions has been of particular interest. To date, experiments conducted with three types of analogue spacecraft wastewater brines have confirmed the basic premise behind the proposed application of in-place drying. Specifically, the dried residual mass from these solutions have tended to exhibit characteristics of adhesion and flow that are expected to continue to challenge process stream management designs typically used in spacecraft systems. Yet, these same characteristics may favor the development of capillary- and surface-tension-based approaches currently envisioned as part of an ultimate microgravity-compatible BRIC design. In addition, preliminary feasibility testing of the BRIC pre-prototype confirmed that high rates of water recovery, up to 98% of the available brine water, may be possible while still removing the majority of the brine contaminants from the influent brine stream. These and other early observations from testing are reported.

Callahan, Michael R.↗

NASA NTRS2011

Preliminary Feasibility Testing of the BRIC Brine Water Recovery Concept

The Brine Residual In-Containment (BRIC) concept was developed as a new technology to recover water from spacecraft wastewater brines. Such capability is considered critical to closing the water loop and achieving a sustained human presence in space. The intention of the BRIC concept is to increase the robustness and efficiency of the dewatering process by performing drying inside the container used for the final disposal of the residual brine solid. Recent efforts in the development of BRIC have focused on preliminary feasibility testing using a laboratory- assembled pre-prototype unit. Observations of the drying behavior of actual brine solutions processed under BRIC-like conditions has been of particular interest. To date, experiments conducted with three types of analogue spacecraft wastewater brines have confirmed the basic premise behind the proposed application of in-place drying for these solutions. Specifically, the dried residual mass from these solutions have tended to exhibit characteristics of adhesion and flow that are expected to continue to challenge process stream management in spacecraft brine dewatering system designs. Yet, these same characteristics may favor the development of capillary- and surface-tension-based approaches envisioned as part of an ultimate microgravity-compatible BRIC design. In addition, preliminary feasibility testing of the BRIC pre-prototype confirmed that high rates of water recovery, up to 98% of the available brine water, may be possible while still removing the majority of the brine contaminants from the influent brine stream. These and other observations from testing are reported.

Callahan, Michael R.↗