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Technical Paper

10 KWe Dual-Mode Space Nuclear Power System for Military and Scientific Applications

1992-08-03
929072
A 10 KWe dual-mode space power system concept has been identified which is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. The direct thrust capability can provide tens of pounds of thrust at a specific impulse of around 730 seconds for maneuvers that must be performed more rapidly. The direct thrust allows the nuclear power system to move a payload from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) in less than one month using approximately half the propellant of a cryogenic chemical stage.
Technical Paper

19-Color H2O Absorption Spectrometer Applied for Real-Time In-Cylinder Gas Thermometry in an HCCI Engine

2007-04-16
2007-01-0188
1 An all fiber-optic sensor has been developed to measure H2O mole fraction and gas temperature in an HCCI engine. This absorption-spectroscopy-based sensor utilizes a broad wavelength (1320 to 1380 nm) source (supercontinua generated by a microchip laser) and a series of fiber Bragg gratings (19 gratings centered on unique water absorption peaks) to track the formation and temperature of combustion water vapor. The spectral coverage of the system promises improved measurement accuracy over two-line diode-laser based systems. Meanwhile, the simplicity of the fiber Bragg grating chromatic dispersion approach significantly reduces the data reduction time and cost relative to previous supercontinuum-based sensors. The data provided by the system is expected to enhance studies of the chemical kinetics which govern HCCI ignition as well as HCCI modeling efforts.
Technical Paper

1970s Development of 21st Century Mobile Dispersed Power

1973-02-01
730709
A mobile and dispersed power system is necessary for an advanced technological-industrial society. Today's petroleum-based system discharges waste products and heat and is growing exponentially. Energy resource commitment has already intersected “ultimate” low-cost petroleum supplies in the United States and will do so for the world before 2000; this portends major changes and cost increases. The twenty-first century system for mobile-dispersed power will reflect the energy source selected to replace petroleum-for example, coal, solar insolation, or uranium. It will incorporate a fuel intermediate such as methanol, ammonia, or hydrogen, and a suitably matched “engine.” The complete change will require more than 25 years because of the magnitude, fragmentation, structural gaps, complexity, and variety of the mobile-dispersed power system.
Journal Article

1D Thermo-Fluid Dynamic Modeling of Reacting Flows inside Three-Way Catalytic Converters

2009-04-20
2009-01-1510
In this work a detailed model to simulate the transient behavior of catalytic converters is presented. The model is able to predict the unsteady and reacting flows in the exhaust ducts, by solving the system of conservation equations of mass, momentum, energy and transport of reacting chemical species. The en-gine and the intake system have not been included in the simulation, imposing the measured values of mass flow, gas temperature and chemical composition as a boundary condition at the inlet of the exhaust system. A detailed analysis of the diffusion stage triggering is proposed along with simplifications of the physics, finalized to the reduction of the calculation time. Submodels for water condensation and its following evaporation on the monolith surface have been taken into account as well as oxygen storage promoted by ceria oxides.
Technical Paper

21st Century Aircraft Potable Water Systems

1999-10-19
1999-01-5556
Aircraft potable (drinking) water systems haven’t changed significantly in the last half-century. These systems consist of cylindrical water tanks pressurized by bleed air from the jet engines, with insulated stainless steel distribution lines. What has changed recently is the increase in the possibility of aircraft picking up contaminated drinking water at foreign and domestic stops. Customer awareness of these problems has also changed - to the point where having reliable drinking water is now a competitive issue among airlines. Old style potable water systems that are used on modern aircraft are high maintenance and exacerbate the growth of microbes because the water is static much of the time. The integrity of some pressurized water tanks are also a concern after years of use. Cost-effective mechanical and biological solutions exist that can significantly reduce the amount of chemicals added and provide good potable water.
Technical Paper

41 Study of the Impact to the water Quality by Marine Engine Exhaust Emissions

2002-10-29
2002-32-1810
Starting with the laboratory study, the amount of exhaust emission compound dissolved in water was measured, and the divergence of exhaust emission compounds was reviewed. Measurements were taken for hydrocarbon (HC), especially benzene, toluene, m-Xylene, p-Xylene, and o-Xylene. It was verified that the amount of exhaust emission compounds dissolved in water has positive correlation with the volume of exhaust gas introduced into the water. The dissolved amount was smaller with the low emission engine model. Volatile Organic Compound (VOC) decreased sharply at the beginning, but the decrement got smaller after a certain period of time. Next research was performed on the actual river where PWC are being used. We looked into the possible correlation between the VOC's concentration in water and the distance to the water where a lot of PWC's are running. In addition the MTBE (Methyl Tertiary-Butyl Ether) concentration was measured.
Technical Paper

51 Examination on Measured Equivalent Sound Pressure Level and Sensory Evaluation for PWC Operating Sound

2002-10-29
2002-32-1820
When evaluating the sound generated by PWC (personal water craft), it is essential to study the measurement method for the PWC sound itself. However, it is equally important to identify the influence on the people in the neighbor of shoreline by being exposed to the sound from a group of PWC running around on waters. Such influence can be grasped in relation to the results of sensory evaluation. LAeq (equivalent continuous A-weighted sound level) was measured on PWC's running in various patterns and different numbers, while sensory evaluation was performed to obtain the data for the feelings the exposed persons would have about the sound. In this way the correlation between the sound pressure level and its perception by the people were analyzed. LAeq is the mixture of natural sound at the test site and the sound from the PWC(s) running in the predetermined patterns.
Standard

70 MPa Compressed Hydrogen Surface Vehicle Fuelling Connection Device and Optional Vehicle to Station Communications

2007-05-24
HISTORICAL
J2799_200705
This technical information report specifies a guideline for the hardware requirements for fueling a Hydrogen Surface Vehicle (HSV) with compressed hydrogen storage at a Nominal Working Pressure of 70MPa. It contains a description of the receptacle geometry and optional communication hardware and communications protocol to refuel the HSV. The intent of this document is to enable harmonized development and implementation of the hydrogen fueling interfaces. It is intended to be utilized for the hydrogen vehicle field evaluation until enough information is collected to enable standardardization. The receptable portion of this TIR is to be reevaluated utilizing international field data in approximately 2 years and subsequently superseded by J2600 in the 2009 timeframe.
Technical Paper

90 Ah Dependent Pressure Vessel (DPV) Nickel Hydrogen Battery Qualification Test Results

1999-08-02
1999-01-2590
In 1995, the Naval Research Laboratory (NRL) began a program to investigate whether a 90 Ah dependent pressure vessel (DPV) NiH2 battery pack could be a lower volume replacement for a 90 Ah NiH2 IPV spacecraft battery. Nickel Hydrogen (NiH2) dependent pressure vessel (DPV) battery cells are presumed to offer all the features of the NiH2 IPV battery cell with considerably less volume. To achieve this reduction in volume, the DPV cell utilizes a canteen shaped pressure vessel with reduced thickness wall, flat sides and curved ends. The cells can be packaged similar to prismatic nickel cadmium battery cells. Moreover, like NiCd cells, a fully charged DPV cell must rely upon an adjacent battery cell or structure for support and to maintain pressure vessel integrity. Seventeen 90 Ah NiH2 DPV cells were delivered to NR in 1998 for qualification tests. An eleven-cell half battery pack was manufactured and tested to validate the advantages of the DPV design.
Technical Paper

A 3D-Simulation with Detailed Chemical Kinetics of Combustion and Quenching in an HCCI Engine

2008-06-23
2008-01-1655
A 3D-CFD model with detailed chemical kinetics was developed to investigate the combustion characteristics of HCCI engines, especially those fueled with hydrogen and n-heptane. The effects of changes in some of the key important variables that included compression ratio and chamber surface temperature on the combustion processes were investigated. Particular attention was given, while using a finer 3-D mesh, to the development of combustion within the chamber crevices between the piston top-land and cylinder wall. It is shown that changes in the combustion chamber wall surface temperature values influence greatly the autoignition timing and location of its first occurrence within the chamber. With high chamber wall temperatures, autoignition takes place first at regions near the cylinder wall while with low surface temperatures; autoignition takes place closer to the central region of the mixture charge.
Technical Paper

A BRIEF SURVEY of the PRINCIPLES of PRESSURE WATER COOLING

1943-01-01
430122
AS speeds and operational altitudes of modern aircraft continue to increase, it is becoming more and more important that the total drag of the airplane be reduced while the rate of heat dissipation per unit frontal area of radiator be kept as high as possible. The standard method of increasing the temperature difference between cooling medium and coolant has been to use ethylene glycol as a coolant, because its boiling point is much higher than that of water; however, in its pure state glycol has various disadvantages that are not present when a pressure water system is used. This is a sealed system for making use of the physical characteristics of the increase in boiling temperature with pressure. When the radiator receives more heat from the engine than it is dissipating, a small quantity of steam is generated inside the cylinder jackets. The resulting increase in pressure will cause the temperature to rise until a balance is restored between heat rejection and radiator dissipation.
Technical Paper

A Before Treatment Method for Reduction of Emissions in Diesel Engines

2000-10-16
2000-01-2791
Through an addition of a small amount of hydrogen to the main fuel, combustion process can be considerably enhanced in internal combustion engines producing significantly lower levels of exhaust emissions. This improvement in combustion can be mainly attributed to the faster and cleaner burning characteristics of hydrogen in comparison to conventional liquid and gaseous fuels. An oxygen-enrichment of a fuel-air mixture also improves thermal efficiency and reduces especially particulate, carbon monoxide and unburned hydrocarbon emissions in exhaust. This contribution describes the results of experimental investigation where a small amount of hydrogen and oxygen is produced by Hydrogen Generating System through the electrical dissociation of water and are added to the intake of a compression ignition engine operating on a commercial diesel fuel. It is shown that level of exhaust emissions including NOx can be moderately reduced using such a pre-treatment method in diesel engines.
Technical Paper

A CFV Type Mini-dilution Sampling System for Vehicle Exhaust Emissions Measurement

1999-03-01
1999-01-0151
The traditional method for sampling vehicle exhaust has been the constant volume sampler (CVS) technique as described in the Code of Federal Regulations (CFR). This method dilutes the entire exhaust output from the vehicle, meters the mixture, and takes a proportional sample for measurement. The Mini-diluter sampling method reverses this process by first metering a small sample and then diluting to a fixed dilution ratio. This approach offers new opportunities to improve the quality of the sample measurement. This is especially interesting considering the lower emissions levels from ULEVs. The usefulness of this idea will depend on the development of stable and repeatable devices to implement it. This paper describes the operation of and presents results from a Mini-dilution system that uses critical flow venturis to provide a stable and repeatable dilution.
Technical Paper

A COMPARISON OF GRID-CONNECTED HYBRID AND HYDROGEN FUEL-CELL ELECTRIC VEHICLES

2007-09-16
2007-24-0073
For fuelling road transportation in the future, particularly light-duty vehicles, there has been much speculation about the use of hydrogen and fuel cells to provide electrical power to an all-electric drive train. An alternative powertrain would use a simple battery to store electricity directly, using power from the electrical grid to charge the battery when the vehicle is not in use. The energy efficiency of these two different approaches has been compared, using a complete “energy conversion chain analysis”. The successful development and introduction into the marketplace of grid-connected hybrid vehicles could eliminate the need for road vehicles to use petroleum fuels, at least for the majority of miles traveled. If electricity were to be generated primarily from sustainable primary energy sources, then road transportation would also become sustainable, resulting in an “Electricity Economy”, rather than a “Hydrogen Economy.
Technical Paper

A Canopy Model for Plant Growth Within a Growth Chamber: Mass and Radiation Balance for the Above Ground Portion

1991-07-01
911494
As humans move into outer space, need for air, clean water and food require that green plants be grown within all planetary colonies. The complexities of ecosystems require a sophisticated understanding of the interactions between the atmosphere, all nutrients, and life forms. While many experiments must be done to find the relationships between mass flows and chemical/energy transformations, it seems necessary to develop generalized models to understand the limitations of plant growth. Therefore, it is critical to have a robust modelling capability to provide insight into potential problems as well as to direct efficient experimentation. Last year we reported on a simple leaf model which focused upon the mass transfer of gases, radiation/heat balances, and the production of photosynthetically produced carbohydrate. That model indicated some of the plant processes which had to be understood in order to obtain parameters specific for each species.
Technical Paper

A Case Study of Stormwater Runoff Containing Deicing / Anti-icing Fluids Treatment at DFW Airport

2003-06-16
2003-01-2123
Airline tenants at Dallas/Fort Worth International Airport (DFW Airport) use deicing/anti-icing chemicals, as may be needed, to maintain wintertime operations. DFW Airport has implemented best management practices for pollution prevention measures relating to deicing/anti-icing activities. However, as the planes leave the deicing pads, deicing/anti-icing fluids can drip from the planes onto the runways, taxiways, and ramp areas. As planes take off, the fluids can also shear off onto Airport property. During winter storm events, these deicing/anti-icing fluids are flushed off the runways, etc., with the stormwater. Stormwater containing deicing/anti-icing fluids can discharge through outfalls into Trigg Lake located in the southwestern part of the DFW Airport property.
Technical Paper

A Catalytic Combustion System Coupled with Adsorbents for Air Clean Up in Sealed Spacecraft Environment

2003-07-07
2003-01-2624
Catalytic combustion coupled with activated carbon and molecular sieve adsorbents is applicable to all areas of air and gas clean up ranging from high to low levels of pollutants and trace contaminants control in a spacecraft environment is of no exception. In this study we propose a combined activated charcoal and catalytic combustion system based on a 70 watt power input achieving 350°C, operating on a 6 hour per 24 hour day catalytic cycle with an actual flow of 10.6 l min-1 in a residual free volume of 60 m3.
Technical Paper

A Characterization of Exhaust Emissions from Lean Burn, Rotary, and Stratified Charge Engines

1977-02-01
770301
This paper reports the results of an exhaust emissions characterization from the non-catalyst control systems employed on the Mazda RX-4 rotary, the Honda CVCC, and the Chrysler electronic lean burn. Throughout the paper, exhaust emissions from these vehicles are compared to those from a Chrysler equipped with an oxidation catalyst and an air pump. The emissions characterized are carbon monoxide, hydrocarbons, nitrogen oxides, sulfur dioxide, sulfates, hydrogen sulfide, carbonyl sulfide, hydrogen cyanide, aldehydes, particulate matter, and detailed hydrocarbons. A brief description of the sampling and analysis procedures used is included within the discussion.
Technical Paper

A Coast Guard Role in Civil Submersible Safety

1969-02-01
690027
The Coast Guard has a primary duty to administer laws and promulgate and enforce regulations for the promotion of safety of life and property on the high seas and on waters subject to the jurisdiction of the United States. The rapid expansion of undersea activity indicates a need for government regulation without waiting for a disaster to provide the impetus. The expected Coast Guard relationship to civil submersible safety is discussed from the standpoint of legislation; preparation, promulgation and enformcement of regulations; duplication of efforts by other organizations; and avoidance of unnecessary interference with use of new developments and technical advancement.
Technical Paper

A Combustion Products Analyzer for Contingency Use During Thermodegradation Events on Spacecraft

1991-07-01
911479
As mission length and the number and complexity of payload experiments increase, so does the probability of thermodegradation contingencies (e.g. fire, chemical release and/or smoke from overheated components or burning materials), which could affect mission success. When a thermodegradation event occurs on board a spacecraft, potentially hazardous levels of toxic gases could be released into the internal atmosphere. Experiences on board the Space Shuttle have clearly demonstrated the possibility of small thermodegradation events occurring during even relatively short missions. This paper will describe the Combustion Products Analyzer (CPA), which is being developed under the direction of the Toxicology Laboratory at Johnson Space Center to provide necessary data on air quality in the Shuttle following a thermodegradation incident.
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