Browse Topic: Cold weather

Items (104)
Find
Weather Support to Deicing Decision Making (WSDDM) Winter Weather Nowcasting SystemAS5537A (Current)02/10/2021
The purpose of this SAE Aerospace Standard is to provide guidelines for the components and configurations that define the research and commercial versions of the Weather Support to Deicing Decision Making (WSDDM) winter weather nowcasting system.
G-12M Methods Committee
Technical Standard
Leaf-Inspired Surface Prevents Frost FormationTBMG-3685805/01/2020
Researchers have discovered a new way to significantly reduce frost formation on any surface. The finding could help decrease the amount of energy needed for defrosting and could potentially result in fewer canceled flights, which can be grounded by even the slightest layer of frost.
Magazine Article
Sensor Heat Relief20AVEP03_0703/01/2020
Canatu's carbon nanobots keep critical sensor surfaces -and LED headlamps - clean in sub-freezing weather. Sensor surfaces that are exposed to weather need to be kept clean so that ADAS and autonomous driving systems can function safely. Ice build-up in cold conditions is of particular concern, but Canatu thinks it has a solution. The Finland-based technology company has developed a transparent, highly conductive heater element that does not require metallic wires to be placed in front of the sensor. These elements keep lidar sensors and cameras ice-free, thanks to carbon nanobot (CNB) heaters.
Berman, Bradley
Magazine Article
Land Combat MissileTBMG-3486008/01/2019
MBDA Incorporated Arlington, VA 703-387-7139
Magazine Article
Automotive Engineering: June 201919AUTP0606/06/2019
Rethinking aluminum for NVH abatement Engineers, abandon those mastics! New "quiet" materials solutions are at hand. Paradigm shift in NVH A new wave of vehicle technologies is changing the way Brüel & Kjaer attacks noise, vibration and harshness. How a Tier 2 tackles NVH Saint-Gobain invested in anechoic testing so small components can make a big NVH difference. Reducing NVH through refined powertrain measurement The C1000 vastly simplifies measuring the mass matrix of heavy, odd shaped engines and powertrains. Foam for NVH solutions New innovations for a wide variety of sound-deadening applications. Long time coming: 2020 Corvette After six decades of teasing enthusiasts with intriguing concepts, Chevrolet is launching an all-new Corvette with its engine located where Zora intended-behind the driver. Protecting high-voltage circuits Yazaki readies a new solution for arc suppression in circuits of 48V or more. Editorial The unforgettable pyramid on the hood Supplier Eye Enter the
Magazine Issue
Battery Provides Electric Vehicles with Immunity from Climate ConditionsTBMG-3341412/01/2018
Conventional lithium-ion batteries cannot be rapidly charged at temperatures below 50 °F. Electric vehicles are popular on the West Coast because the weather is conducive to quick charging. Once the vehicles are moved to the East Coast or Canada, there is a tremendous issue with charging.
Magazine Article
Aerogel Insulation Makes Thinner, Warmer OuterwearTBMG-3320611/01/2018
Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
Magazine Article
Artificial “Blubber” Protects Divers in Frigid WaterTBMG-3248208/01/2018
When Navy SEALs carry out dives in Arctic waters, or when rescue teams are diving under ice-covered rivers or ponds, the survival time even in the best wetsuits is very limited — as little as tens of minutes. Researchers have discovered a process to triple that survival time.
Magazine Article
Flight Awareness Collaboration Tool (FACT)TBMG-2885605/01/2018
Winter weather such as snow, freezing precipitation, and ice can impact airport surface operations. These conditions may result in significant disruptions in arrival and departure rates. To address these issues, NASA Ames Research Center has developed a software application called the Flight Awareness Collaboration Tool (FACT). This tool is designed to reduce the number of unnecessary flight cancellations by improving situation awareness of an impending winter weather event and its effects on airports. FACT provides the necessary data for decision-making, and supports collaboration between the organizations involved in managing flight and airport operations. It gathers the information necessary for winter weather management into one location and has predictive tools. Being Web-based, it can be available to multiple users.
Magazine Article
A Progress Review on Gas Purge for Enhancing Cold Start Performance in PEM Fuel Cell2018-01-131204/03/2018
Cold start capability is one of remaining major challenges in realizing PEMFC (Proton Exchange Membrane Fuel Cell) technology for automotive applications. Gas purge is a common and integral shutdown procedure of a PEMFC automotive in subzero temperature. A dryer membrane electrode assembly (MEA) can store more water before it gets saturated and ice starts to penetrate in the open pores of porous media, thus enhancing cold start capability of a PEMFC. Therefore, gas purge is always performed prior to fuel cell shutdown to minimize residual water in a PEMFC. In the hope of improving effectiveness of purge in a PEMFC vehicle, two important purge parameters are evaluated including purge time and energy requirement. In practice, an optimized gas purge protocol should be developed with minimal parasitic energy, short purge duration and no degradation of components. To conclude, the cold start capability and performance can be consolidated by proper design of gas purge strategies. Despite of
Xu, Peng, Xu, Sichuan
Technical Paper
Zinc Alloy Ingot and Die Casting CompositionsJ468_201801 (Current)01/09/2018
SIMILAR SPECIFICATIONS—UNS Z33521, former SAE 903, ingot is similar to ASTM B 240-79, Alloy AG40A; and UNS Z33520, former SAE 903, die casting is similar to ASTM B 86-76, Alloy AG40A. UNS Z35530, former SAE 925, ingot is similar to ASTM B 240-79, Alloy AC41A; and UNS Z35531, former SAE 925, die casting is similar to ASTM B 86-82a, Alloy AC41A.
Metals Technical Committee
Technical Standard
Multi-Functional Yarns and Fabrics with Anti-Microbial, Anti-Static, and Anti-Odor CharacteristicsTBMG-2801212/01/2017
Prior art fabrics used to manufacture military combat uniforms typically are made from yarns comprised of a blend of cotton and nylon fibers. This blend supports dyeing and printing techniques that use a combination of acid and vat dyes to impart a camouflage pattern. The yarns made from the blend are combined with lightweight, thin fabric construction to produce fabrics that provide comfort, durability, and UV resistance. Other fabrics, such as flame-retardant fabrics, are made from blends of Nomex® synthetic fiber meta-aramid fiber, Kevlar® synthetic fiber para-aramid fiber, and P140 electrostatic-dissipative fiber, and also provide a level of visual and near-infrared camouflage protection; however, they do not provide anti-odor, anti-micro-bial, or electrostatic dissipation performance in a single, complete fabric. Other prior art techniques involve treating uniform fabrics with antimicrobial treatments, but some of these are not durable and wear out after repeated laundering.
Magazine Article
Effects of the Glass and Body Heat Transfer Characteristics of an Electric Vehicle on its Energy Consumption and Cruising Distance2016-01-026004/05/2016
In order to develop various parts and components of electric vehicles, understanding the effects of their structures and thermal performance on the energy consumption and cruising distance is important. However, such essential and detailed information is generally not always available to suppliers of vehicle parts and components. This paper presents the development of a simple model of the energy consumption by an electric vehicle in order to roughly calculate the cruising performance based only on the published information to give to suppliers, who otherwise cannot obtain the necessary information. The method can calculate the cruising distance within an error of 4% compared to the published information. The effects of the glass and body heat transfer characteristics on the cruising performance in winter were considered as an example application of the proposed model. An anti-fog control method was modeled, where the relative humidity around the front windshield was assumed to be
Ozeki, Yoshiichi, Nagano, Hideaki, Kohri, Itsuhei
Journal Article
Compilation of Freezing Brake Experience and Suggested Designs and Operating Procedures Required to Prevent Its OccurrenceAIR4762 (Historical)08/20/2014
This AIR describes conditions under which freezing brakes can occur and offers suggested design features to minimize occurrence. It also suggests operating procedures which have been shown to prevent or lessen the severity of brake freezing.
A-5A Wheels, Brakes and Skid Controls Committee
Information Report
Capacitive Humidity Sensors Using Highly Durable Polyimide MembraneTBMG-1936604/01/2014
Car air conditioners operate in all seasons to keep the cabin temperature cool in summer and warm in winter. In summer, for air conditioning systems without humidity sensors, the system cannot maintain a comfortable humidity level because the dehumidification function stops when the compressor stops. However, a system with humidity sensors can maintain a comfortable level because the system operates with on/off switching control of the compressors based on the information of humidity sensors, even when the engine is stopped. In winter, to reduce the heating load, the air conditioning system, in conjunction with the engine, controls defogging of the windshield using humidity sensors in addition to reducing ventilation loss by increasing the recirculation rate. By adding humidity information, the control of humidity in summer and defogging in winter can minimize the operation of compressors and the engine, and lead to improved fuel consumption without loss of comfort. In particular, in
Magazine Article
Icing Process of Supercooled-Water Droplet Moving on a Surface by Using Luminescent Temperature-Imaging Technique2013-01-221009/17/2013
An icing process of a single supercooled-water droplet is focused in the present study. A stationary icing as well as an icing of a moving droplet gives us great insights into the development of an ice-prevention system for engineering purpose. For academic purpose, it gives experimental findings in a two-phase flow. To understand the icing process, we applied a luminescent imaging technique. It uses a temperature-sensitive luminophore and a temperature-insensitive luminophore to create the luminescent water. The luminescent outputs from these luminophores are simultaneously captured by a high-speed color camera. By simply taking a ratio, the temperature distribution can be extracted. In this paper, this imaging system is shown with its temperature characterization. An icing process of a stationary droplet is shown in this paper. Also, a current status of an icing process of a moving droplet is shown.
Tanaka, Mio, Morita, Katsuaki, Kimura, Shigeo, Sakaue, Hirotaka
Technical Paper
“Blue” Light Could Help Teenagers Combat StressTBMG-1521211/01/2012
Adolescents can be chronically sleep deprived because of their inability to fall asleep early in combination with fixed wakeup times on school days. According to the Centers for Disease Control (CDC), almost 70 percent of schoolchildren get insufficient sleep, which is defined as less than eight hours on school nights. This type of restricted sleep schedule has been linked with depression, behavior problems, poor performance at school, drug use, and automobile accidents. A new study from the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute shows that exposure to morning short-wavelength “blue” light has the potential to help sleep-deprived adolescents prepare for the challenges of the day and deal with stress, more so than dim light.
Magazine Article
The HVAC Challenge for EVsFA-BB-AUG0208/01/2012
Given the difference in range between a pure electric car and a gas-powered vehicle, it’s absolutely critical that every EV component be as efficient as possible. Auto engineers work hard to ensure that power needed for non-propulsion tasks—such as heating and cooling the cabin, lighting and infotainment—do not unnecessarily drain precious energy from the battery pack. “You want to be careful with how you use every single electron,” said Henning Lohse-Busch, research engineer at the Department of Energy’s Advanced Powertrain Research Facility at Argonne National Laboratory. Among the various potential draws on energy, heating the cabin requires more power than any other function. “If you want to jump straight to the big culprit, it’s the cabin heater,” said Lohse-Busch.
Berman, Bradley
Magazine Article
PRTs and Their Bonding for Long-Duration, Extreme- Temperature EnvironmentsTBMG-1357505/01/2012
Research was conducted on the qualification of Honeywell platinum resistance thermometer (PRT) bonding for use in the Mars Science Laboratory (MSL). This is the first time these sensors will be used for Mars-related projects. Different types of PRTs were employed for the Mars Exploration Rover (MER) project, and several reliability issues were experienced, even for a short-duration mission like MER compared to MSL. Therefore, the development of a qualification process for the Honeywell PRT bonding was needed for the MSL project. Reliability of the PRT sensors, and their bonding processes, is a key element to understand the health of the hardware during all stages of the project, and particularly during surface operations on Mars. Three extreme temperature summer season cycles and three winter season cycles (total: 1983 thermal cycles) were completed, and no Honeywell PRT failures associated with the bonding process were found.
Magazine Article
PRTs and Their Bonding for Long-Duration, Extreme- Temperature EnvironmentsTBMG-TB-01357505/01/2012
Research was conducted on the qualification of Honeywell platinum resistance thermometer (PRT) bonding for use in the Mars Science Laboratory (MSL). This is the first time these sensors will be used for Mars-related projects. Different types of PRTs were employed for the Mars Exploration Rover (MER) project, and several reliability issues were experienced, even for a short-duration mission like MER compared to MSL. Therefore, the development of a qualification process for the Honeywell PRT bonding was needed for the MSL project. Reliability of the PRT sensors, and their bonding processes, is a key element to understand the health of the hardware during all stages of the project, and particularly during surface operations on Mars. Three extreme temperature summer season cycles and three winter season cycles (total: 1983 thermal cycles) were completed, and no Honeywell PRT failures associated with the bonding process were found.
Magazine Article
SAE Clean Snowmobile Challenge Promo 20121105202/10/2012
SAE Clean Snowmobile Challenge Promo.2012. Shot this entirely at the Michigan Technological University Keweenaw Research Center in Winter 2011 (and a very small amount in 2009), at the annual Clean Snowmobile Challenge there, created by the SAE.
Video
Location of Atomizer of Ether Systems for Diesel EnginesJ2079_201110 (Current)10/27/2011
This SAE Information Report recommends the requirements for the location of ether atomizers.
Common Tests Technical Steering Committee
Information Report
Ford charges up Focus EV for 201311AEID1004_0310/04/2011
With major engineering support from Magna, Ford's first battery-electric passenger car promises Leaf-blowing features including half the charge time as that claimed by Nissan using a 240-V SAE J1772 Class 2 charge source. Ford's Global C1 platform is rapidly turning into one of the industry's most flexible and prolific vehicle architectures. By the middle of next year, the automaker will have doubled its production of C-segment vehicles from the approximately one million units built in 2009. The Focus nameplate will represent the largest chunk of those two million vehicles, its annual production volumes expected to exceed 850,000 units globally, according to IHS Automotive. Electric-vehicle advocates might hope that even a fraction of Focus's global scale will rub off on the Focus Electric model that's due to enter production next spring at the Wayne, MI, assembly plant. The 2013-model battery-electric, five-door hatchback is among five electrified vehicles the automaker is launching
Brooke, Lindsay
Magazine Article
Soil Stress State Under Loads of Commercial Vehicles2011-01-217309/13/2011
The paper contains experimental results of soil stress state under loading of commercial wheeled vehicles. The measurements were performed with the use of SSTs (Stress State Transducers), which enable to determine soil pressures needed for calculations of stress state at a point: principal stresses and their direction cosines as well as octahedral stresses. A detailed description of the measuring method with an introductory theory of operation of the SST together with some methodology aspects of soil pressure measurements are included. The field tests were conducted on three different soil surfaces: loess, sand and turf as well as on snow surface in winter conditions. For the tests, two vehicles were used: a 5,6T 4x4 truck and a 14T 6x6 truck. The vehicles were driven at constant low speed or at different speeds. Moreover, effects of wheel loading, reduced inflation pressure, drive modes (rolling or driving) were also analyzed. The results are presented partially in a form of stress
Pytka, Jaroslaw
Journal Article
Check Corp. - Economic trends drive seat heater growth10OFHD0803_0108/03/2010
Executive Viewpoints-Vehicle Development Insights from Industry: Driving Factors for Future Innovation. There are many trends that shape product development and help our industry decide the right areas to focus our efforts. At Check Corp., we realize that today's economic situations are a key driving factor in tomorrow's sales. As many businesses are aware, the agricultural industry has taken an economic hit in recent years. It is facing new challenges on how to increase productivity while decreasing costs. Companies are holding onto equipment for longer periods of time, making cost-saving choices on which options to consider, and even looking for ways to increase employee productivity.
Stuef, Tom
Magazine Article
Improved OTEC System for a Submarine RobotTBMG-TB-00796105/01/2010
This system supplants a related, previously proposed OTEC system. An ocean thermal energy conversion (OTEC), now undergoing development, is a less-massive, more-efficient means of exploiting the same basic principle as that of the proposed system described in “Alternative OTEC Scheme for a Submarine Robot” (NPO-43500), NASA Tech Briefs, Vol. 33, No. 1 (January 2009), page 50. The proposed system as described previously would be based on the thawing-expansion/freezing-contraction behavior of a wax or perhaps another suitable phase-change material (PCM). The power generated by the system would be used to recharge the batteries in a battery-powered unmanned underwater vehicle [UUV (essentially, a small exploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warming. A UUV of this type travels between the ocean surface and depths, measuring temperature and salinity.
Magazine Article
Supercapacitor Electrolyte Solvents With Liquid Range Below –80 °CTBMG-656901/01/2010
A previous NASA Tech Brief [“Low-Temperature Supercapacitors” (NPO-44386) NASA Tech Briefs, Vol. 32, No 7 (July 2008), page 32] detailed ongoing efforts to develop non-aqueous supercapacitor electrolytes capable of supporting operation at temperatures below commercially available cells (which are typically limited to charging and discharging at ≥40 °C). These electrolyte systems may enable energy storage and power delivery for systems operating in extreme environments, such as those encountered in the Polar regions on Earth or in the exploration of space. Supercapacitors using these electrolytes may also offer improved power delivery performance at moderately low temperatures (e.g., –40 to 0 °C) relative to currently available cells, offering improved cold-cranking and cold-weather acceleration capabilities for electrical or hybrid vehicles.
Magazine Article
Modular Electronic Air Sterilization TechnologyTBMG-591411/01/2009
Ultraviolet germicidal irradiation (UVGI) technologies are being used as infection control devices, primarily in healthcare facilities. No standard exists, but the dose of UV and the airflow are critical to ensuring all contaminated air is treated. The UVGI process is mainly influenced by the microorganism population, the irradiation intensity, and the intimate exposure time to the lamps. This new technology enables the system to increase the intensity field or to improve the inactivation process, without adding more energy or increasing the output efficiency of the lamps.
Magazine Article
Wind Effects on Dynamic Stability of Tractor Trailers in Winter Conditions2009-01-291510/06/2009
There is a limited amount of data in literature discussing dynamic instability of tractor trailers due to wind speed and wind gusts on slippery surfaces. This paper outlines an analytical approach to assess tractor trailer performance due to these factors. The paper considers short-period wind gusts as well as uplift effect of the wind, frictional properties of the roadway, vehicle speed, jackknife effects, inertial (both translational and rotational) properties of tractor trailer combinations. Correlation between parameters related to semi dynamic instabilities are offered in a graphical format.
Tremblay, Joe, Ziernicki, Richard, Railsback, Ben, Kittel, Mark
Technical Paper
Determining Surface Roughness in Urban Areas Using Lidar DataTBMG-498103/01/2009
An automated procedure has been developed to derive relevant factors, which can increase the ability to produce objective, repeatable methods for determining aerodynamic surface roughness. Aerodynamic surface roughness is used for many applications, like atmospheric dispersive models and wind-damage models. For this technique, existing lidar data was used that was originally collected for terrain analysis, and demonstrated that surface roughness values can be automatically derived, and then subsequently utilized in disaster-management and homeland-security models.
Magazine Article
Fuel-cell futuresAUTOSEP08_0209/01/2008
Eager to find alternative-propulsion solutions, automakers are betting that renewed emphasis on fuel-cell vehicles will pay off in the long run, with the latest examples aiming to prove higher-volume production feasibility. Hard work by engineers involved in fuel cells continues to eliminate many of the obstacles to the propulsion technology's everyday use in vehicles, which is permitting automakers to launch limited production of prototype models for testing. The engineers are beavering away at the issues affecting practical use-tolerance for cold weather, startup time, power output, and driving range-with advances that have brought fuel cells to nearly the driving experience of vehicles using internal-combustion power.
Carney, Dan
Magazine Article
Deep Space Network Antenna Logic ControllerTBMG-235209/01/2007
The Antenna Logic Controller (ALC) software controls and monitors the motion control equipment of the 4,000- metric-ton structure of the Deep Space Network 70-meter antenna. This program coordinates the control of 42 hydraulic pumps, while monitoring several interlocks for personnel and equipment safety. Remote operation of the ALC runs via the Antenna Monitor & Control (AMC) computer, which orchestrates the tracking functions of the entire antenna.
Magazine Article
AFRL’s Demonstration and Science Experiments MissionTBMG-462008/01/2007
A document describes the Air Force Research Laboratory’s Demonstration and Science Experiments (DSX) mission, dedicated to research needed to advance the ability to operate spacecraft in the harsh radiation environment of medium earth orbit (MEO). The DSX spacecraft, to be launched in late 2009 into an orbit ranging in altitude from 6,000 to 12,000 km, is designed to carry instruments pertinent to studies in three categories:
Magazine Article
The Humidity Validation Payload and Distributed Humidity Control2007-01-320607/09/2007
The Humidity Validation Payload (HVP) has been developed by Orbital Technologies Corporation to validate key humidity and condensate management parameters in microgravity. The thorough understanding of dehumidification efficiency, component lifetimes, and capillary flow leads directly to an optimized, full-scale environmental control system for human-rated vehicles and structures. This paper provides an overview of the design showing the various subsystems and components. Results from initial ground operation are presented and evaluated including dehumidification efficiency and effectiveness. The on-orbit mission objectives are discussed along with the current mission profile and experimental plans for the future. The paper also discusses how this type of system can be applied to large scale environmental control systems using a distributed control system as well as the advantages of this type of approach.
Iverson, Jeffery T.
Technical Paper
Photonic Analog-to-Digital ConvertersTBMG-TB-00459506/15/2007
Speed and resolution limits of all-electronic ADCs would be surpassed. Early steps have been taken toward the development of analog-to-digital converters (ADCs) that would incorporate photonic quantizers based on the technology of InP semiconductors. These photonic ADCs are intended to overcome the sampling speed and temporal resolution limitations of state-ofthe- art all-electronic ADCs, so that outputs of radar and other sensor systems at frequencies as high as tens of gigahertz could be sampled directly, without need for analog signal processing to effect down-conversion in frequency prior to sampling.
Magazine Article
Photonic Analog-to-Digital ConvertersTBMG-459406/01/2007
Early steps have been taken toward the development of analog-to-digital converters (ADCs) that would incorporate photonic quantizers based on the technology of InP semiconductors. These photonic ADCs are intended to overcome the sampling speed and temporal resolution limitations of state-of-the-art all-electronic ADCs, so that outputs of radar and other sensor systems at frequencies as high as tens of gigahertz could be sampled directly, without need for analog signal processing to effect down-conversion in frequency prior to sampling.
Magazine Article
Potential of Thermal Engine Encapsulation on Automotive Diesel Engines2005-24-06709/11/2005
Thermal Engine Encapsulation (TEE) is a technique for reducing heat loss from an engine after it has been switched off, in order to get a warmer re-start. This practice yields benefits in terms of fuel economy, emissions and wear, especially for vehicles used for short journeys in cold weather and with engines warming up slowly. In this study, the encapsulation of a small automotive diesel engine is investigated by means of theoretical and experimental analyses. In particular, the influence of oil temperature on brake specific fuel consumption and emissions is calculated. Furthermore, the thermal behavior of the engine has been simulated by a lumped-capacitance model, in order to assess the correlation between encapsulation thickness and cool-down time. Finally, the 0-D thermal model and the 1-D engine model have been coupled in order to predict the influence of engine cranking temperature on fuel consumption and pollutant emissions, considering a B-class vehicle running a short
Mattarelli, E., Muscio, A.
Technical Paper
Frozen-Plug Technique for Liquid-Oxygen PlumbingTBMG-56806/01/2005
A frozen-plug technique has been conceived as a means of temporarily blocking the flow of liquid oxygen or its vapor through a tube or pipe. The technique makes it possible to perform maintenance, repair, or other work on downstream parts of the cryogenic system in which the oxygen is used, without having to empty an upstream liquid-oxygen reservoir and, hence, without wasting the stored liquid oxygen and without subjecting the reservoir to the stresses of thermal cycling.
Magazine Article
NAIAS supplier guide: what's behind the show carsAUTOJAN05_0101/01/2005
Seductive surfaces and shocking shapes are what catches the eye at this annual winter mega-car-show in Detroit, but functional parts are key to a new model's ultimate success. For automakers, how easy their new cars are on the eyes of media and consumers at events such as this month's North American International Auto Show (NAIAS) in Detroit can have significant impact on how successful individual models are in the future. There's a lot of money riding on those shiny show cars. For suppliers who equip those new cars, however, the beauty of making money is more than skin deep. For them, it's all about functionality. A little flying mud can mar the appearance of even the best-looking car, but it is no threat to the operation of its suspension, exhaust system, or any number of other combat-ready, under-skin systems. Nor does it degrade the performance of the onboard computers and electrical/electronics system. They may not look pretty doing it, but functional components and systems around
Ponticel, Patrick
Magazine Article
Weather Support to Deicing Decision Making (WSDDM) Winter Weather Nowcasting SystemAS5537 (Historical)05/04/2004
The purpose of this SAE Aerospace Standard (AS) is to provide guidelines for the components and configurations that define the four versions of the Weather Support to Deicing Decision Making (WSDDM) winter weather nowcasting system.
G-12M Methods Committee
Technical Standard
Freeze-Tolerant CondensersTBMG-80201/01/2004
Two condensers designed for use in dissipating heat carried by working fluids feature two-phase, self-adjusting configurations such that their working lengths automatically vary to suit their input power levels and/or heat-sink temperatures. A key advantage of these condensers is that they can function even if the temperatures of their heat sinks fall below the freezing temperatures of their working fluids and the fluids freeze. The condensers can even be restarted from the frozen condition.
Magazine Article
Modified Formula for Calculating the Humid Air Enthalpy with the Absolute Zero Temperature as Coordinate's Origin2002-01-244107/15/2002
Existing formula for calculating humid air enthalpy is low sensitive to the changes of water quantity at the vicinity of zero centigrade temperature. Sometimes it may cause increasing errors or computation cycling. To avoid such undesirable phenomena a modified formula has been obtained and suggested.
Shustrov, Y., Starostine, K.
Technical Paper
Rechargeable Li-Ion Cells Containing TiS2 AnodesTBMG-736206/01/2001
Titanium disulfide has been found to be attractive as an alternative to graphite as the anode material in rechargeable lithium-ion electrochemical cells that are required to operate at temperatures below -20 °C. By using TiS2 as the anode material, LiCoO2 as the cathode material, and a suitable low-temperature electrolyte described below, it is possible to construct cells that exhibit superior low-temperature characteristics, including relatively high charge/discharge capacities, capabilities for charging and discharging at relatively high rates, and excellent retention of capacity after repeated charge/discharge cycling.
Magazine Article
Ethyl Methyl Carbonate as a Cosolvent for Lithium-Ion CellsTBMG-736106/01/2001
Magazine Article
Aliphatic Ester Electrolyte Additives for Lithium-Ion CellsTBMG-736006/01/2001
Aliphatic esters have been found to be useful as electrolyte additives for improving the low-temperature performances of rechargeable lithium-ion electrochemical cells. The discovery of the beneficial effects of these additives was made during continuing research directed toward extending the lower limit of operating temperatures of these cells. Other aspects of this research have been described in the immediately preceding article and in prior NASA Tech Briefs articles referenced therein.
Magazine Article
Thruster Based on Sublimation of Solid HydrazineTBMG-709602/01/2001
A report proposes a small spacecraft attitude-control thruster in which the propellant material would be hydrazine that would be stored frozen until sublimed at the instant of use. From the upstream to the downstream end, the main components of the thruster would include a plug of solid hydrazine in a container, a rapid source of radiant heat (e.g., a laser diode or a flash lamp), and a heated-catalyst-and-nozzle assembly like that of a conventional hydrazine thruster. In operation, each pulse of radiant heat would cause a small amount of frozen hydrazine to sublime. The puff of hydrazine vapor thus generated would become chemically decomposed in the heated catalyst, and an impulse would be generated by the expansion of the puff of decomposition products in the nozzle. This thruster would be attractive for generating small impulses (impulse "bits") on command for precise maneuvering of a spacecraft that either remains below the freezing temperature of hydrazine (≈274 K) or that
Magazine Article
Lithium-Based Primary Cells for Low-Temperature OperationTBMG-3010309/01/1999
A report describes an experimental study of the low-temperature electrical characteristics of commercial Li/MnO2, Li/CFx, Li/SO2, Li/SOCl2, and Li/BCX primary electrochemical cells. These high-energy-density cells are under consideration for use as lightweight, compact electric-power sources for scientific instruments in terrestrial polar regions and on Mars, where they could be called upon to operate at temperatures as low as 85 °C. The experiments, performed at temperatures down to - 100 °C, included steady-state current-vs.-voltage measurements during discharges with various increments of load resistance from 105 down to 10 Ω, complete discharge tests, and ac-impedance measurements.
Magazine Article
Influence of Ultrasonic Vibration on Freezing Temperature of Hydrate1999-01-261708/02/1999
The influence of ultrasonic vibration on the freezing temperature of hydrate, disodium hydrogenphosphate 12-water, is investigated for the purpose of the application to long-term thermal energy storage. Four different frequencies and different sound power are tested to the super-cooled material. Experimental results show that the freezing temperature of the hydrate is independent of the cooling rate, and any meaningful change of the freezing temperature is not observed under the ultrasonic vibration. Like other researches on distilled water, the freezing temperature of the hydrate tends to be lower as the volume of the sample becomes smaller.
Hirano, Satoshi, Saitoh, Takeo S., Oya, Masaaki, Yamazaki, Masakazu
Technical Paper
WSDDM“A Real-Time Winter Weather Tool”1999-01-142704/13/1999
Airports and airlines can experience some of the most severe types of weather conditions during the winter season. Winter weather can also adversely affect flight operations as well as flight safety. Severe winter weather, such as freezing rain and snow, is one of the most difficult types of weather phenomenon to predict and prepare for from an airport and airline operations standpoint. Freezing rain and snow affects not only the airport runways, taxiways and aircraft, but the entire airport infrastructure as well, with the potential of incurring long and costly delays. The Weather Support to Deicing Decision Making (WSDDM) system provides help in managing airport ground operations during severe winter weather. WSDDM is a winter weather nowcasting tool that provides real-time meteorological and snow gauge data in a simple, concise, easy to understand nonmeteorological format.
Stanton, Jeffrey C.
Technical Paper
Fuel Warmer-Diesel EnginesJ1422_199611 (Historical)11/01/1996
This SAE Information Report establishes performance requirements for devices used to warm diesel fuel before entering the fuel filter(s). This document applies to all off-road, self-propelled, diesel-powered work machines described in SAE J1116. This document may be applied to other diesel equipment.
CTTC C4, Cold Weather Operation
Information Report
Items per page:
1 – 50 of 104