Browse Topic: Cold weather

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Henrich Focke’s Helicopter Design Lecture at the Technical University of Stuttgart, Winter Semester 1955-56F-0081-2025-00155/20/2025
The biography of Henrich Focke is well known and documented. During a small period from October 1954 to February 1956 he held lectures at the Technical University of Stuttgart during the winter semester. In the summer period he returned to Brazil for continuation of his contract work on the "Convertiplane" (a quad-tiltrotor aircraft) and the "Bei-jaflor" (a small single rotor helicopter). The topic of Focke's lecture in the winter semester 1954-55 was "Design of Fixed-Wing Aircraft", but the lecture manuscript of it is unavailable. In the following period 1955-56 Focke lectured about "Helicopter Design" and the manuscript was recently found in the central archive of DLR. It covers 123 pages of text with sketches and graphs and provides deep insights into the helicopter design philosophy of Henrich Focke.
van der Wall, Berend
An Overview of Applied Methodology in the Gathering and Analysis of Rotorcraft Cold Weather Encounters DataF-0081-2025-04215/20/2025
Civil and military rotorcraft operators desire enhanced capabilities from their vehicles in terms of mission efficiency, effectiveness, productivity, and availability. A critical element of this challenge is associated with providing cold weather availability. Currently, cold weather operations are enabled by regulatory actions leading to Limited Approvals, Qualifications, Clearances, and Restrictions. Cold weather certification (clearance of a new aircraft) and continuing airworthiness (maintaining effectiveness of fielded aircraft) are data driven processes. This work provides guidance on an Icing Encounters Survey (IES) based data gathering method supporting continuing airworthiness organizations in improving fleet safety and capabilities during cold weather operations.
Alexander, Marc
Weather Support to Deicing Decision Making (WSDDM) Winter Weather Nowcasting SystemAS5537A (Current)2/10/2021
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
Cold Weather Testing of the Bell 525 RelentlessF-0076-2020-1636210/5/2020
In the winter months of January-March 2019, two Bell 525 test aircraft completed cold weather testing at Yellowknife Canada, some 1900 nm from Bell’s Flight Research Center in Arlington, TX. Testing was aimed at demonstrating aircraft stability, performance, and flight characteristics at extreme temperatures as required by CFR Part 29. Since regulations only permit limited temperature extrapolation, the cold temperature tests must include the limit of forward speed in a dive (VNE), and assessments of performance, controllability, autorotation, and static stability. This paper describes some of the unique environmental conditions and factors that any rotorcraft development program could experience in cold weather testing. The paper also gives a technical description of the required testing, where arctic conditions reached as low as -40° F or C (the temperature scales are the same at this temperature). Testing exposed the aircraft to overnight cold-soaks that brought fluids, seals, windshields, electronics, and elastomeric bearings to their low temperature specification, all at the same time. For the 525, test results demonstrated that the aircraft was ready for start-up and operation in extreme cold. The criteria necessary for meeting certification requirements in cold weather were also demonstrated in the series of tests and showed that the rotor was free from any adverse effects due to aerodynamic compressibility, had low vibration, acceptable loads and was free from any instability, even at speeds greater than VNE.
Regnier, Bradley, Baden, Joel, Brand, Albert, Lindauer, Patrick, O'Neil, Joshua, Schillings, John
A Design Worthy of Success: Bernard W. Sznycer, Selma G. Gottlieb and the Intercity SG-VIF-0076-2020-1626510/5/2020
As imbedded as it is in technology, the history of flight is also chock full of people stories. The history of the helicopter, one of the most versatile flying machines ever designed, abounds in such stories. This text looks at the development of Intercity Airlines Company's SG Mark VI by a unique team based for a time in Montreal, Quebec. Bernard W. Sznycer and Selma G. Gottlieb conceived one of the most advanced and innovative helicopter of its day. Designed to minimize vibrations and facilitate production, the SG Mark VI first flew in July 1947. Canada's Department of Transport awarded a Certificate of Airworthiness to a second prototype, in April 1951. The SG Mark VI was the first helicopter designed within the British Commonwealth of Nations to be so honored. Sadly, by then, American helicopters all but dominated the civilian and military markets. The SG Mark VI was abandoned during the winter of 1953-54 and both Sznycer and Gottlieb returned to the United States.
Fortier, Renald
Sensor Heat Relief20AVEP03_073/1/2020
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
Guide to Package Integrity & Validation Testing under ISO 11607 and MDRTBMG-350859/1/2019
Updates to ISO 11607, Parts 1 and 2, have left many medical device manufacturers wondering about the future of their packaging designs. These changes come at a stressful time for OEMs, as Europe is also in the process of replacing the current Medical Device Directive (MDD) with the Medical Device Regulation (MDR) in 2020. The interplay between ISO 11607 and MDR is complex, and it’s difficult to predict regulators’ plans for enforcement.
Land Combat MissileTBMG-348608/1/2019
MBDA Incorporated Arlington, VA 703-387-7139
Runway Deicing Product Anti/Deicing Performance Assessment: Review and Future Directions2019-01-19746/10/2019
Every winter, northern airport operations are disrupted by heavy snowstorms and freezing precipitations. A simple snow accumulation or a thin layer of ice can affect aircraft operations (take-off, landing and taxi), and increase the risk for passengers and crew members, by rendering the runway slippery. Any deficits in deicing operations can also lead to flight delays and even cancellations that cost a lot to the industry. In order to maintain the runway and taxiway in a safe and useable condition, airport authorities use mechanical tools, but also chemical products. Chemical products available on the market for use in airports are principally in solid forms and liquid form, and are denominated as Runway Deicing Product (RDP). All of the products used in airport should meet the technical requirements of one of the two Aerospace Materials Specifications (AMS) documents: the AMS1431D Compound, Solid Runway and taxiway Deicing/Anti-icing and the AMS1435C Fluid, Generic, Deicing/Anti-icing Runways and Taxiways. Most of the products are used as freezing point depressants and are applied on snow, ice or packed snow covers to create holes and facilitate the mechanical removal. Over the past ten years, efforts have been brought along to adapt and to develop methods in order to assess the deicing and the anti-icing performance of the products. Some of those methods are included in actual SAE documents and some are in development. This paper will present a review of those methods and also cover the future directions of the research and development in the field.
Brassard, Jean-Denis, Laforte, Caroline, Tremblay, Marc Mario, Volat, Christophe
A Parametric Study on the Thermodynamic Characteristics of DBD Plasma Actuation and Its Potential for Wind Turbine Icing Mitigation2019-01-20316/10/2019
Wind turbine icing represents the most significant threat to the integrity of wind turbines in cold weather. Ice formation on wind turbine blades was found to cause significant aerodynamic performance degradation, resulting in a substantial drop in energy production. Recently developed Dielectric barrier discharge (DBD) plasma-based anti-/de-icing systems showed very promising effects for aircraft icing mitigation. In this present study, DBD plasma-based anti-/de-icing systems were employed for wind turbine icing mitigation. First, a comprehensive parametric study is conducted to investigate the effects of various DBD plasma actuation parameters on its thermodynamic characteristics. An infrared (IR) thermal imaging system is used to quantitatively measure the temperature distributions over the test plate under various test conditions. DBD plasma actuators are embedded over the surface of a DU91-W2-250 wind turbine blade model, and a series of experiments were conducted by using the Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT) to evaluate the anti-/de-icing performance of the system for wind turbine icing mitigation. Dynamic anti-icing process was recorded by a high-speed imaging system, and an IR thermal camera was used to map the temperature distributions over the surface of the wind turbine blade model during the anti-/de-icing processes.
Kolbakir, Cem, Gao, Linyue, Liu, Yang, Hu, Hui
A Three-Layer Thermodynamic Model for Ice Crystal Accretion on Warm Surfaces: EMM-C2019-01-19636/10/2019
Ingestion of high altitude atmospheric ice particles can be hazardous to gas turbine engines in flight. Ice accretion may occur in the core compression system, leading to blockage of the core gas path, blade damage and/or flameout. Numerous engine powerloss events since 1990 have been attributed to this mechanism. An expansion in engine certification requirements to incorporate ice crystal conditions has spurred efforts to develop analytical models for phenomenon, as a method of demonstrating safe operation. A necessary component of a complete analytical icing model is a thermodynamic accretion model. Continuity and energy balances are performed using the local flow conditions and the mass fluxes of ice and water that are incident on a surface to predict the accretion growth rate. In this paper, a new thermodynamic model for ice crystal accretion is developed through adaptation of the Extended Messinger Model (EMM) from supercooled water conditions to mixed phase conditions (ice crystal and supercooled water). A novel three-layer accretion structure is proposed and the underlying equations described. The EMM improves upon the original model for airframe icing, the Messinger Model, by permitting a linear temperature gradient through the ice and water layers. This in turn allows prediction of the time over which water exists in isolation on an initially warm surface, before an ice layer forms. This is of particular interest to engine icing, as surfaces may initially be significantly above freezing temperature, before cooling on exposure to ice particles. The method is solved in a multi-step approach, where the overall exposure time is divided into discrete windows, and the calculation performed over each window. This allows the local flow conditions to be updated between windows, permitting the incorporation of a reducing flow enthalpy due to particle evaporation, as well as transient engine operation. Model results are then compared to experimental results. Comparisons are made to solutions generated using the standard Messinger Model.
Bucknell, Alexander, McGilvray, Matthew, Gillespie, David, Jones, Geoffrey, Collier, Benjamin
Quantification of 3D Ice Structures Accreted on a Wind Turbine Airfoil Model2019-01-20306/10/2019
Accurate quantification of 3D shapes of the complex ice structures accreted on wind turbine blades is highly desirable to develop ice prediction models for more accurate prediction of the aerodynamic performance degradation and power reduction due to the ice accretion on wind turbine blades. In the present study, an experimental investigation was conducted to quantitatively characterize the 3D shapes of the ice structures accreted over a DU91-W2-250 wind turbine airfoil model in the Icing Research Tunnel available at Iowa State University (ISU-IRT). A glaze icing condition and a rime icing condition that wind turbines usually experience in winter were duplicated by using ISU-IRT. A high-resolution non-intrusive 3D scanning system was used to make detailed 3D-shape measurements to quantify the complicated ice structures accreted on the wind turbine airfoil model as a function of the ice accretion time. The measurements results show that the complex 3D shapes of the ice structures accreted over the surfaces of the airfoil model under both glaze icing and rime icing conditions were well captured. It is found that the glaze ice accretion has stronger 3D features, in comparison to the rime ice accretion case, due to its wet nature. The measured 3D shapes of the complex ice structures at different ice accretion moments were also provided to demonstrate the progressive shape changes of the ice structures during the dynamic ice accretion process.
Gao, Linyue, Veerakumar, Ramsankar, Liu, Yang, Hu, Hui
Characterization of Mode-II Interfacial Fracture Toughness of Ice/Metal Interfaces2019-01-19476/10/2019
Airborne, marine and ground structures are vulnerable to atmospheric icing in cold weather operation conditions. Most of the ice adhesion-related work have focused on the mechanical ice removal strategies because of practical considerations, while limited literature is available for fundamental understanding of the ice adhesion process. Here, we present a fracture mechanics-based approach to characterize interfacial fracture parameters for the shear behavior of a typical ice/aluminum interface. An experimental framework employing two complementary tests (1) lap shear and (2) shear push-out tests was introduced to assess the mode-II fracture parameters for the selected aluminum/ice interface. Both analytical (shear-lag analysis) and numerical (finite element analysis incorporating cohesive zone method) models were used to evaluate shear fracture parameters. The combined experimental and numerical results, as well as surveying published results for lap shear and 0° cone tests showed that mode-II interfacial strength and toughness can be significantly affected by the method of testing geometry due to geometrically induced interfacial residual stress. As a result, the apparent toughness (or strength) obtained by 0° cone test could reach an order of magnitude higher than those derived from lap shear test.
Yavas, Denizhan, Bastawros, Ashraf, Dawood, Bishoy, Giuffre, Christopher
Numerical and Experimental Investigation of Ice Adhesion Using the Blister Test2019-01-19486/10/2019
Structures in cold weather environments are susceptible to atmospheric ice formation. A fracture mechanics based approach is proposed for in situ characterization of the interfacial fracture energy of ice on different substrates. This paper summarizes the development of the experimental and analytical framework to measure the ice adhesion energy, calibrated on static ice. The testing configuration utilizes a shaft-loaded blister test to produce stable crack propagation, from a well-defined pre-crack at the interface of the ice layer and the substrate. Measurements of the fracture energy are taken over a range of ice thicknesses and surface roughnesses. The developed analytical framework to estimate adhesion energy are verified and calibrated via finite element numerical simulation of the proposed geometric configuration and employing cohesive surfaces along the interface to simulate the crack nucleation and propagation process. Several different phenomena were observed include the transition from adhesive to cohesive fracture. The measured interfacial adhesion energy was almost independent of the surface roughness in the range of examined roughness. The measured interfacial R-curve showed a steady state plateau for range of interfacial crack propagation. The proposed experimental framework enables precise measurement of the interfacial fracture toughness over a range of surface finishes and ice layer thickness.
Giuffre, Christopher, Dawood, Bishoy, Yavas, Denizhan, Bastawros, Ashraf
Automotive Engineering: June 201919AUTP066/6/2019
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 dragon ICE researchers: 50% gasoline-engine efficiency in sight EMBATT looks to double the driving range of EVs Ford amped for new phase of hybrid-electric offensive As automotive climates shift, GKN ramps up its winter testing Mazda finally ready with Skyactiv-D for U.S. 2020 Escape: Ford's first crossover on new global FWD architecture New design for 2020 Mitsubishi Outlander Sport as brand awaits alliance's new platforms, products
Battery Provides Electric Vehicles with Immunity from Climate ConditionsTBMG-3341412/1/2018
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.
Aerogel Insulation Makes Thinner, Warmer OuterwearTBMG-3320611/1/2018
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.
Artificial “Blubber” Protects Divers in Frigid WaterTBMG-324828/1/2018
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.
Flight Awareness Collaboration Tool (FACT)TBMG-288565/1/2018
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.
Thermal Model of High-Power Lithium Ion Battery Under Freezing Operation2018-01-04454/3/2018
Lithium ion battery is considered as one of the most possible energy storage equipment for new energy vehicles (EV, HEV, etc.) because of the advantages of long cycle life, high power density and low self-discharge rate. However, under freezing condition high power battery suffers of significant performances losses. For example, they would suffer from significant power capability losses and poor rate performance, which would restrict the availability to delivery or to gain of high current in transient conditions. To evaluate those performance drawbacks and to make an efficient design, good mathematical models are required for system simulation especially for battery thermal management. In this paper, a three-dimensional homogenization thermal model of a 20 Ah prismatic lithium ion battery with LiFePO4 (LFP) cathode is described. This model particularly stresses on the high-ratio discharge property at low-temperature which could capture the shapes and dimensions of cell components and the spatial distributions of the temperatures. First, various discharge tests on one cell are carried out, and then, cell’s parameters and thermal characteristics are obtained. Ultimately, the three-dimensional thermal model for single-cell proposed is shown to be accurate by analyzing the simulation data and test results.
Xuan, Tang, Wei, Xuezhe, Dai, Haifeng, Venturi, Massimo
Zinc Alloy Ingot and Die Casting CompositionsJ468_201801 (Current)1/9/2018
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
Multi-Functional Yarns and Fabrics with Anti-Microbial, Anti-Static, and Anti-Odor CharacteristicsTBMG-2801212/1/2017
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.
Characterization and Discrimination of Aircrafts and Runways Winter Maintenance Anti-Icing Fluids2017-01-21409/19/2017
Aircrafts and runways de-icing operations with anti-icing fluids are still the most commonly used methods. In the specific case of aircrafts, they do contain glycols. Nevertheless, since two decades now, major environmental concerns are raised, along with important associated costs. Furthermore, once applied either on aircrafts or on runways, these fluids are diluted because of water brought from adverse weather conditions (rain, snow, icy conditions), conducting to increasing the freezing point from a subzero level to 0°C. The characterization of the freezing points of these fluids is indeed crucial for safety reasons. For years now, Raman spectroscopy is used for the characterization of these fluids, specifically the freezing point. But the presence of dyes did perturb the usual spectroscopic characterization. Three fluids, from their pure commercial form to highly diluted rate, were then studied by means of Raman spectroscopy at a new laser wavelength, and with the support of multivariate data analysis (MDA). Each fluid belonged to a specific type of aircraft anti-icing fluid (I, II and IV). The discrimination of the fluids between each other was obtained. Spectroscopic data was organized through MDA in such a way that neither the presence of a dye nor the dilution would allow any confusion. The identification of the evolution of freezing temperatures with dilution was elaborated, with their rapid increase as dilution increased too. MDA allowed also the elaboration of prediction models, and such tool conducted to the forecast of concentration in anti-icing, or of its freezing temperature on the basis of the Raman signature of the considered fluid, with a given degree of confidence.
Marchetti, Mario, Casteran, Guillaume, Jobard, Celine, Saintot, Bruno, Bourson, Patrice, Fontana, Marc
Real-Time Robust Lane Marking Detection and Tracking for Degraded Lane Markings2017-01-00433/28/2017
Robust lane marking detection remains a challenge, particularly in temperate climates where markings degrade rapidly due to winter conditions and snow removal efforts. In previous work, dynamic Bayesian networks with heuristic features were used with the feature distributions trained using semi-supervised expectation maximization, which greatly reduced sensitivity to initialization. This work has been extended in three important respects. First, the tracking formulation used in previous work has been corrected to prevent false positives in situations where only poor RANSAC hypotheses were generated. Second, the null hypothesis is reformulated to guarantee that detected hypotheses satisfy a minimum likelihood. Third, the computational requirements have been greatly reduced by computing an upper bound on the marginal likelihood of all part hypotheses upon generation and rejecting parts with an upper bound less likely than the null hypothesis. Therefore, parts that could never surpass the null hypotheses are excluded from contributing to the n2 complexity of the tracking and pairing processes. These improvements have led to real-time operation at the frame rate of the stereo camera and robust detection results on the evaluation dataset. The evaluation and training datasets were obtained from geographically distinct regions, both with significantly degraded lane markings.
Smart, Michael, Vaishnav, Satish, Waslander, Steven
Robust 1D Modelling for Automotive HVAC Warmup Prediction Using DFSS Approach2017-01-01793/28/2017
In an automotive air-conditioning (AC) system, the heater system plays a major role during winter condition to provide passenger comforts as well as to clear windshield defogging and defrost. In order to meet the customer satisfaction the heater system shall be tested physically in severe cold conditions to meet the objective performance in wind tunnel and also subjective performance in cold weather regions by conducting on road trials. This performance test is conducted in later stage of the program development, since the prototype or tooled up parts will not be available at initial program stage. The significance of conducting the virtual simulation is to predict the performance of the HVAC (Heating ventilating air-conditioning) system at early design stage. In this paper the development of 1D (One dimensional) model with floor duct systems and vehicle cabin model is studied to predict the performance. Analysis is carried out using commercial 1D simulation tool KULI®. All the simulation parameter which affects the correlation process has been studied carefully by using DFSS (Design for six sigma) methodology. L18 orthogonal array developed to understand the influence of each simulation parameters. Data analysis is carried out from DFSS study output and identified the importance of each simulation parameters which is being adjusted for correlation. This methodology helps to predicts accurately for any change in the HVAC heater systems circuit components like heater core, heater core inlet coolant flows, heater core inlet coolant temperatures, heater core airflow etc. This study enhances to reduce the number of physical tests, prototypes and cost involved in it.
Sambandan, Saravanan, Valencia, Manuel, S, Sathish Kumar
Particle Emissions from Light-Duty Vehicles during Cold-Cold Start2016-01-09974/5/2016
To ensure reliable starting under cold weather conditions (< 0 oC ambient), gasoline engines use fuel enrichment, leading to higher soot formation and greater tailpipe particle number (PN) emissions. In gasoline direct injection (GDI) engines, PN emissions are higher due to liquid fuel impingement on cold surfaces of the combustion chamber and piston. This study characterizes solid (mostly elemental carbon) and semi-volatile (organic) particle number, mass, and size distributions during cold-cold engine start-up from light duty vehicles. Particle emissions were sampled from vehicles upon engine start-up after an overnight soak, with an average ambient temperature of -8 ± 7 oC. The average PN emitted during 180 seconds by GDI and PFI vehicles were 3.09E+13 and 2.12E+13 particles respectively. Comparing to 2017 Euro 6 New European Driving Cycle (NEDC) limit on cumulative particles emitted over the entire test cycle, most PFI and GDI vehicles exceeded this limit in 6-12 seconds after a cold-cold start. In addition, EPA Tier 3 particle mass requirements are exceeded for tested GDI vehicles due to their characteristically high concentration of accumulation mode particles. In comparison, diesel vehicles with DPF’s were the cleanest, with particle concentrations close to background levels. Cold-cold starts were followed by a five-minute soak and a second engine start. GDI vehicles’ total emitted PN was almost two to three times that of PFI vehicles during restart. This study highlights the need for better particle control strategies to reduce particle emissions during engine start-up in cold ambient temperatures. Our work also confirms that under cold-cold start conditions, most of the total exhaust particles are solid soot and only a small fraction are semi-volatile.
Badshah, Huzeifa, Kittelson, David, Northrop, William
Analysis of Defogging Pattern on Windshield and Ventilation Load Reduction based on Humidity Distribution Control2016-01-02564/5/2016
In the winter, windshield glass fogging must be prevented through the intake of outdoor air into a vehicle. However, the corresponding energy loss via the ventilation system cannot be ignored. In the present study, the defogging pattern on the windshield is evaluated and the water vapor transportation in the flow field in the vehicle is analyzed in order to investigate the ventilation load by means of a numerical simulation. Some examined cases involve new outlet positions. Additionally, a new, energy-saving air supply method for defogging, with so-called “double-layer ventilator”, is proposed. In this method, one air jet layer is obtained via a conventional defogging opening in the vicinity of the windshield, supplying an outdoor air intake. The other jet consists of recirculated air that covers the outdoor air, preventing it from mixing with the surrounding air. The calculation results indicate that the exhaust opening location, from which the internal vehicle air is obtained for recirculation, affects the cabin flow field, the windshield fogging pattern and the ventilation load. The water vapor generated from human occupants did not spread well and that is why there was the humidity gradient in the vehicle. This means that the flow field must be considered in order to achieve efficient defogging, that is done by emitting the water vapor immediately. The double-layer method exhibits the same level of defogging performance as single-layer techniques, even with half the airflow velocity. The energy load can be reduced by approximately 5 % using the appropriate conditions.
Nagano, Hideaki, Tomita, Kenji, Tanoue, Yasuhiro, Kobayashi, Yuji, Kohri, Itsuhei, Kato, Shinsuke
Effects of the Glass and Body Heat Transfer Characteristics of an Electric Vehicle on its Energy Consumption and Cruising Distance2016-01-02604/5/2016
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 detected and the recirculation ratio of the ventilation was controlled in order to maintain defogging. The effect of the anti-fog control combined with the thermal insulation efficiency of the glass on the cruising performance was examined with the cruising distance estimation method. The results indicated that improving the thermal properties of the glass does not have much effect without the anti-fog control. Hence, anti-fog control enhances the effect of improving the thermal properties of the glass on the cruising distance.
Ozeki, Yoshiichi, Nagano, Hideaki, Kohri, Itsuhei
Microwave-Steam Based Road Deicing Vehicle Focused on Thin Ice Layers2015-01-05024/14/2015
For the thin ice on the road in winter, the traditional road deicing vehicle relies on mechanical and chemical methods for melting ice, which is inclined to damage the pavement and has insidious influence on environment. The thermal deicing vehicle has been adopted in recent years. Although the deicing method is available, the deicing efficiency is unacceptable while the energy consumption is huge. The study adopts the new idea of “bottom-to-top” for melting the intersection area between the road surface and the bottom ice layer by the microwave heating firstly and then cleaning them out using high pres. vapor cutting so as to save the cost of energy and enhance the traffic safety. First of all, the mathematical model of the melting process of the intersection of the pavement and the ice layer was established according to the microwave heating characteristics. Then the mechanism about the compatibility between the steam temperature, saturation and the upper surface of the ice was analyzed. Based on the analysis, the design of the post-process of ice melting was modified. After determining the layout scheme of microwave steam deicing device on vehicles, the analysis energy flow of vehicle was completed in the last. The result shows that the deicing vehicle is viable and its energy consumption is eighty percent as much as the traditional deicing vehicle's for melting the 5mm thin ice layer. There is no water pollution and road surface damage in the whole process.
Xu, Zhicheng, Tan, Gangfeng, Sun, Xingzhi, Ge, Yongqiang, Hua, Min, Xu, Haobo
High Performance Engine Mounts to Suit Various Environment for Automotive Application2014-01-286510/13/2014
Success of the vehicle in cold countries depends on performance of the vehicle under cold climatic conditions. In automobiles, structural elastomer components have strong influence on vehicle performance including NVH, ride comfort & durability. Elastomers are sensitive in nature to these climatic conditions due to its temperature dependent visco-elastic behavior. Thus, it is very important to understand structural elastomer component's performance at sub zero temperatures. In a vehicle, Engine mount is used to hold engine firmly and isolate vibrations away from chassis. Vibration isolation of a mount at low temperature is generally affected by the rubber composition. Major ingredients of the rubber composition influencing the low temperature characteristics are Elastomer type, filler type, plasticizer and curing system. Rubber composition plays key role in achieving engine mount properties like static stiffness, dynamic stiffness, permanent set and durability. In this work, influence of low temperature has been successfully evaluated for engine mount application by varying elastomer type, filler type, plasticizer and curing system. Subject work led to successful evaluation of various rubber formulations to meet desired functional targets and requirements.
Sivakumar, Anandan, Saishanker, V., Gopal, Raghvendra
Monoglyceride Content in Marine Diesel Fuel-A Guide2014-01-277510/13/2014
Problems with the low-temperature operability performance of biodiesel in blends with petroleum diesel are infrequent, but continue to limit the use of biodiesel during winter months. A troubling aspect of this problem is that in some cases precipitates above the blend Cloud Point (CP) have been detected and have led to plugging of fuel filters and subsequent engine stalling, as well as plugging of fuel dispenser filters. Many researchers found that the saturated monoglyceride content was a main component of the material that was found on plugged fuel filters, as well as traces of Saturated DiGlycerides (SDG), were also present on the plugged fuel filters. This is the reason which forced the organization of standardization to suggest a procedure in order to predict the content of the Saturated MonoGlycerides (SMG) even with uncertainty which can vary from −50% to +50%. The model which was used will be the same as that which was introduced in the Annex C of EN 14214+A1:2013. The model is based on the assumption that saturated fatty esters, saturated fatty acids and saturated monoglycerides are present in the same concentration levels in the FAME. The present work will give a guide with the prediction of the saturate monoglyceride in the distilled marine diesel fuel according to ISO 8217 depending on the operating climate requirements. The target is to provide a guide to understand the difference between the various climate conditions with respect to marine diesels potential cold flow performance.
Kalligeros, Stamatios Spyridon, Zannikos, Fanourios, Lois, Evripidis, Anastopoulos, George
Diesel Fuel Filter Designs for Cold Weather2014-01-271110/13/2014
Cold weather is a challenge for compression ignition engines. As Diesel fuel creates wax crystals when temperature goes down enough, it comes to plug the fuel filter and the fuel injection system, leading to undesirable effects like loss of power, engine stall after start or even the engine not starting at all. Moreover, it has been shown that FAME Biodiesel has additional negative impacts on vehicle cold flow operability. Despite fuel additives which can support cold conditions, the whole fuel injection system has to be designed to support engine operability in variable environments, meaning also in very cold conditions, with variable fuel qualities. The Diesel Fuel Filter is a key element of the fuel injection system, as it could become to get plugged by wax and deposit formed at cold temperatures. This can generate fuel shortage on the common rail and high pressure fuel injectors. Addressing this filter plugging effect, can be crucial for vehicle operability. In order to understand and quantify the cold fuel flow impact on the Diesel fuel filter, a design of experiment has been set-up and achieved. Various fuels, filter geometries and filter media have been evaluated all together in order to identify the key parameters which impact the cold flow properties. Thanks to that, some design guidelines have been defined. This should permit to adapt filter designs, in accordance with environment constraints, in order to propose the best vehicle operability, even in very cold conditions using worst cold sensitivity Biodiesels.
Arnault, Nicolas, Monsallier, Guy
Compilation of Freezing Brake Experience and Suggested Designs and Operating Procedures Required to Prevent Its OccurrenceAIR4762 (Historical)8/20/2014
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
DEF Storage and Delivery System for Operation in Extreme Winter Conditions2014-01-15304/1/2014
Automotive SCR systems are dimensioned to reduce NOx efficiently in normal driving conditions. In markets such as North America and Europe, extreme winter conditions are common over a period of many weeks where temperatures are usually below DEF (Diesel Exhaust Fluid) freezing temperatures at −11°C (12°F). In previous studies and applications, DEF was heated in the tank in a dedicated pot or alternatively by a standardized central heater. Due to the local character of these heating solutions, it was not possible to thaw the full tank volume. The objective of this study is to demonstrate how to significantly improve performance of the SCR system in cold weather conditions for passenger car, light commercial vehicles and SUV applications. The performance improvement is demonstrated by sustainability testing showing how much of the full tank content can be thawed and made available for injection in the exhaust system. Based on maximum average dosing rates of 250 g/h, external temperatures down to −40°C and depending on the tank shape the heater is designed to optimize tank heating performance. Once the prototype is made, tests are performed to confirm the real system performance in these extreme conditions. Test results show the capability of the heating system to reach more than 90% of the tank volume and to ensure that liquid DEF is available for injection, even at the maximum average dosing rate of 250 g/h.
Op de Beeck, Joel, Slusser, Kevin, Booth, Neall
A Coupled Numerical Model to Predict Heat Transfer and Passenger Thermal Comfort in Vehicle Cabins2014-01-06644/1/2014
Cabin heating and cooling loads of modern vehicles, notably electrically driven, represent a major portion of the overall vehicle energy consumption. Various concepts to reduce these loads have thus been proposed but quantitative experimental analysis or numerical predictions are scarcely available. Conventional 1D or zonal cabin models do not account adequately for strongly inhomogeneous cabin climate conditions. In this paper a new cabin model is presented, which delivers both temporally and spatially resolved data. The model uses a dynamic coupling algorithm including a CFD simulation of the cabin airflow, a model of the cabin structure and the detailed passenger Fiala Physiological Comfort (FPC) model. The coupling not only includes heat transport between the cabin air and the surrounding surfaces, but also considers important interactions with the occupants, including e.g. the release of moisture into the cabin air by respiration and sweating predicted by the Fiala Physiological Comfort model and the heat exchange between occupant body parts and solid surfaces by radiation and conduction. The coupled model was validated by an experiment conducted in a climate chamber with 22 human test subjects, to assess the effect of local measures such as seat heating in a cold environment on surface temperatures, thermal sensation and comfort. The performance of the coupled model and the effect of concepts to reduce the heating energy demand and enhance thermal comfort, such as a low emissivity window coating, seat and panel heating, are demonstrated as two sample test cases at cold weather conditions.
Lorenz, Manuel, Fiala, Dusan, Spinnler, Markus, Sattelmayer, Thomas
Capacitive Humidity Sensors Using Highly Durable Polyimide MembraneTBMG-193664/1/2014
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 order to prevent energy loss, it is necessary to sense the humidity around windshields to prevent windshields from fogging up in winter.
High-Volume Ethanol Fuel Composition Optimized for Cold Driving Conditions2013-01-261310/14/2013
VTT (Technical Research Centre of Finland) has together with the Finnish energy company St1 tested different high-volume ethanol fuel (E85) samples in order to find the optimum composition for this fuel to perform satisfactorily in low ambient temperature driving conditions encountered in Finland quite frequently during the winter season. Altogether six different fuel compositions were evaluated, with 70 to 85 % of anhydrous bioethanol, and various different mixes of regular petrol components and some specific species like ETBE, butane, etc. As a reference, new Euro-quality 95 RON petrol with 10% ethanol was used. Volatility of each sample was adjusted according to test temperatures to match summer or winter condition and to ensure effortless start-up. Test results showed that the composition of the fuel had marked influence on emissions. The lower the test temperature was, the more distinctive were the differences. Already at −7°C with “straight” E85 mixture composed of ethanol and petrol, the unburned hydrocarbon emissions were very high. On the other hand the more “engineered” fuels performed much better, and allowed starting as low as at −20 to −25 °C. Cold start and driving was possible at equal level of unburned hydrocarbons and other unwanted emission species (such as aldehydes) at an ambient temperature about 10 °C lower compared to “straight” E85 fuel.
Laurikko, Juhani, Nylund, Nils Olof, Aakko-Saksa, Paivi
Optimization of Cold Start Operating Conditions in a Stoichiometric GDI Engine with Wall-guided Piston using CFD Analysis2013-01-265010/14/2013
The purpose of this paper is to investigate the mixture formation and optimize the operating conditions under cold start in a stoichiometric (λ=1) GDI engine with wall-guided piston using a 3D commercial code, STAR-CD [8]. For GDI engine under cold start, it can be difficult to carry out the optimization of operating conditions by engine test alone without the understanding of mixture formation inside the combustion chamber. In this study, three cold start conditions of the catalyst heating mode with split injection, the cranking under freezing temperature and acceleration before engine warm-up which causes oil dilution were calculated. In particular, injection strategy for each cold start condition were optimized and compared to the engine test data. The previously validated spray models [6] were applied to the analysis of the spray formation and mixing process inside the combustion chamber. Also, Bai's droplet-wall interaction model and liquid film model considering the film stripping on the surface were used for better prediction of wall film behavior. This approach reasonably predicts the interaction of the injected spray and the in-cylinder flow, the mixture distribution around the spark plug, and liquid film on the wall inside the combustion chamber. The analysis results show that under cold start with relatively low engine speed, injection parameters such as pressure, split injection ratio and timing strongly affect tumble flow, mixture formation and wall wetting. The results for the optimized injection conditions are qualitatively in good agreements with experimental data in terms of combustion stability (RPM variation), HC emission, and oil dilution.
Kim, Sung-Jun, Hyun, Soungjae, Park, JaeIn
De-Icer Quantification and Phase Transition Detection by Raman Spectroscopy2013-01-21019/17/2013
Winter maintenance is based on the intervention of operating services, as well as the use of deicers. Each year, in France, thousands of tons of deicers are spread through runways and taxiways. On the airport sector, the main deicers are sodium or potassium acetates and formates. All these deicers aim to prevent ice formation (preventive strategy) and/or improve the ice melting of snow residual film (curative strategy) at temperatures below 0°C. The operating principle of these compounds is based on the lowering of the solution's freezing point once dissolved in water. The phase diagram's knowledge is predominant to determine the deicer's amount to be applied on the surface. It provides a way to optimize their amounts applied with respect to weather conditions, present or forecasted. The Center for Technical Studies of Equipment in East of France (CETE de l'Est) developed and implemented a method based on Raman spectroscopy to characterize aqueous solutions of airport de-icers. This application determines the phase transition temperatures of these solutions, according to their concentration. The spectroscopic tool being portable, its use could be easily conducted on the field, avoiding any sample collections. Furthermore, this spectroscopic tool enables the determination of the amount of de-icers used to generate the solution. This study also highlighted some differences between the freezing curves of different deicers, as well as the possible presence of phases with unknown chemical and mechanical properties, such as the metastable phase potassium formate. Additional lessons related to winter maintenance could be taken, on the shelf-life of these products as an example.
Durickovic, Ivana, Marchetti, Mario, Poissonnier, Stephanie, Casteran, Guillaume, Mansour, Rachel, Schweigert, Nathalie, Mars, Benoit
The Development of FR-Based 4WD Multi-Link Suspension2013-01-12354/8/2013
In this paper FR (Front Engine, Rear wheel Drive) based 4WD 5-link independent suspension systems are introduced which are developed for low friction road stability in the winter. The arrangement of the lower control arm of the newly developed suspensions has been changed in order to correspond to 4WD layout. And basic performance is satisfied due to the addition of the driveline. Also NVH (Noise, Vibration and Harshness) performance has improved, to enhance the comfort of the vehicle
Jung, DaeWoo, Lee, Jae Kil, Lee, Byung-Kyu, Kim, Seon Pyung
“Blue” Light Could Help Teenagers Combat StressTBMG-1521211/1/2012
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.
Diesel Vehicle Cold Operability: Design of Fuel System Essential Besides Fuel Properties2012-01-15929/10/2012
Cold operability is estimated by fuel's cold filter plugging point (CFPP). However, correlation of CFPP with diesel vehicle performance originates from a period when simple in-line or distributor fuel injection systems were applied and fuels did not contain biocomponents. Today, common rail fuel injection systems are used and there seem to be remarkable differences in their design between vehicle models. Seven cars were tested in a climate chamber. The best cars operated down to 8°C below fuel's CFPP but the worst get into problems 5°C above CFPP with the same fuel. It is challenging to define what CFPP is needed in order to guarantee trouble-free winter performance because there are big differences between car models. It is fundamental to get the fuel temperature of a vehicle's fuel filter above the fuel's cloud point during driving, and this depends on fuel system design factors, such as location and size of fuel filter and fuel heater if it is used. Oil companies prefer diesel fuels which do not have unnecessary good cold properties because better cold properties reduce the diesel fuel yield at refineries at a time when there is shortage of diesel fuels in Europe. Light middle distillate fractions suitable for winter grades are needed also for aviation kerosene production. Cold operability problems related to biocomponents can be avoided by using isomerized HVO. Trouble-free operation in cold conditions is important for all stakeholders: oil companies, automotive companies and vehicle owners. Further exchange of information and cooperation between oil, automotive and fuel additive companies would be valuable as well as more vehicle testing.
Mikkonen, Seppo, Kiiski, Ulla, Saikkonen, Pirjo, Sorvari, Jari
PRTs and Their Bonding for Long-Duration, Extreme- Temperature EnvironmentsTBMG-135755/1/2012
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.
Development of System Control for Rapid Warm-up Operation of Fuel Cell2012-01-12304/16/2012
Cold weather operation has been a major issue for fuel cell hybrid vehicles (FCHV). To counteract the effects of low temperatures on FCHV operation, an approach for rapid warm-up operation based on concentration overvoltage increase and conversion efficiency decrease by limiting oxygen or hydrogen supply was adopted. In order to suppress increases in exhaust hydrogen concentration due to pumping hydrogen during rapid warm-up, dilution control using bypass air and reduction of concentration overvoltage by a minimum voltage guard were implemented. These approaches effectively control waste heat generation and suppress exhaust hydrogen concentrations during cold start and warm-up. These developments were incorporated into the 2008 Toyota FCHV-adv and it was confirmed that the rapid warm-up operation strategy allowed the FCHV-adv to be successfully and repeatedly started at -30°C.
Naganuma, Yoshiaki, Manabe, Kota, Imanishi, Hiroyuki, Nonobe, Yasuhiro
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
Evaluation of AL 2 O 3 , Graphite and Sulphide Effects on MU Behavior in Different Humidity Environments Through Combined Mixture-Environmental DOE2011-01-23499/18/2011
The friction performance of a Disc Brake Pad is even more required to present stable mu behavior in various environmental conditions such as different temperature and humidity. Interaction between compositional variables (raw materials) and environmental conditions cannot be revealed by a simplistic approach without taking into account their mutual interactions. Thereby is necessary a "crossed" design able to combine mixture components with environmental factors. This paper reports the mu behavior of a commercial Brake Pad Formulation in two different environmental conditions (winter condition, e.g., low humidity, and summer condition, e.g., high humidity) through a Combined Design of Experiment. The design was defined by the variation of three mixture components (Al₂O₃, Graphite and Sulfides) of the Brake Pad Formula according to a Response Surface Method (RSM). The μ behavior has been evaluated on a full-scale dynamometric bench test (AK-Master) with climatic control. The DoE output reports the effect of 7 different compositions at 2 levels of humidity and temperature on the friction performance at different speed, pressure and temperature conditions. Moreover a Physical and Chemical characterization of the 7 different composition brake pads has also been reported.
Merlo, Fabrizio, Passarelli, Umberto, Buonfico, Pietro
Soil Stress State Under Loads of Commercial Vehicles2011-01-21739/13/2011
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 courses and as numerical data of peak maximum stresses under wheels.
Pytka, Jaroslaw
A Freezing Fog/Drizzle Event during the FRAM-S Project2011-38-00286/13/2011
The objective of this work is to better understand freezing fog/drizzle conditions using observations collected during the Fog Remote Sensing and Modeling project (FRAM-S) that took place at St. John's International Airport, St. John's, NL, Canada. This location was ~1 km away from the Atlantic Ocean coast. During the project, the following measurements at one minute resolution were collected: precipitation rate (PR) and amount, fog/drizzle microphysics, 3D wind speed (Uh) and turbulence (Uh'), visibility (Vis), IR and SW radiative fluxes, temperature (T) and relative humidity (RH), and aerosol observations. The reflectivity and microphysical parameters obtained from the Metek Inc. MRR (Microwave Rain Radar) were also used in the analysis. The measurements were then used to obtain freezing fog/drizzle microphysical characteristics and their relation to visibility. The ground-based CIP (Cloud Imaging Probe) measurements of freezing fog/drizzle particles together with hydrometeor measurements obtained from disdrometers have been used in the analysis. During FRAM-S, ice accumulation over the surfaces was more than 2 cm on 26 March 2009 and this affected some of the various sensors but the major instruments worked properly to get freezing fog/drizzle conditions. The results suggested that better prediction techniques for freezing fog/drizzle events are needed for marine environment applications. Particle microphysical measurements play a crucial role for developing better nowcasting/forecasting techniques.
Gultepe, Ismail, Isaac, George A., Rasmussen, Roy Martin, Ungar, K.
Check Corp. - Economic trends drive seat heater growth10OFHD0803_018/3/2010
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
Supercapacitor Electrolyte Solvents With Liquid Range Below –80 °CTBMG-65691/1/2010
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.
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