Browse Topic: Cold weather

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Quantifying the Energy Consumption of HVAC Operation and Its Impact on the Range of Electric Buses Across Diverse Climatic Conditions2026-26-02041/16/2026
Electric buses (e-buses) are essential to sustainable public transport, but their real-world efficiency and range are heavily affected by auxiliary systems, particularly the Heating, Ventilation, and Air Conditioning (HVAC) system. This study investigates how ambient temperature variations and HVAC loads influence energy consumption, range, and efficiency in e-buses operating under diverse climatic conditions. The methodology combines field data collection from urban e-buses across seasons—including extreme summer and winter—with controlled lab testing. Field measurements included ambient temperature, HVAC demand, vehicle speed, state of charge (SOC) variation, and energy consumption. These inputs were used to develop real-world duty cycles, replicating actual thermal loads, passenger profiles, idling periods, and driving patterns. In the lab, these cycles were simulated using a chassis dynamometer and environmental chamber, with HVAC systems tested at controlled ambient temperatures
Vishe, Prashant, Dalela, Saurabh, Joshi, Madhusudan, Saraswat, Shubham
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
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
Army Completes Satellite as a Managed Service Research ProjectTBMG-5213312/1/2024
Intelsat McLean, VA melissa.longo@intelsat.com
Simulation Driven Design of HVAC Systems under Competing HVAC Noise and Defrost Performance Requirements2021-01-10208/31/2021
It is particularly easy to get tunnel vision as a domain expert, and focus only on the improvements one could provide in their area of expertise. To make matters worse, many Original Equipment Manufacturers (OEMs) are silo-ed by domain of expertise, unconsciously promoting this single mindedness in design. Unfortunately, the successful and profitable development of a vehicle is dependent on the delicate balance of performance across many domains, involving multiple physics and departments. Taking for instance the design of a Heating, Ventilation & Air Conditioning (HVAC) system, the device’s primary function is to control the climate system in vehicle cabins, and more importantly to make sure that critical areas on the windshield can be defrosted in cold weather conditions within regulation time. With the advent of electric and autonomous vehicles, further importance is now also placed on the energy efficiency of the HVAC, and its noise. During the development of the defrost mode of an
Nagarajan, Vijaisri, Biermann, Jan, Goldberg, Jens, Motiwala, Hamza, Martins, Diogo, Luzzato, Charles, Mukutmoni, Devadatta
Experimental Validation of Eco-Driving and Eco-Heating Strategies for Connected and Automated HEVs2021-01-04354/6/2021
This paper presents experimental results that validate eco-driving and eco-heating strategies developed for connected and automated vehicles (CAVs). By exploiting vehicle-to-infrastructure (V2I) communications, traffic signal timing, and queue length estimations, optimized and smoothed speed profiles for the ego-vehicle are generated to reduce energy consumption. Next, the planned eco-trajectories are incorporated into a real-time predictive optimization framework that coordinates the cabin thermal load (in cold weather) with the speed preview, i.e., eco-heating. To enable eco-heating, the engine coolant (as the only heat source for cabin heating) and the cabin air are leveraged as two thermal energy storages. Our eco-heating strategy stores thermal energy in the engine coolant and cabin air while the vehicle is driving at high speeds, and releases the stored energy slowly during the vehicle stops for cabin heating without forcing the engine to idle to provide the heating source. To
Amini, Mohammad Reza, Hu, Qiuhao, Wang, Hao, Feng, Yiheng, Kolmanovsky, Ilya, Sun, Jing
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
Photoreceptor System for Melatonin Regulation and PhototherapyTBMG-385002/1/2021
Light is the primary stimulus for regulating circadian rhythms, seasonal cycles, and neuroendocrine responses in many species including humans. During the past 20 years, studies have tested the use of light for treating fall and winter depression (Seasonal Affective Disorder or SAD), non-seasonal depression, sleep disorders, menstrual dysfunction, and eating disorders. In addition, investigators are exploring the use of light for reentraining human circadian physiology relative to the challenge of shift work or intercontinental air travel.
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
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
Regnier, Bradley, Baden, Joel, Brand, Albert, Lindauer, Patrick, O'Neil, Joshua, Schillings, John
Leaf-Inspired Surface Prevents Frost FormationTBMG-368585/1/2020
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.
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
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
Kolbakir, Cem, Gao, Linyue, Liu, Yang, Hu, Hui
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
Brassard, Jean-Denis, Laforte, Caroline, Tremblay, Marc Mario, Volat, Christophe
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
Yavas, Denizhan, Bastawros, Ashraf, Dawood, Bishoy, Giuffre, Christopher
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
Gao, Linyue, Veerakumar, Ramsankar, 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
Bucknell, Alexander, McGilvray, Matthew, Gillespie, David, Jones, Geoffrey, Collier, Benjamin
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
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
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
Xuan, Tang, Wei, Xuezhe, Dai, Haifeng, Venturi, Massimo
A Progress Review on Gas Purge for Enhancing Cold Start Performance in PEM Fuel Cell2018-01-13124/3/2018
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
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
Marchetti, Mario, Casteran, Guillaume, Jobard, Celine, Saintot, Bruno, Bourson, Patrice, Fontana, Marc
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
Sambandan, Saravanan, Valencia, Manuel, S, Sathish Kumar
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
Smart, Michael, Vaishnav, Satish, Waslander, Steven
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
Nagano, Hideaki, Tomita, Kenji, Tanoue, Yasuhiro, Kobayashi, Yuji, Kohri, Itsuhei, Kato, Shinsuke
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
Badshah, Huzeifa, Kittelson, David, Northrop, William
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
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
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
Sivakumar, Anandan, Saishanker, V., Gopal, Raghvendra
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
Arnault, Nicolas, Monsallier, Guy
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
Kalligeros, Stamatios Spyridon, Zannikos, Fanourios, Lois, Evripidis, Anastopoulos, George
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
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
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
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
Kim, Sung-Jun, Hyun, Soungjae, Park, JaeIn
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
Laurikko, Juhani, Nylund, Nils Olof, Aakko-Saksa, Paivi
Icing Process of Supercooled-Water Droplet Moving on a Surface by Using Luminescent Temperature-Imaging Technique2013-01-22109/17/2013
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
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
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
Mikkonen, Seppo, Kiiski, Ulla, Saikkonen, Pirjo, Sorvari, Jari
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