Browse Topic: Humidity

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Cloths, Cleaning, For Aircraft Primary and Secondary Structural SurfacesAMS3819E (Current)12/9/2025
This specification covers woven, nonwoven, and knit absorbent materials supplied either as dry cloths or presaturated cloths for solvent cleaning process applications.
AMS G9 Aerospace Sealing Committee
Corrosion Prediction for Helicopter Application for MaintenanceF-0080-2024-12735/7/2024
Corrosion occurs in diverse environments mainly on metallic parts. Helicopters are made of a huge percentage of metallic parts and need to have several maintenance steps to guarantee its functioning and its durability. The military helicopters are flying in different kinds of environment, which cover large spectrum of severity of the atmospheric corrosion [1]. In maritime conditions, the most influencing factor is the Time of Wetness, which is a direct result Relative Humidity and Salt loading. The main material used for aircraft and that is suffering from corrosion is aluminium. There are plenty of data to follow the corrosion as a function of the environmental conditions, mainly on the sensitivity with sodium chloride, Relative Humidity, film thickness, etc... [2][3]. The maintenance efficiency on helicopters is dependent on the environmental severity. The U.S. armed forces estimate $10.2 billion in corrosion costs for their aviation and missile fleets during 2016 [4] [5] [6]. The aim of the present analysis consists of defining the Condition Based Maintenance related to corrosion risk to better apply a maintenance program when it is really needed.
Sinopoli, David, miranda dias, PATRICIA, DEVILLIERS, GEORGES
Influence of Temperature and Humidity on Flax Fiber-Reinforced Composites for Helicopter Structures Using Protective CoatingsF-0079-2023-181675/16/2023
ABSTRACT
Gaugelhofer, Lukas, John, Jonas, Hajek, Manfred, Yavrucuk, Ilkay
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
Induction Cure Test for Metal Bonding AdhesivesJ1851_202101 (Current)1/7/2021
This SAE Recommended Practice defines a procedure for determining the adhesion strength characteristics of heat-cured metal bonding adhesives subjected to induction heating.
Materials, Processes and Parts Council
Abrasion Resistance Testing - Vehicle Exterior Graphics and Pin StripingJ1847_202101 (Current)1/7/2021
This SAE Recommended Practice applies to the abrasion resistance testing of decorative tapes, graphics, and pin striping. It may also have relevance to certain vehicle labels and plastic wood grain film. The resistance to abrasive damage is judged qualitatively by its effect on the legibility, pattern, and color of the graphic marking. This recommended practice is intended as a guide toward standard practice but may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering the use of this recommended practice.
Materials, Processes and Parts Council
Peel Adhesion Test for Glass to Elastomeric Material for Automotive Glass EncapsulationJ1907_202101 (Current)1/7/2021
This recommended practice defines a procedure for the construction and testing of a 180 deg peel specimen for the purpose of determining the bondability of glass to elastomeric material in automotive modular glass. This test method suggests that elastomeric material of less than 172 mpa modulus be used as the encapsulating material. The present practice of encapsulating automotive glass is described as molded-in-place elastomeric material onto the outer edge of the glass using thermoplastic or thermosetting material that quickly sets in the mold. The glass is removed from the mold with the cured elastomeric material bonded to the perimeter of the glass. This encapsulated glass module can now be bonded with a sealant adhesive into the body opening of a vehicle.
Materials, Processes and Parts Council
Maximum-Allowable-Airspeed Instruments (Turbine Powered Subsonic Aircraft)AS437B (Current)12/22/2020
This SAE Aerospace Standard (AS) covers one type of maximum-allowable-airspeed instrument which gives a continuous indication of both indicated airspeed and maximum allowable airspeed not exceeding 650 knots.
A-4 Aircraft Instruments Committee
Low-Duty Inertia Dynamometer Hydraulic Brake Wear Test Procedures for Vehicles Above 4536 kg (10000 pounds) of GVWRJ3006_202005 (Current)5/26/2020
This Recommended Practice is derived from OEM and tier-1 laboratory tests and applies to two-axle multipurpose passenger vehicles, or trucks with a GVWR above 4536 kg (10 000 pounds) equipped with hydraulic disc or drum service brakes. Before conducting testing for a specific brake sizes or under specific test conditions, review, agree upon, and document with the test requestor any deviations from the test procedure. Also, the applicable criteria for the final test results and wear rates deemed as significantly different require definition, assessment, and proper documentation; especially as this will determine whether or not Method B testing is needed. This Recommended Practice does not evaluate or quantify other brake system characteristics such as performance, noise, judder, ABS performance, or braking under extreme temperatures or speeds. Minimum performance requirements are not part of this recommended practice. Consistency and margin of pass/fail of the minimum requirements related to wear rates and wear behavior can be assessed as part of the project in coordination with the test requestor. NOTE: This Recommended Practice uses the unit conversion and rounding techniques from the NIST Special Publication 811. This to ensure the use of standard conversion factors and to determine the appropriate number of significant digits to ensure the Rounding Error (RE) of the converted unit is smaller than or similar to the RE of the original English or Imperial unit.
Truck and Bus Hydraulic Brake Committee
Plain Bearing No-Load Rotational Breakaway Torque MeasurementARP5448/5B (Current)5/26/2020
This test method provides a procedure for measuring no-load rotational breakaway torque of self-lubricating spherical bearings.
ACBG Plain Bearing Committee
Fluoride Offgassing in Fluoropolymer InsulationsARP6229 (Current)3/24/2020
This SAE Aerospace Recommended Practice (ARP) shall be limited to information about corrosion caused by fluoride offgassing of fluoropolymer-based wire insulation. It reviews published reports of corrosion caused by this phenomenon, describes scenarios where this may be a concern, mitigation options, and references a test method which can be used to evaluate wire insulations where needed.
AE-8D Wire and Cable Committee
O-Ring Machined from AMS3617 MaterialAS9772A (Current)1/13/2020
This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings machined from AMS3617 polyamide material. It shall be used for procurement purposes.
A-6C2 Seals Committee
Smart, Hybrid Actuators Combine Nanometer Precision, Large Forces, and Long Travel Ranges with High DynamicsTBMG-3529010/1/2019
The characteristics of hybrid drives present a practical solution when a position needs to be detected with high precision and moved repeatedly over long travel ranges, or when a target position needs to be reached with nanometer precision. Application areas include precision movement of telescopes, microscopy, surface inspection, semiconductor manufacturing, and laser technology.
High-Volume Electrospinning Production Platform for Medical DevicesTBMG-3537110/1/2019
A newly developed platform has been designed for large-scale industrial manufacturing of reproducible and scalable fiber-based scaffolds for Class I, II and III medical devices. The launch of the MediSpin XL™ platform marks a global breakthrough in the controlled large-scale production of well-defined scaffolds for implants and membranes using fibers ranging from nanometer up to micrometer scale.
Analysis of a Coupling System of Aircraft Environmental Control and Fuel Tank Inerting Based on Membrane Separation2019-01-18959/16/2019
This paper raises a coupling system of aircraft environmental control and fuel tank inerting based on membrane separation. The system applies a membrane dehumidifier to replace water vapor removal unit of heat regenerator, condenser and water separator, which is widely used in conventional aircraft environmental control system (ECS) nowadays. Water vapor can travel across the membrane wall under its pressure difference without phase change, so the dehumidification process consumes no cooling capacity as traditional ECS and the cooling capacity of the new system increases. This paper first compares the thermodynamic properties of ECS based on membrane dehumidification and the traditional ECS based on condensation. The results show that the membrane dehumidification system has larger cooling capacity and lighter weight. For a given cooling capacity requirement, the membrane dehumidification system can use less bleed air since the enthalpy of the outlet air is lower. Besides, the fuel tank inerting system also uses an air separation module to produce nitrogen enriched air based on membrane separation. After the air is dehumidified in membrane dehumidification ECS, its parameters meet the requirement of membrane air separation module. Thus, it is reasonable to combine the two systems together. This paper conducts a simulation analysis of the coupling system. Comparing with the conventional four wheel high pressure de-water ECS and fuel tank inerting system used onboard nowadays, the coupling system has simpler structure and lighter weight. The simulation results show that the coupling system can decrease the fuel penalty by 139.67kg each pack.
Yuan, Weixing, Zheng, Yan, Hou, Jiaqi
Real Driving Emissions Measurement of Brake Dust Particles2019-01-21389/15/2019
The measurement of brake dust particles is a complex challenge owing to its open system configuration; indeed, the emitted particles are directly spread into the environment. Measurements on the inertia brake dyno feature controllable and reproducible environmental and operational parameters. Although Real Driving Emission (RDE) measurements enable the detection of brake dust particles emitted in real driving conditions (i.e. traffic condition, driving style, air humidity, vehicle components’ wear and ageing, etc.), they are complex and not reproducible due to external, continuously changing parameters (e.g., flow conditions, changing traffic conditions, particulate matter from other sources). The motivation lies in developing a real driving emission sampling system for brake particle emissions, which meets the quality requirements of the measurements, as well as the prevention of particle losses and contamination, thereby supplementing and reviewing laboratory-based procedures. On the basis of knowledge from the computational fluid dynamics and experimental investigations, an advantageous concept of a sampling system for mobile application is presented. The chosen methodological approach shows that the transport efficiency and the uniformity of the number concentration depend on the design, the associated flow conditions and process parameters. In addition, the Particle injection and particle spreading behaviour, influence of disc ventilation and the variable particle properties over the cycle are to be implemented into the evaluation. As a result, an optimized design of a sampling system for mobile applications is derived. Furthermore, the results express the influence of different test environments, test cycles and test setups. The experimental study shows fundamental differences and similarities between laboratory and real-road test environments.
Hesse, David, Augsburg, Klaus
Flammability of Polymeric Interior Materials - Horizontal Test MethodJ369_201908 (Current)8/8/2019
This SAE Standard pertains to automotive vehicles and off-road, self-propelled work machines used in construction, general purpose industrial, agriculture, forestry, and specialized mining machinery. This standard does not address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this document to establish safety and health practices and determine the applicability of regulatory limitations prior to use. Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed when conducting this test.
Textile and Flexible Plastics Committee
Moisture Sensor Based on NASA Humidity SensorTBMG-349068/1/2019
Roscid Technologies Woburn, MA
Photogrammetric Frost Roughness Measurements in Cold-Soaked Conditions2019-01-19706/10/2019
Cold-soaked fuel frost (CSFF) is a form of aircraft wing contamination that occurs when a vehicle caries sufficient fuel for multiple trips or take-offs and landings. Following the first trip, which may reach altitudes above 10,000 m (33,000 ft), the fuel for the subsequent trips is carried in the wing tanks and may reach temperatures below -25 °C. In certain times of the year at some airports, temperatures and humidity levels will form CSFF on the aircraft wing surfaces over the fuel tanks. Unless an exemption is granted for the specific aircraft model, aircraft are not allowed to takeoff if the wing surfaces are contaminated by frost. Because aircraft operators desire to minimize vehicle time spent at airports, aircraft manufacturers are expected to pursue designs that safely operate with CSFF at takeoff and to pursue certification exemptions for aircraft models enabling CSFF takeoffs. To assist manufacturers in the design of future aircraft and to assist regulators in evaluating certification exemption requests, more information about frost roughness characteristics and evolution in CSFF conditions is required. However, because of the material and optical properties of frost, measuring CSFF properties using traditional roughness measurement presents challenges. For this investigation, a photogrammetric approach based on “structure-from-motion” algorithms traditionally employed in aerial surveying was developed to characterize the evolution of CSFF roughness. Using the approach, measurements of frost roughness evolution were performed in the Baylor Frost Tunnel (BFT) for two basic air temperature, humidity, surface temperature, and velocity conditions with frost time up to two hours. An analysis of variance approach was used to determine the sensitivity frost growth rates to the environmental conditions. The resulting measurements demonstrate different evolution histories with air velocity and air temperature being the most important factors governing roughness growth.
Miyauchi, Taber, McClain, Stephen T., Zhang, Tongxin, O'Neal, Dennis L., Riley, James T.
Experimental Investigation of High Speed SLD Impact2019-01-20066/10/2019
This paper proposes an experimental investigation of fast impinging large droplets in non-icing conditions. Two main aspects of the impact event are analyzed and discussed: the impact dynamics as a function of the surface nature and the deposition rate of the liquid on the impingement surface for various conditions. The data has been recorded and characterized at ambient pressure and a temperature of the air between 5 and 10°C using a vertical wind/droplet tunnel. To avoid the droplets evaporation the relative humidity was controlled. The morphology of impact was studied by backlighted imagery and quantitative results were obtained by image analysis. The deposition rate was obtained weighting the water accumulated on the impingement plate. Examination of splashing events images obtained on a clean surface and on blotter paper shows important differences in terms of secondary drop generation. The measurement of the deposition rate confirmed that the dynamics of drop impingement on blotter paper is not the same as impingement on a clean surface. These differences may significantly impact the development of models for icing applications.
BODOC, Virginel, Berthoumieu, Pierre
Numerical Demonstration of the Humidity Effect in Engine Icing2019-01-20156/10/2019
The importance of the variation of relative humidity across turbomachinery engine components for in-flight icing is shown by numerical analysis. A species transport equation for vapor has been added to the existing CFD methodology for the simulation of ice growth and water flow on engine components that are subject to ice crystal icing. This entire system couples several partial differential equations that consider heat and mass transfer between droplets, crystals and air, adding the cooling of the air due to particle evaporation to the icing simulation, increasing the accuracy of the evaporative heat fluxes on wetted walls. Three validation cases are presented for the new methodology: the first one compares with the numerical results of droplets traveling inside an icing tunnel with an existing evaporation model proposed by the National Research Council of Canada (NRC). The second one compares humidity and the reduction in the outflow total temperature to the experimental data from NASA Glenn Research Center’s Propulsion Systems Laboratory (PSL). The third case shows that the vapor model improves our icing validation of the crowned cylinder case compared to the NRC experimental data. For the simulation technology demonstration, turbofan icing scenarios with inflow relative humidity varying between 30 and 100% are simulated using a generic engine intake that includes the first stages of the compressor. The inclusion of vapor transport and local relative humidity provide important additional modeling functionalities and increased simulation accuracy.
Zhang, Yue, Ozcer, Isik, Nilamdeen, Shezad, Baruzzi, Guido S., Selvanayagam, Jeyatharsan
Ice-Crystal Icing Accretion Studies at the NASA Propulsion Systems Laboratory2019-01-19216/10/2019
This paper describes an ice-crystal icing experiment conducted at the NASA Propulsion System Laboratory during June 2018. This test produced ice shape data on an airfoil for different test conditions similar to those inside the compressor region of a turbo-fan jet engine. Mixed-phase icing conditions were generated by partially freezing out a water spray using the relative humidity of flow as the primary parameter to control freeze-out. The paper presents the ice shape data and associated conditions which include pressure, velocity, temperature, humidity, total water content, melt ratio, and particle size distribution. The test featured a new instrument traversing system which allowed surveys of the flow and cloud. The purpose of this work was to provide experimental ice shape data and associated conditions to help develop and validate ice-crystal icing accretion models. The results support previous experimental observations of a minimum melt-ratio threshold for accretion to occur as well as the existence of a plateau region where the icing severity is high for a range of melt ratios. However, a maximum limit for melt ratio, which is suggested in the ice crystal icing literature, was not observed perhaps complicated by the potential for some supercooling of the water at these conditions.
Struk, Peter M., Agui, Juan, Ratvasky, Thomas, King, Michael, Bartkus, Tadas, Tsao, Jen-Ching
Total Temperature Measurements in Icing Cloud Flows Using a Rearward Facing Probe2019-01-19236/10/2019
This paper reports on temperature and humidity measurements from a series of ice-crystal icing tunnel experiments conducted in June 2018 at the Propulsion Systems Laboratory at the NASA Glenn Research Center. The tests were fundamental in nature and were aimed at investigating the icing processes on a two-dimensional NACA0012 airfoil subjected to artificially generated icing clouds. Prior to the tests on the airfoil, a suite of instruments, including total temperature and humidity probes, were used to characterize the thermodynamic flow and icing cloud conditions of the facility. Two different total temperature probes were used in these tests which included a custom designed rearward facing probe and a commercial self-heating total temperature probe. The rearward facing probe, the main total temperature probe, is being designed to reduce and mitigate the contaminating effects of icing and ingestion of ice crystals and water droplets at the probe’s inlet. The probe also serves as an air-sample inlet for a light absorption based humidity measurement. The paper includes a section which discusses total temperature and humidity measurement considerations, and another section which provides an analysis of the main probe’s performance characteristics. A computational fluid dynamic model of the flow around the probe was also conducted to gain insight into the trajectory of the flow entering the probe inlet. The experiments included a series of tests in which the relative humidity of the facility flow was swept through with increasingly larger values. The data showed that the rearward facing probe can reasonably capture the flow’s total temperature and humidity under mild to moderate icing conditions but can produce anomalous results under more intense icing conditions. The experimental data was also compared to an in-house developed thermodynamic model which takes into account the interaction of the main flow with the icing cloud. Comparison to the thermodynamic model showed that the rearward facing probe measured the predicted trends.
Agui, Juan H., Struk, Peter, Bartkus, Tadas
Compression and Recovery of Insulation PaddingsJ1352_201901 (Current)1/18/2019
This test method is applicable for determining the relative compression and recovery of fibrous insulation padding materials.
Acoustical Materials Committee
Environmental Degradation of Composite MaterialsARP6287 (Current)10/18/2018
In accordance with § 4.11 of AS36100, materials used in the construction of pallets, nets, and containers shall take into account the effects of environmental conditions, such as temperature, humidity, and UV degradation, expected in service. In accordance with (E)TSO-C90, the applicant shall consider environmental degradation due to aging, ultra-violet (UV) exposure, weathering, etc., for any materials used in the construction of pallets, nets, and containers. The purpose of this Aerospace Recommended Practice (ARP) is to provide guidelines for the basic requirements to be considered regarding environmental degradation effects when qualifying composite materials in the design to fulfill the (E)TSO-C90 Minimum Performance Standard. Material qualification is the verifying of a materials attributes and characterizations, which are typically determined through testing. Material variances related to raw materials and manufacturing processes are not part of this Aerospace Recommended Practice (ARP), nor is damage tolerance. However, these variances cannot be neglected, as all variances shall be considered when deciding the test factors for environmental effects.
AGE-2 Air Cargo
Numerical Investigation on Effects of Oxygen-Enriched Air and Intake Air Humidification on Combustion and Emission Characteristics of Marine Diesel Engine2018-01-17889/10/2018
In order to meet the increasingly stringent emissions restriction, it is indispensable to improve the combustion and emissions technology of high-speed marine diesel engines. Oxygen-enriched combustion and intake air humidification are effective ways to control pollution from diesel engines and improve combustion of diesel engines. In this study, the combustion and emission characteristics of supercharged intercooled marine diesel engine with humidity ratio and intake oxygen concentration were investigated by using multi-dimensional CFD model. The combustion model was established by AVL Fire code. The combination strategy of intake air humidification and oxygen-enriched combustion were optimized under partial load at 1350 rpm. The simulation results indicate that under kept the constant value of the humidity ratio, the averaged in-cylinder temperature and pressure both increase with the rise of intake oxygen concentration, while the timing of the in-cylinder peak temperature and pressure are increased, the combustion duration got short and CA50 is delayed. Meanwhile, soot emissions are inhibited while the NOx emissions increase remarkably. Intake air humidification can reduce NOx emission significantly, whereas it has little effect on soot emissions and indicated power. With humidity ratio growing, both in-cylinder combustion pressure and temperature decrease as well as NOx emissions. However, the ignition delay increased dramatically. The results reveal that the humidity ratios from 60% to 80% and the oxygen concentration from 22% to 23% can be matched to realize lower Soot-NOx emissions than the original engine with loss of the indicated power no more than 3%.
Zhao, Changpu, Wang, Ke, Huang, Sirui
Method Converts Cotton Fabric Waste into AerogelTBMG-290206/1/2018
Aerogels are among the lightest materials in the world, and are highly porous with strong absorption capacity and low thermal conductivity. These unique properties make aerogels highly suitable for applications in areas including oil spill cleaning, personal care products such as diapers, and for heat and sound insulation.
Modeling the Effect of Foam Density and Strain Rate on the Compressive Response of Polyurethane Foams05-11-02-00145/8/2018
Due to the high deformability and energy dissipation capacity of polymer foams in compression, they are used in automotive applications to mitigate mechanical impacts. The mechanical response of the foams is strongly affected by their density. Phenomenological relations have been proposed to describe the effect of foam density on their stress-strain response in compression at a fixed loading rate and the effect of loading rate at a fixed foam density. In the present work, these empirical approaches are combined allowing for the dependence of loading rate effect in compression on foam density. The minimum experimental data set for calibration of the proposed model consists of compression test results at two different loading rates of foams with two different densities. Rigid closed-cell polyurethane foams with apparent density in the range of ca. 100 to 300 kg/m3 have been produced and tested in compression up to a ca. 80% engineering strain at low (0.00167 to 0.5 s−1) and intermediate (~102 s−1) strain rates. The model parameters were evaluated from test results of the largest and smallest-density foams at low loading rates, differing by two orders of magnitude. The relative root mean square error of stress prediction for intermediate foam densities was found to range from ca. 6 to 12% at low strain rates and reach up to 34% at the higher strain rate. The proposed approach for modeling of foam behavior is expected to be useful in preliminary design of structural parts with impact mitigation functionality.
Japins, Guntis, Kalnins, Kaspars, Kirpluks, Mikelis, Cabulis, Ugis
Mobile Instrument Detects and Samples Aerosol ParticlesTBMG-288475/1/2018
Hazardous airborne particles pose a risk for health and safety in a variety of environments; thus, detection of these small particles is essential. Current particle magnification systems are bulky and require a lot of power for operation, making them unsuitable to easily detect and analyze small particles in mobile and personal settings.
Chart – Humidity Indicator, Color ComparisonAS167B (Current)4/28/2018
E-25 General Standards for Aerospace and Propulsion Systems
Implementation of Reinforcement Learning on Air Source Heat Pump Defrost Control for Full Electric Vehicles2018-01-11934/3/2018
Air source heat pumps as the heating system for full electric vehicles are drawing more and more attention in recent years. Despite the high energy efficiency, frost accumulation on the heat pump evaporator is one of the major challenges associated with air source heat pumps. The evaporator needs to be actively defrosted periodically and heat pump heating will be interrupted during defrosting process. Proper defrost control is needed to obtain high average heat pump energy efficiency. In this paper, a new method for generating air source heat pump defrost control policy using reinforcement learning is introduced. This model-free method has several advantages. It can automatically generate optimal defrost control policy instead of requiring manually determination of the control policy parameters and logics. More measurement results can be incorporated into the defrost control policy without too many changes in the reinforcement learning algorithm so that the control policy can be better optimized under wider range of working conditions. The learning features also enable the controller to adapt to the system differences and changes which are impossible to predict a priori when designing defrost control policy. The algorithm was validated using experimentally obtained heating capacity and COP data in frost growth cycle of a heat pump under different conditions. The results showed that reinforcement learning can be used to generate defrost control policy that optimizes energy consumption for various working conditions.
Zhu, Jingwei, Elbel, Stefan
Evaluating a Vehicle Climate Control System with a Passive Sensor Manikin coupled with a Thermal Comfort Model2018-01-00654/3/2018
In a previous study, a passive sensor (HVAC) manikin coupled with a human thermal model was used to predict the thermal comfort of human test participants. The manikin was positioned among the test participants while they were collectively exposed to a mild transient heat up within a thermally asymmetric chamber. Ambient conditions were measured using the HVAC manikin’s distributed sensor system, which measures air velocity, air temperature, radiant heat flux, and relative humidity. These measurements were supplied as input to a human thermal model to predict thermophysiological response and subsequently thermal sensation and comfort. The model predictions were shown to accurately reproduce the group trends and the “time to comfort” at which a transition occurred from a state of thermal discomfort to comfort. In the current study, the effectiveness of using a coupled HVAC manikin-model system to evaluate a vehicle climate control system was investigated. The test protocol prescribed a transient heat up after a cold soak of a vehicle that had been placed in a - 10 °C climate chamber. Multiple repetitions of the same scenario were run with different human subjects to reduce the influence of individual bias on the overall results and to assess the variability of test responses. The thermal sensation and comfort of the human subjects were compiled and reported in terms of average and standard deviation, which were compared to the predictions of the manikin-model system. The agreement between the manikin-model system and the human subject test results was assessed quantitatively by calculating the RMSD (root-mean-square deviation) and bias (the average error) between the predictions and the measurements.
Hepokoski, Mark, Curran, Allen, Viola, Timothy, Lindedal, Niklas, Hansson, Ronnie, Gullman, Sam
Modelling the Effect of Spray Breakup, Coalescence, and Evaporation on Vehicle Surface Contamination Dynamics2018-01-07054/3/2018
Vehicle surface contamination is an important design consideration as it affects drivers’ vision and the performance of onboard camera and sensor systems. Previous work has shown that eddy-resolving methods are able to accurately capture the flow field and particle transport, leading to good agreement for vehicle soiling with experiments. What is less clear is whether the secondary breakup, coalescence, and evaporation of liquid particles play an important role in spray dynamics. The work reported here attempts to answer this and also give an idea of the computational cost associated with these extra physics models. A quarter-scale generic Sports Utility Vehicle (SUV) model is used as a test case in which the continuous phase is solved using the Spalart-Allmaras Improved Delayed Detached Eddy Simulation (IDDES) model. The dispersed phase is computed concurrently with the continuous phase using the Lagrangian approach. The Taylor Analogy Breakup (TAB) secondary breakup and the stochastic O’Rourke coalescence models are used. The spray’s rate of evaporation is calculated based on the relative humidity encountered on a typical October day in Britain. The secondary breakup model is found to be redundant, possibly due to the properties of spray. The coalescence model predicts high coalescence of particles close to the source and improves agreement with experiment, although at a high computational cost. Including evaporation removes small particles from the simulation and reduces overall contamination. When used along the coalescence model, evaporation is found to be negligible as it does not influence large particles to the same extent as it affects small particles. This suggests that droplet physics models need to be considered together as they can have a strong effect on each other as well as vehicle soiling. Here, we show that coalescence can be accounted for by using the time-averaged spray, obtained outside the region of high coalescence. This gives a very good agreement with experiment.
Kabanovs, Anton, Garmory, Andrew, Passmore, Martin, Gaylard, Adrian
Solid-State Humidity Sensing ElementTBMG-283322/1/2018
Researchers at NASA's Marshall Space Flight Center have developed a solid-state humidity sensing element that offers ultra-high sensitivity across a wide range of humidity levels. The sensing element is based on a novel ceramic dielectric material that exhibits large changes in capacitance as a function of small changes in humidity.
Hydraulic Pressure Control and Parameter Optimization of Integrated Electro-Hydraulic Brake System2017-01-25169/17/2017
A general principle scheme of IEHB (Integrated Electro-Hydraulic Brake system) is proposed, and the working principle of the system is simply introduced in this paper. Considering the structure characteristics of the hydraulic control unit of the system, a kind of time-sharing control strategy is adopted to realize the purpose of independent and precise hydraulic pressure regulation of each wheel brake cylinder in various brake conditions of a vehicle. Because of the strong nonlinear and time varying characteristics of the dynamic brake pressure regulation processes of IEHB, its comprehensive brake performance is mainly affected by temperature, humidity, load change, the structure and control parameters of IEHB, and so on. Under certain temperature, humidity and load conditions, whether the matching of the structure and the control parameters of IEHB is appropriate or not, the brake performance of a vehicle would be affected directly and severely, and then the safe driving of a vehicle could not be guaranteed effectively. In order to enhance the adaptability of the pressure regulating performance of IEHB to external influence factors and improve the comprehensive performance index of IEHB, using the software and hardware test platform of IEHB, combining the robustness optimization design method based on the application of GA (Genetic Algorithm) and modern generalized experiments, the structure and the control parameters of IEHB are matched and optimized. Finally, by comparing the results before and after optimization, it is verified that the pressure regulation of optimized IEHB is more rapid, more accurate and more robust, the comprehensive brake performance is significantly improved, and the new type of brake system could well meet the application requirements of an advanced vehicle chassis control system in the future.
Yang, Xiong, Li, Jing, Miao, Hui, Shi, Zheng Tang
Test Method for Determining Resistance to Abrasion of Automotive Bodycloth, Vinyl, and Leather, and the Snagging of Automotive BodyclothJ948_201706 (Historical)6/7/2017
These methods of test are applicable for determining the resistance to snagging and abrasion of automotive bodycloth, vinyl, and leather.
Textile and Flexible Plastics Committee
Fluid Selection and Thermodynamic Analysis of an Electricity-Cooling Cogeneration System Based on Waste Heat Recovery from Marine Engine2017-01-01593/28/2017
The environmental issues combined with the rising of crude oil price have attracted more interest in waste heat recovery of marine engine. Currently, the thermal efficiency of marine diesels only reaches 48~51%, and the rest energy is rejected to the environment. Meanwhile, energy is required when generating electricity and cooling that are necessary for vessels. Hence, the cogeneration system is treated as the promising technology to conform the strict environment regulation while offering a high energy utilization ratio. In this paper, an electricity and cooling cogeneration system combined of Organic Rankine Cycle (ORC) and Absorption Refrigeration Cycle (ARC) is proposed to recover waste heat from marine engine. ORC is applied to recover exhaust waste heat to provide electricity while ARC is used to utilize condensation heat of ORC to produce additional cooling. Four typical high-temperature working fluids (benzene, toluene, cyclohexane and cyclopentane) are selected as ORC working fluid while ammonia/water is applied as working pair for ARC. Simulations were performed at different evaporating pressure and condensation temperature of ORC. Results show that the highest primary energy ratio of WHR system can be obtained when the condensation temperature of ORC is 135°C. Among the four fluids considered, from view of efficiency of cogeneration system, the most promising candidate are benzene and toluene. The former is suitable for high evaporation pressure system with a highest exergy efficiency of 50.8%, and the latter is potential for low evaporation pressure system with a highest exergy efficiency of 48.3%.
Liu, Peng, Shu, Ge-Qun, Tian, Hua, Wang, Xuan, Jing, Dongzhan
Coupling a Passive Sensor Manikin with a Human Thermal Comfort Model to Predict Human Perception in Transient and Asymmetric Environments2017-01-01783/28/2017
Passive sensor (HVAC) manikins have been developed to obtain high-resolution measurements of environmental conditions across a representative human body form. These manikins incorporate numerous sensors that measure air velocity, air temperature, radiant heat flux, and relative humidity. The effect of a vehicle’s climate control system on occupant comfort can be characterized from the data collected by an HVAC manikin. Equivalent homogeneous temperature (EHT) is often used as a first step in a cabin comfort analysis, particularly since it reduces a large data set to a single intuitive number. However, the applicability of the EHT for thermal comfort assessment is limited since it does not account for human homeostasis, i.e., that the human body actively counter-balances heat flow with the environment to maintain a constant core temperature. For this reason, a thermo-physiological human model is required to accurately simulate the body’s dynamic response to a changing environment. Consequently, thermo-physiological based comfort models are preferred for analyzing transient and asymmetric environments since they relate sensation and comfort to body temperatures rather than to environmental conditions. This paper demonstrates that coupling a thermal comfort model with a passive sensor manikin can accurately predict the overall comfort reported by a group of individuals. A test protocol was developed to expose a group of human subjects to mildly asymmetric radiant conditions and a slow change in ambient temperature. An HVAC manikin was positioned among the test participants. The HVAC manikin measurements were input to a human model so that thermal sensation and comfort could be predicted and compared to the values recorded by the human subjects. Model predictions were shown to accurately reproduce the group trends and the “time to comfort” at which a transition occurred from a state of discomfort to comfort.
Hepokoski, Mark, Curran, Allen, Gullman, Sam, Jacobsson, David
Analysis of the Effectiveness of Evaporator’s Hydrophilic Coating of Cores Recovered from Humid and Arid Regions2017-01-01223/28/2017
Water drainage characteristics are dependent on the design of the evaporator: specifically the design of the fins and plates along with hydrophilic coating. A part of the hydrophilic coating washes off with the moisture that condenses over the evaporator core from the air-stream. Hence, water drainage characteristics of an evaporator changes with the vehicle mileage or the age of the vehicle. Since a part of the hydrophilic coating washes away, more water is retained within the evaporator at this condition. Hence, the effectiveness of the evaporator drainage deteriorates with the age of the vehicles. At this condition, the contact angle measured at the plate increases. Author has conducted an experimental study to measure the effectiveness of hydrophilic coating from evaporators taken out from arid (9 cores) and humid areas (16 cores) as a function of vehicle mileage or vehicle age. Contact angles and water retention were measured for a number of evaporators from different OEMs. These cores are from different vehicles, with different manufacturers for the evaporators with different fin and plate design; and with different hydrophilic coatings. Experimentally measured water retention data shows that the water retention increased for the evaporators recovered from arid and humid regions by 85 gms (+27%) for arid areas; and by 110 gms (+37%) for humid area. This data is over the base case over a span of 60,000 miles. This represents a vehicle life of 5 years (Based on average 12,000 miles/year). The measured contact angles ranged from 37 to 78°. Further details are presented in the paper. This is the first paper in the open literature that deals with the vehicle mileage or vehicle age with the evaporator plate contact angle and surface coating of an evaporator.
Mathur, Gursaran D.
Test Method for Determining Resistance to Fiber Loss, Resistance to Abrasion and Bearding of Automotive Carpet MaterialsJ1530_201702 (Historical)2/13/2017
This test method covers determination of abrasion resistance, fiber loss and bearding resistance of automotive carpet materials.
Textile and Flexible Plastics Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 120, 80 (180)AMS3903/5B (Current)11/11/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 328, 175 (350)AMS3903/4B (Current)11/11/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 181, 80 (180)AMS3903/6B (Current)11/11/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 281, 80 (180)AMS3903/7B (Current)11/11/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 328, 80 (180)AMS3903/8B (Current)11/11/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 281, 175 (350)AMS3903/3B (Current)11/10/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 181, 175 (350)AMS3903/2B (Current)11/10/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Cloth, Organic Fiber, High Modulus Epoxy Resin Impregnated OC Style 120, 175 (350)AMS3903/1B (Current)11/10/2016
This specification covers one type of epoxy-resin-impregnated organic fibers in the form of woven cloth.
AMS P17 Polymer Matrix Composites Committee
Extension of Analytical Methods for Detailed Characterization of Advanced Combustion Engine Emissions2016-01-233010/17/2016
Advanced combustion strategies used to improve efficiency, emissions, and performance in internal combustion engines (IC) alter the chemical composition of engine-out emissions. The characterization of exhaust chemistry from advanced IC engines requires an analytical system capable of measuring a wide range of compounds. For many years, the widely accepted Coordinating Research Council (CRC) Auto/Oil procedure[1,2] has been used to quantify hydrocarbon compounds between C1 and C12 from dilute engine exhaust in Tedlar polyvinyl fluoride (PVF) bags. Hydrocarbons greater than C12+ present the greatest challenge for identification in diesel exhaust. Above C12, PVF bags risk losing the higher molecular weight compounds due to adsorption to the walls of the bag or by condensation of the heavier compounds. This paper describes two specialized exhaust gas sampling and analytical systems capable of analyzing the mid-range (C10 - C24) and the high range (C24+) hydrocarbon in exhaust. An automated gas chromatograph equipped with a mass spectrometer (GC-MS) sampling system was used to sample middle range hydrocarbons from raw exhaust. A separate sampling system consisting of a filter and XAD traps was used for the collection of particulate-phase and semi-volatile-phase hydrocarbons up to C24+ in dilute exhaust. After extraction, hydrocarbons trapped by the particulate filter and the XAD traps were speciated by a two dimensional gas chromatography mass spectroscopy (GCxGC-MS) technique. These two novel systems allowed more than 2000 compounds to be detected in the exhaust thus extended the analytical capacity in emission characterization.
Fanick, E. Robert, Kroll, Svitlana, Favela, Kristin
Boron Filament Tape, Epoxy-Resin-Impregnated Type B4.0-E180 (Type B0.102-E82)AMS3867/4B (Current)10/12/2016
This specification covers one type of epoxy-resin-impregnated boron filaments 0.0040 inch (0.102 mm) in diameter in the form of continuous tape supported on a glass cloth carrier.
AMS P17 Polymer Matrix Composites Committee
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