Browse Topic: Humidity

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System Level Temperature Distribution and Balancing in battery swapping stations2026-26-03611/16/2026
Battery charging systems generate heat during operation, which affects battery efficiency, discharge time, and overall lifespan. Effective thermal management is essential to prevent overheating, optimize heat dissipation, and ensure consistent performance. This study investigates testing methodologies to analyse thermal temperature distribution, detect imbalances, and implement effective balancings techniques. Testing was conducted in a controlled environmental chamber to evaluate heat dissipation behavior under varying conditions. Different dock-level temperatures were measured and optimized using multiple design configurations to assess their impact on thermal performance. The analysis identified thermal imbalances that contribute to uneven heat distribution and increased thermal stress, which can degrade battery performance over time. By refining system designs and incorporating optimized balancing strategies, the research demonstrated significant improvements in heat management
Kulkarni, Mukund, P, Hari Prasad Reddy, H, Manjunatha, Dash, Soumya
Enhancing Thermal Comfort and Vehicle Energy Efficiency: A Simulation Study Using GT ISE + TAITherm2026-26-04581/16/2026
The automotive industry is encountering difficulties in balancing occupant thermal comfort with HVAC system energy efficiency, particularly under the hot Indian conditions, to meet user expectations and address range anxiety in electric vehicles. Front-loaded comfort-based approach simulations during the development stages have the potential to increase energy savings compared to the stages required at the end of product design. The focus of the current research targets HVAC energy consumers, such as blower flow rates, temperatures, and Cabin heaters, and investigates how these factors influence occupant overall comfort. Additionally, design elements like glass properties and the impact of solar radiation on human comfort are studied at the early concept stages to adopt an energy-based approach for comfort optimization. Simulations are conducted using GT-SUITE and GT-TAITherm software, integrated with CFD field maps platforms to obtain exact flow field predictions. The simulation
BAVIRISETTI, SAI SAMPATH KUMAR, Chothave, Abhijeet, Gummadi, Gopakishore, Khan, Parvej, Thiyagarajan, Rajesh
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
Sinopoli, David, miranda dias, PATRICIA, DEVILLIERS, GEORGES
Design methodology for avoiding condensation in automotive head lamps2024-26-00831/16/2024
One of the important aspect to consider at the design stage is the condensation of water vapor inside the lighting system, under particular weather conditions of temperature and humidity, which may compromise the device functionality. Condensation of water vapor is an issue affecting functional and aesthetics of Head Lamp. The current paper analyses the process of water vapor condensation inside an automotive LED head lamp. This paper also discusses the design methodology to avoid condensation under particular conditions. Design methodology includes design considerations for better air movement for heat management, material selection, ease of moisture exchange, breather or vent selection, placement. Additionally, this paper would also discuss about effective use of simulations tools, test methods and assembly process guidelines to avoid impact due to condensation. This paper would consist of one example with application of above methodology, its test and field results.
RANE, SANDEEP BALU, Pawar, Nishant
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
Simulation Of Air Conditioning System For Thermal Comfort Using Machine Learning techniques2022-26-12295/26/2022
This study is about the system which establishes a model for environmental factors such as temperature, humidity, and air velocity of thermal comfort indicators by implementing different Machine Learning technique. In this work the principal goal is analyzing air flow, distribution of temperature and pressure in the Living room. In order to achieve the goal the domain is consider which is divided in to discretized manner which will be further used to record the thermal sensation and airflow. For the same simulated environment the experiment will be conducted, which resulting in to forming the dataset with respect time, relative humidity, draft, temperature, air flow. By considering the recorded dataset, machine learning algorithm like SVM (Support Vector Machine), radial basis function for different kernels, Decision tree, XG Boost and Adaboost are used to create the model in Pythan. Finally, various performance metrics like accuracy, sensitivity and specificity for all techniques are
Shete, Prachi, raut, vaishnavi, Mandhare, Janhavi, Borgaonkar, Apeksha, Dorwat, Ajit
Evaluation of the Effect of Ambient Conditions on the Fuel Consumption of Commercial Vehicles2022-01-06423/29/2022
The goal of this study was to evaluate the effect of environmental conditions, and particular of ambient temperature, on fuel efficiency. Data from various and extensive operational testing were analyzed, such as tests conducted with four groups of medium and heavy-duty vehicles, involved in regional transport, local transport, pick-up and delivery, and urban transport (school bus). The tests were conducted over 5 months of warm season followed by four months of cold season. Other operational testing was conducted over one year in two different geographic and climatic regions in Canada. Data from extensive track testing conducted based on the SAE J 1321 Fuel Consumption Test Procedure-Type II, with various vehicles in different test condition, from spring to winter, was also analyzed. In this type of tests, a control vehicle is used for the base trial, as well as the final trial. As there is no change on the control vehicle, only the environmental conditions impact the fuel consumption
Surcel, Marius-Dorin
Measurement of Particle Dynamics on the Real Vehicle in Different Driving Scenarios with Swarm Sensors2021-01-129910/11/2021
Due to the increase in public attention in the analysis of non-exhaust emission sources because of the growing electrification of vehicles, measurements have been performed in recent years to develop a consistent test standard. In particular, the consideration of tyre and brake abrasion took a predominant position due to the small particle sizes. With measurements under controlled and laboratory-like athmosphere, for example for brakes on dynamometers, attempts have been made to create a uniform test standard according to the Worldwide harmonized Light vehicles Test Procedure (WLTP). However, a transfer to the real driving environment is not yet feasible because of many external disturbance variables, such as the wheel housing or atmospheric variables. Typical reference measurement sensors in the vehicle are only suitable to a limited extent for mobile operation due to their size and the necessary measurement infrastructure. The aim of this work is to analyse swarm measurements on a
Ostermeyer, Georg-Peter, Lehne-Wandrey, Guido, Sandgaard, Malte
Investigating Humidity Effects on SI Small Offroad Engine Performance and Emissions2021-01-12249/21/2021
Collaborative research outlined in this paper documents recent engine and emission performance of a newer, more robust small SI engine across a sweeping range of relative humidity having fixed intake air temperature and pressure. The experimental results will show that power correction references to SAE J1349 as well as humidity correction reference for Kh in EPA 40 CFR 1065 may generically be applied, but do not accurately compensate for the extent of correction required. The test results shared from this particular performance testing of a Kohler KT745 carbureted engine develops the case for a more diverse and less conservative approach to a one-size-fits all strategy related to humidity corrections within the small SI testing community. Moreover, humidity effects for both observed and corrected power, as well as emission corrected constituents (not just NOx) are generally greater than would otherwise be assumed from the literature. From these results, the authors will show that
Olmos Jr, Adrian, Griffin, Steven, Price, Gary, Beilke, Nathan, Sajdowitz, Scott
Automotive Buzz, Squeak and Rattle Attenuation Technique from Front Suspension Assembly in Passenger Car2021-01-10878/31/2021
BSR noise is an important parameters for customer discomfort. According to a market survey, squeaks and rattles are the third most important customer concern in cars after six months of ownership. The high quality acoustic environment of a car, annoying noises like buzz, squeak, and rattle is related to various parameters such as material assembly, tolerance, aging, humidity, surface contact, and surface hardness. BSR is originated from frictional movement between two parts or from the impact between two parts. The rattle noise is caused when surfaces close to each other move perpendicular to each other due to insufficient attachments or insufficient structural strength. In our study, we have shown the impact of various front suspension component in front suspension assembly on BSR noise and also the method to detect and attenuate the same. A methodical analysis process is shown to identify the contributing part and resolve the BSR issue. A detailed case study on vehicle level is
Deshmukh, Sagar, Hazra, Sandip, Mohare, Gourishkumar
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
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
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
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
Maximum-Allowable-Airspeed Instruments (Turbine Powered Subsonic Aircraft)AS437B-TEST-REC (Historical)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
Continuous and Stable Lasing Achieved From Low-Cost Perovskites at Room TemperatureTBMG-3801111/1/2020
An international team of researchers led by Kyushu University and Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, has demonstrated stable, continuous lasing at room temperature for over an hour from a class of low-cost materials called perovskites by finally overcoming a phenomenon that has so far prevented such long operation.
Further Development of Particulate Sensors for Mobile Use with the Aid of a Circuit Board2020-01-163810/5/2020
In the last decade, pollution by particulate matter and its effect on human health has increasingly becoming the focus of public attention. In order to monitor and evaluate particulate pollution, expensive measuring stations were placed at traffic hotspots and other selected locations. The measuring devices often precisely record the particle concentration, but have disadvantages in mobility and for measurements in large-area due to their size and investment costs. A measurement with high temporal and spatial resolution is not possible with these stations. This paper presents a new type of mobile particulate sensor based on the Plantower PMS 7003 particle sensor. In addition to the Plantower sensor, a rechargeable battery and newly developed control electronics are also installed in the particulate sensor. Due to the small size and the low manufacturing costs of the measuring system, mobile usage in higher quantity is possible. In addition, the system can record the geographical
Sandgaard, Malte, Lehne-Wandrey, Guido, Otto, Johannes, Ostermeyer, Georg-Peter
Comparison of Particulate Matter and Number Emissions from a Floating and a Fixed Caliper Brake System of the Same Lining Formulation2020-01-163310/5/2020
The particulate emissions of two brake systems were characterized in a dilution tunnel optimized for PM10 measurements. The larger of them employed a fixed caliper (FXC) and the smaller one a floating caliper (FLC). Both used ECE brake pads of the same lining formulation. Measured properties included gravimetric PM2.5 and PM10, Particle Number (PN) concentrations of both untreated and thermally treated (according to exhaust PN regulation) particles using Condensation Particle Counters (CPCs) having 23 and 10 nm cut-off sizes, and an Optical Particle Sizer (OPS). The brakes were tested over a section (trip-10) novel test cycle developed from the database of the Worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). A series of trip-10 tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. Selected tests were also performed over a short version of the Los Angeles City Cycle. PM2.5 emissions of burnished pads
Mamakos, Athanasios, Arndt, Michael, Hesse, David, Hamatschek, Christopher, Augsburg, Klaus
Augmentation of Energy, Exergy and Emission Performance of Gas Turbine Engines Used for Ship Propulsion2020-01-20289/15/2020
Majority of prime movers for ship propulsion used currently are diesel engines mainly because of their elevated efficiency and their ability to run on residual oil. But in view of the increasing awareness for pollution control and stricter environmental regulations, gas turbine cycle can be regarded as a suitable alternative to propel large ships for cargo and military purpose. However during summer and in hot and humid climates, an increase in ambient temperature and ambient relative humidity is observed to adversely affect the performance of gas turbine (GT). In such circumstances, integration of inlet air cooling to GT cycle can be considered as a suitable alternative. The present paper discusses the possibility of using a vapor absorption inlet air cooled gas turbine cycle as a prime mover for marine application. A parametric study of the effect of compressor pressure ratio, turbine inlet temperature, ambient relative humidity and ambient temperature on energy, exergy and exhaust
Mohapatra, Alok Kumar, Panigrahi, Nabnit, Das, Amar Kumar
Smart Windows Self-Illuminate on Rainy DaysTBMG-376609/1/2020
Smart windows that automatically change colors depending on the intensity of sunlight are gaining attention as they can reduce energy bills by blocking the sun's visible rays during summer. But what about windows that change colors depending on the humidity outside during the monsoon season or on hot days of summer? Recently, a Korean research team has developed the source technology for smart windows that change colors according to the amount of moisture, without needing electricity. The team successfully developed a variable color filter using a metal-hydrogel-metal resonator structure using chitosan-based hydrogel and combined it with solar cells to make a self-powering humidity sensor.
Cellulose-Based Sensor Simultaneously Measures Pressure, Temperature, and HumidityTBMG-374818/1/2020
Researchers have developed a single sensor that combines the ability to measure pressure, temperature, and humidity simultaneously. The sensor has applications such as monitoring patients at home, robotics, electronic skin, functional textiles, surveillance, and security.
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
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
A detailed study of prominent factors affecting evaporator frosting in a mobile air conditioning (MAC) system2020-28-00144/30/2020
In an automotive air conditioning system, evaporator is well designed for effective heat transfer between refrigerant and air flowing over the evaporator. Hence, the better cooling and dehumidifying the incoming air. Sometimes, at the low ambient temperature and higher relative humidity conditions a frost is observed. It is accumulated over the evaporator and often become thicker enough to block the flow of air completely passing through the evaporator resulting in a rise in vehicle cabin temperature. Current work presents the probable causes of frost formation and their effects on the performance of evaporator and hence, the performance of the automotive air conditioning system. There are four major factors, thermistor poor response, undercharged and overcharged system, clogged air-filter, and also the type of compressor causing frost formation over the evaporator are considered for analysis. Current work presents the experimental analysis of the evaporator performance in the low
Nagarhalli, Prasanna V, Maurya, Anurag, Awate, Shrikant M, Syed, Mubeen, Nagarhalli, Prasanna V, Maurya, Anurag, Awate, Shrikant M, Syed, Mubeen
Sensitivity Analysis of Aerodynamic Drag Coefficient to EPA Coastdown Ambient Condition Variation2020-01-06664/14/2020
The test cycle average drag coefficient is examined for the variation of allowable EPA coastdown ambient conditions. Coastdown tests are ideally performed with zero wind and at SAE standard conditions. However, often there is some variability in actual ambient weather conditions during testing, and the range of acceptable conditions is further examined in detail as it pertains to the effect on aerodynamic drag derived from the coastdown data. In order to “box” the conditions acceptable during a coastdown test, a sensitivity analysis was performed for wind averaged drag ((CDW ) ̅) as well as test cycle averaged drag coefficients (CDWC) for the fuel economy test cycles. Test cycle average drag for average wind speeds up to 16 km/h and temperatures ranging from 5C to 35C, along with variation of barometric pressure and relative humidity are calculated. The significant effect of ambient cross winds on coastdown determined drag coefficient is demonstrated.
Lounsberry, Todd, Tripp, John, Fadler, Gregory
Investigation of the operating conditions on the water and thermal management for a polymer electrolyte membrane fuel cell by one-dimensional model2020-01-08564/14/2020
Water and thermal management is an essential issue that influences performance and durability of a polymer electrolyte membrane fuel cell (PEMFC). Water content in membrane decides its ionic conductivity and membrane swelling favors the ionic conductivity, resulting in decreases in the membrane’s ohmic resistance and improvement in the output voltage. However, if excessive liquid water can’t be removed out of cell quickly, it will fill in the pores of catalyst layer (CL) and gas diffusion layer (GDL) then flooding may occur. It is essential to keep the water content in membrane at a proper level. In this work, a transient isothermal one-dimensional model is developed to investigate effects of the relative humidity of inlet gas and cell temperature on performance of a PEMFC. Comprehensive physical and chemical phenomenon inside the cell is included, especially the mass transfer of hydrogen, oxygen, vapor and liquid water in gas channels, GDL and CL and non-frozen membrane water in
Wang, Xuhui, Dong, Yaqian, Xu, Sichuan
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
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.
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.
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
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
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
Numerical Simulation of Ice Crystal Accretion Inside an Engine Core Stator2019-01-20176/10/2019
A CFD simulation methodology is presented to calculate blockage due to ice crystal icing of the IGV passages of a gas turbine engine. The computational domain consists of six components and includes the nacelle, the full bypass and the air induction section up to the second stage of the low-pressure compressor. The model is of a geared turbofan with a fan that rotates at 4,100 rpm and a low-pressure stage that rotates at 8,000 rpm. The flight conditions are based on a cruising speed of Mach 0.67 in Appendix-D icing conditions with an ice crystal content is 4.24 g/m3. Crystal bouncing, and re-entrainment is considered in the calculations, along with variable relative humidity and crystal melting due to warmer temperatures within the engine core. Total time of icing is set to 20 seconds. The CFD airflow and ice crystal simulations are performed on the full 6-stage domain. The initial icing calculation determines which stage will be chosen for a more comprehensive analysis. In this case
Nilamdeen, Shezad, Rao, Vinod Singh, Switchenko, David, Selvanayagam, Jeyatharsan, Ozcer, Isik, Baruzzi, Guido S.
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
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
Agui, Juan H., Struk, Peter, Bartkus, Tadas
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
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
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
Zhang, Yue, Ozcer, Isik, Nilamdeen, Shezad, Baruzzi, Guido S., Selvanayagam, Jeyatharsan
Effect of Icing Environment and Humidity on Reference Air Data Parameters in an Icing Tunnel2019-01-19296/10/2019
Wind tunnel facilities typically rely upon reference instrumentation combined with isentropic flow relationships to define the fluid properties in the test section. For the particular case of icing wind tunnels, the icing environment can affect the airflow such that the definition of test section parameters via isentropic relationships is not strictly correct. These influences are of particular importance for testing air data probes because the nature of the test is to evaluate the performance of a sensor directly measuring the parameters being affected. Momentum, heat, and mass transfer from the water phase to the air phase can result in total temperature and total pressure measurements in the test section that differ from those measured at an upstream station, where reference measurements are typically taken. This effect was first observed by Luers & Fiscus [1] in the context of wind tunnel tests for heavy rain conditions.
Whalen, Mac, Matheis, Brian
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
Influence of Secondary Flow Generation on Heat Transfer inside the Fin Type Spiral Sub-Cooled Condenser by Experimental and CFD Analysis2018-32-005410/30/2018
This paper discusses the compact structure, innovative and unique approach of high performance spiral coil sub-cooled condenser for compact power plant/engine applications. The motivation behind this study is to reduce the engine emission by improving the coefficient of performance for air-conditioning unit. Since the air conditioning system is the most power consumption units after the power plant, so it significantly affects the fuel consumption and the hazardous gas emissions. In the air condition cycle, the condenser unit is addressed as one of the important devices, and thus, the author tried to reduce the energy consumption by improving the performance of the condenser. The most advantage points of this study is to use spiral coil sub-cooled condenser, which elaborates the effect of secondary flow generation inside the fluid and is known as the Dean’s effect. This results in the heterogeneous temperature distribution across the periphery of the tube and lead to a greater heat
Singh, Hardeep, Suzuki, Takashi, Washiashi, Junya, Ichiyanagi, Mitsuhisa, Liu, Jun
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
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
Zhao, Changpu, Wang, Ke, Huang, Sirui
Thermodynamic Analysis of an Evaporative Inlet Air Cooled Combined Cycle for Marine Application2018-01-17779/10/2018
The integration of inlet air cooling to gas turbine based power utilities is a well accepted practice as this modification to the utility delivers superior utility performance. However, application of inlet-air cooling to drive turbines and specifically to marine mobility sector is rare in literature. Marine vessels are generally propelled by diesel engines, however large marine vessels specifically cruise ships and high speed naval vessels may have requirements of higher speeds and on-board power requirements which can fulfilled by gas turbine driving the propellers while on-board power needs can be met by steam turbine power generated from gas turbine exhaust heat. Such gas-steam combined cycles have the potential to become popular for high capacity marine vessels. The choice of gas turbine based combined cycle power plant for marine vessels in comparison to diesel engine powered vessel is also superior due to lower emission from the former. Higher ambient temperatures are known to
Mohapatra, Alok Kumar, S, Sanjay, Choudhary, Tushar, Kumari, Anupam, S, IRSHAD
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
Japins, Guntis, Kalnins, Kaspars, Kirpluks, Mikelis, Cabulis, Ugis
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