Browse Topic: Heating, ventilation, and air conditioning systems (HVAC)

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A Review of Literature on the Relationship Between Gas Turbine Engine Lubricants and Aircraft Cabin Air QualityAIR5784A (Current)11/26/2025
There has been a recent upsurge in interest from the media concerning the quality of the environment within aircraft cabins and cockpits especially in the commercial world. This has included (although by no means been limited to) the air quality, with particular reference to the alleged effects of contamination from the aircraft turbine lubricant. Possible exposure to 'organophosphates' (OPs) from the oil has raised special concerns from cabin crew. Such is the concern that government organisations around the world, including Australia, USA and UK, have set up committees to investigate the cabin air quality issue. Concern was also voiced in the aviation lubricants world at the way in which OP additives in turbine lubricants were being blamed in some reports for the symptoms being experienced by air crew and passengers. SAE Committee E-34 therefore decided that it should gather as much available information on the subject as possible. This would then enable E-34 to participate in debates on the issue and help prevent a potentially erroneous decision regarding the future of OP based additives in turbine lubricants. It would also serve as an indicator of where any additional work may be necessary to properly gauge the role that turbine lubricants, and OP additives, play in cabin air quality. This report summarises recent documentation from the literature on this subject. The contents do not necessarily represent the views of the SAE or any of the members of the study group who produced this review. The literature falls into three categories: - Air quality (Section 5), which includes: future systems to improve air quality and research plans into investigating cabin air quality - Chemistry of turbine lubricants, phosphate esters (Section 6), including evaluation of products found in cabin air and thermal breakdown products of lubricants. - Toxicity evaluation of turbine oils and additives (Section 7).
E-34 Propulsion Lubricants Committee
Low Ice Adhesion Strength Coated Rotor Blades and the Effects of Surface Temperature on Ice SheddingF-0081-2025-03105/20/2025
A study into the effects of a low ice adhesion strength coating and combined low power thermal heater system was conducted. Preliminary tests determined the mass of ice necessary to shed from the low ice adhesion strength coating at a specific ambient temperature (-4°C, -8°C, -12°C, and-16°C). The heater tests were conducted at an ambient temperature of -20°C, where the same mass of ice was accreted for each specific case temperature. With the accreted mass, the heaters were turned on until a shed event occurred. The surface temperature at the shed event was recorded. For colder temperatures such as -12°C and-16°C, the surface needed to reach a temperature within 1°C of -12°C and-16°C, respectively, to initiate a shed event. For the warmer cases the replication of ice at -20°C was not feasible, as the type of ice influences adhesion strength. Ice accreted at -20°C has different physical properties than ice formed at warm temperatures, therefore the surface temperature required for shedding did not match between the two tests. Results from the heater tests led to a discovery of a value that describes the adhesion strength normalized with respect to shed surface temperature. The value was found to be -1.09 psi/°C, averaged over six cases with varying conditions. This value is dependent upon a wide range of adhesion strength values for the system but opens possibilities of a full understanding of the hybrid thermal/passive coating system. With the experimental characterization of the adhesion strength to shed surface temperature value, future coating development could rely on heating the surface and recording the surface temperature needed for shedding. With such value, the ice adhesion strength of the coating could be characterized without the need for ice adhesion strength measurements.
Tyndall, Jack, Palacios, Jose
Augusta Regional Airport Preparation for Transformative VTOL Air Vehicle OperationsF-0081-2025-01325/20/2025
The emergence of electric Vertical Takeoff and Landing (eVTOL) air vehicles is transforming how people and freight are moved in short distances. This transformation has a profound impact on surrounding infrastructure necessary to provide Aircraft On Ground support for eVTOLs. The hover capabilities of eVTOLs have similar operating characteristics within terminal and uncontrolled airspace. However, the need to conserve battery energy via rapid approaches and departures affects terminal airspace management. To attract eVTOL operators, existing airports, landing zones, and vertiports are modifying their infrastructure to include fixed electric charging stations, additional taxiways, upgraded fire suppression systems, separate hangers, and capable MRO facilities. Augusta Regional Airport (KAGS) is the base airport for the annual Masters Golf Tournament which experiences five times the normal airport traffic and some 40,000 commuting patrons. eVTOLs can offset land traffic issues associated with commuters and supplies. Since KAGS is centroid to 32,000 square miles of territory void of major highways, basing eVTOLs can offer expedited transit services for people and goods which will have a profound impact on the economic viability and quality of life in the area.
Stanzione, Kaydon, Johnston, Diane
Basic Aircraft Oxygen Systems DesignAIR825/14 (Current)8/11/2021
This slash document collects general reference material related to gaseous oxygen system flow requirements and sizing calculations. This document will assist oxygen system equipment designers and operators to establish systems and equipment requirements. The document consists of charts, tables, system schematics, system requirements, and sample calculations for system sizing.
A-10 Aircraft Oxygen Equipment Committee
Recommended Practice for Processing and Handling Wire and Cable with Silver Plated Conductors and ShieldsARP6400 (Current)6/7/2021
This ARP specifies the recommended methods of handling silver coated conductors and shield, by the conductor fabricator, wireinsulator, distributors, harness or assembly houses, and OEM’s. Red Plague mitigation depends upon each link in the chain of supply handling the wire and cable properly.
AE-8D Wire and Cable Committee
STANDARD FOR D.C. BRUSH MOTOR - HVAC BLOWERSUSCAR6-1 (Current)11/19/2020
This standard sets forth the performance and durability requirements for 12-volt, D.C. brush-type electric motors used for automobile Heating, Ventilation, and Air Conditioning (HVAC) blowers and outlines Production Validation and Continuing Conformance testing.
USCAR
Performance Requirements for R-134a and R-1234yf Refrigerant Diagnostic Identifiers (RDI) for Use with Mobile Air Conditioning SystemsJ2912_202009 (Current)9/23/2020
Interior Climate Control Service Committee
Hose, Air Duct, Flexible, Nonmetallic, AircraftAS1501D (Current)6/10/2020
This document covers flexible and semiflexible, reinforced and unreinforced air hoses fabricated from laminated and impregnated fabric, intended for use in aircraft heating, air conditioning, ventilating, defrosting, and/or deicing systems.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Environmental Systems Schematic SymbolsARP780C (Current)5/20/2020
This SAE Aerospace Recommended Practice (ARP) provides symbols to schematically represent aerospace vehicle environmental system components on functional flow schematic drawings and graphical computerized output. The symbols are for use on simplified diagrams that provide basic information about an environmental system. Symbols are provided to represent basic types of components used in environmental systems. Simple variations of basic symbol types are provided. Words on the schematic diagram, special symbol codes, or symbols that combine basic symbol types (Section 5) can be used to augment the basic symbols when appropriate. Special or combined symbols not contained in this document should be defined on the schematic diagram. An example of a complete schematic is given in Section 6. A bibliography of other documents on environmental system symbols is found in Appendix A.
AC-9 Aircraft Environmental Systems Committee
Standard for Refrigerant Risk Analysis for Mobile Air Conditioning SystemsJ2773_202005 (Current)5/15/2020
This SAE Standard describes methods to understand the risks associated with vehicle mobile air conditioning (MAC) systems in all aspects of a vehicle’s lifecycle including design, production, assembly, operation, and end of life. Information for input to the risk assessment is provided in the appendices of this document. This information should not be considered to be complete, but only a reference of some of the data needed for a complete analysis of the risk associated with the use of refrigerants in MAC systems.
Interior Climate Control Vehicle OEM Committee
Air Conditioning of Aircraft CargoAIR806B (Current)5/12/2020
The report presents air conditioning data for aircraft cargo which is affected by temperature, humidity, ventilation rate and atmospheric pressure. The major emphasis is on conditioning of perishable products and warm-blooded animals. The report also covers topics peculiar to cargo aircraft or which are related to the handling of cargo.
AC-9 Aircraft Environmental Systems Committee
Fire Containment Cover - Operation and UseARP6905 (Current)4/23/2020
This SAE Aerospace Recommended Practice (ARP) provides guidelines for the effective operation and use of fire containment covers (FCCs). Technical Standard Orders (TSOs) C203 and C90e (and later revisions) incorporate AS6453, and provide the Minimum Performance Standards (MPS) for an FCC design. The net and pallet used with the FCC must be approved using the updated net and flammability requirements in TSO C90e and later revisions. However, fire containment performance also requires this equipment is properly used. Fire safety is compromised when FCCs are used in an inadequate manner.
AGE-2 Air Cargo
Procedure for Certification that Requirements for Mobile Air Conditioning System Components, Service Equipment, and Service Technician Training Meet SAE J StandardsJ2911_202002 (Current)2/3/2020
This SAE standard provides manufacturers/marketers, testing facilities, and providers of technician training with a procedure for certifying compliance with the applicable standard. Manufacturers/marketers or sellers who advertise their products as certified to an SAE J standard shall follow this procedure. Certification of a product is voluntary; however, this certification process is mandatory for those advertising meeting SAE standard(s) requirements. Only certifying to this standard allows those claiming compliance to advertise that their product (unit), component, or service technician training meets all requirements of the applicable SAE standard. Certification of compliance to this and the appropriate standard and use of the SAE label on the product shall only be permitted after all the required information has been submitted to SAE International and it has been posted on the SAE website. This process is mandatory for those advertising as being “Certified to SAE JXXXX-(version)” [appropriate SAE standard] requirements or any advertising or labeling language that implies such certification. SAE International will post the results in the official SAE online database. SAE J2911 requires manufacturers/marketers, testing facilities, and technician training providers to comply with different requirements. This document covers requirements for MAC system components, service equipment, and printed training manuals that are different in content. Therefore, for consistency of reference in this standard, they are identified for general reference as a “product.” Additionally, a reference in this standard to an applicable standard is used as a general term and it refers to the document that defines the requirements, such as Section 609 of the Clean Air Act. Regulatory agencies will also have access to the SAE International public posting of the results in the official SAE database.
Interior Climate Control Steering Committee
HFC-134a (R-134a) Recovery/Recycle/Recharging Equipment for Mobile Air-Conditioning SystemsJ2788_202001 (Historical)1/3/2020
The purpose of this SAE Standard is to establish the specific minimum equipment performance requirements for recovery and recycling of HFC-134a that has been directly removed from, and is intended for reuse in, mobile air-conditioning (A/C) systems. It also is intended to establish requirements for equipment used to recharge HFC-134a to an accuracy level that meets Section 9 of this document and SAE J2099. The requirements apply to the following types of service equipment and their specific applications. a Recovery/recycling equipment b Recovery/recycling-refrigerant charging c Refrigerant recharging equipment only
Interior Climate Control Service Committee
Superior Interiors20AVEP01_031/1/2020
New-mobility thinking is changing how vehicle interiors will work for everyone. Future-vehicle interior renderings have always stoked our imaginations for what may be possible in the cabin environment. Automated vehicle (AV) developments, including high-function driver assistance features and mobility as a service (MaaS), are bringing new dimensions to those possibilities. Ironically, while near-term prospects for privately-owned autonomous (SAE Level 4) AVs have hit the hype curve's downward slope, research and development into how passengers will interact with new-mobility technology promises interior designs and features that will likely be on the market long before most consumers experience self-driving cars.
Visnic, Bill
Laser-Based System Detects Fires Even in Dusty, Harsh EnvironmentsTBMG-357561/1/2020
Researchers have developed a new laser-based system that offers an efficient and low-cost way to detect fires in challenging environments such as industrial facilities or large construction sites. With further development, the system could eventually detect fires that are more than a kilometer away. It could be used in a variety of industries such as waste management facilities, power supply plants, food processing factories, and textile factories.
Collaborative Automation: It's More Than Just the CobotTBMG-3560812/1/2019
Collaborative robots, often called “cobots,” offer opportunities for companies of almost any size to cost-effectively automate processes that were previously out of reach. Cobots are available in a wide range of sizes, payloads, and capabilities but they all share attributes that define the term “collaborative.” The aspect that most people think of first is safety — the ability for cobots to work alongside human workers without bulky, expensive guarding. Cobots include a number of built-in safety mechanisms including rounded edges and softer materials as well as power-and force-limiting technologies that avoid injury and minimize discomfort in case of contact, and sensors that automatically slow or stop the robot arm if a human enters its workspace.
Q&A: Refrigeration by Twisting FibersTBMG-3571312/1/2019
Dr. Ray Baughman, Director of the Alan G. MacDiarmid Nano Tech Institute at the University of Texas, Dallas, and his team discovered a new technology for refrigeration that is based on twisting and untwisting fibers.
Transport Method Boosts Capacity of Heat ExchangersTBMG-3572312/1/2019
Turbulent heat exchange is a method of heat transport widely used in heating, ventilation, and air conditioning (HVAC) systems. Adding a readily available organic solvent to common water-based turbulent heat exchange systems can boost their capacity to move heat by 500%. Other methods for increasing heat flux — nanoparticle additives or other techniques — have achieved about 50% improvement.
Simulation Study on Driving Range at High and Low Temperature2019-01-507111/4/2019
With the popularity of EVs, driving range has become one of the focuses of people's concern. The anxiety about driving range was particularly evident in winter and summer, because of the use of air conditioning at high temperatures and heating at low temperatures, as well as the power supply capacity of power batteries at different temperatures. At the same time, the energy consumption of thermal management components and the influence of thermal management on the efficiency of other components also need to be considered. The high and low temperature driving range is studied by means of simulation, which has the characteristics of low cost and fast speed. For the vehicles simulated in the article, driving range at 25 °C is 240 km, at -30 °C reduced to 34% (81.9 km), at 40 °C reduced to 73% (176 km). In this paper, the simulation modeling and analysis on the driving range of an EV are carried out. The simulation model includes air conditioning system and crew cabin, power battery system and its cooling system, motor system and its cooling system, driving system and control system, etc. This paper provides a simulation method and research method for studying the performance of EVs at high and low temperature, and provides a theoretical basis and realization form for improving driving range by means of control and parts optimization.
Yu, Jiang, Nie, YanXin, MingJun, Dong, Xie, Ning, Ma, BaoTong, Xu, Zhe
2019 'Create the Future' Sustainable Technologies Category Winner: Wave-Powered Water DesalinationTBMG-3544911/1/2019
Demand Side Load Management by Using Priority Based Load Shedding Algorithm with and without Renewable Energy Generation2019-28-007310/11/2019
Demand side load management (DSLM) emphasizes control of the power demanded, by reducing the peak load and control of energy utilization of the system. DSLM is introduced to improve the flexibility of the grid power usage and also to aid the utilization of Renewable Energy Generation (REG) which is intermittent. In this work, implementation of load shedding (LS) algorithm for the residential load is performed with the limit of power as constraint, considering REG and grid in three different modes of operation. Solar and Wind power are the REG considered in this work. Priority Based Load Shedding (PBLS) is performed to limit the power consumption of equipment during peak hours with the implementation of varying pricing signal. In order to implement PBLS, three residential user load data for 24 hours is considered. The users are categorized as low, medium and high priority user. The priority of the user is based on the load consumption for 24 hours. The proposed LS scheme is performed, depending on the power requirements of Home Electric Devices (HEDs) and the priority of consumer. The main objective of cost reduction (power consumption) along with minimization of user discomfort is achieved by using the PBLS algorithm. Simulation results for REG islanded mode, grid connect mode and REG aided grid mode is performed. The further cost comparison is made with and without a load schedule. The scheduling of load curve is performed using Genetic Algorithm (GA) optimization.
Rathinam, Rajarajeswari, Dayalan, Suchitra
SAE Truck & Off-Highway Engineering: October 201919TOFHP1010/3/2019
On the verge of the Digital Age Increasingly connected electrohydraulic systems and machine controls allow the high degree of controllability that's essential for automated operations. Miserly power systems Engineers push engine, transmission technologies to turn off fuel usage. All options on the table Powertrain developers who spoke at SAE COMVEC are leaving no stone unturned in their quest to trim emissions. Cab air quality: A critical component of operator comfort Focus on defining cab air quality, measuring it, and designing the needed performance into cabin designs and HVAC systems is intensifying. Expanding fast charging faster Tritium works to accelerate installation of DC fast-charging infrastructure to keep up with growing demand for commercial EVs. Editorial Word on the street at COMVEC Link digital suspension uses sensors, ECU to keep cabs stable Knapheide saves costs, time by moving vehicle life testing in-house Ford revisits OHV layout, big displacement for new commercial-truck V8 Design tools ensure component compatibility, create autonomous driving tests How HMI displays impact operator productivity in industrial vehicles Truck OEMs intensify focus on customer experience, telematics to keep fleets up and running Q&A CNH Industrial's Hubertus M. Mühlhäuser discusses separating its On- and Off-Highway businesses, big investment in Nikola
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.
Passenger Vehicle Windshield Demisting and Defrosting SystemsJ902_201909 (Current)9/25/2019
This SAE Recommend Practice establishes for passenger cars, light trucks, and multipurpose vehicles with GVW of 4500 kg (10000 pounds) or less, as defined by EPA, and M1 category vehicles as defined by the European Commission:
Interior Climate Control Vehicle OEM Committee
Energy Recovery Rate from an Electric Air-Cycle System under the Cruising Altitude and Speed2019-01-19059/16/2019
A new electric air-cycle system of aircrafts is investigated focusing on energy recovery from the exhaust air. The working fluid of air has the higher energy level in the cabin than in the outside during the cruise because the outside air is at low pressure and low temperature. In the system, by setting a recovery turbine behind the cabin, the discharged energy can be collected, although the working fluid through the system has been only discharged from the cabin into the outside. We perform a thermodynamic cycle-analysis, where the temperature, pressure, entropy, etc. are calculated at each position of the cycle by considering the two pressure ratios of the compressors as variable parameters to show T-s diagram. In addition, we obtain an energy recovery rate of the recovery energy to the necessary power for the electric compressor. The energy recovery rate is roughly estimated 40-80% under the reasonable practical operating conditions.
Adachi, Takahiro, Seki, Naoki, Oyori, Hitoshi, Muraoka, Mikio
Measurement of Passenger Compartment Refrigerant Concentrations Under System Refrigerant Leakage ConditionsJ2772_201909 (Current)9/3/2019
This Standard is restricted to refrigeration circuits that provide air-conditioning for the passenger compartments of passenger and commercial vehicles. This Standard includes analytical and physical test procedures to evaluate refrigerant concentration inside the passenger compartment. In the early phases of vehicle evaluation, usage of the analytical approach may be sufficient without performing physical tests. The physical test procedure involves releasing refrigerant from an external source to a location adjacent to the evaporator core (inside the HVAC module). An apparatus is used to provide a repeatable, calibrated leak rate. If the system has multiple evaporators, leakage could be simulated at any of the evaporator locations. This standard gives detail information on the techniques for measuring R-744 (CO2) and R-1234yf (HFO-1234yf), but the general techniques described here can be used for other refrigerants as well.
Interior Climate Control Vehicle OEM Committee
Design of an Energy-Efficient Critical Angle Lens ReflectorTBMG-347687/1/2019
The critical angle lens reflector has commercial applications that supersede ordinary mirrored reflectors. The physics of the critical angle lens reflector are based on the optics principle of total internal reflection. Total internal reflection is characterized as follows: (1) as shown in Figure 2, the light rays are reflected off of the reflecting surface whereby the angle of reflection – with respect to the perpendicular to the reflecting surface – is equal to the angle of incidence of the ray, and (2) the reflection of the light ray takes place with no loss of energy upon reflection.
Modeling of Micro-Perforated Heat Baffle2019-01-15826/5/2019
Classical porous materials are used throughout the automobile with usually good success but there are limitations to their performance in areas where there are adverse environments. An example of this is the transmission tunnel section under the automobile, where there exist high air flow velocities and temperatures which will lead to quick deterioration of the material. Micro-Perforated Heat Baffles (MPHB) are showing success in the heating, ventilating, and air conditioning industry, and therefore there is an effort in applying MPHB extensively in the automotive field. The question with regards to which micro-perforation pattern gives the best performance plus where and how much should be allocated in the automobile still remains. This paper shows how to address these issues by applying Hybrid Statistical Energy Analysis (HSEA) technology. An expression for the Absorption Coefficient (AC) which incorporates the micro-perforation pattern is explained. This equation models the absorption of sound due to friction losses in the holes. Thereafter calculations for flat sample AC are completed and good correlation with experimental data is shown. Flat sample AC is necessary to know but by itself it does not answer the important question whether SPL suppression is being realized on a real car and how this is addressed without building multiple prototypes. Thus, the paper emphasizes the importance of having a HSEA model and how with this model an noise and vibration specialist can run multiple MPHB concepts. This paper shows this capability by applying MPHB to cover the transmission tunnel under the automobile and the calculated SPL under different input modes such as road noise and engine noise.
Teagle-Hernandez, Allen, Ide, Fumihiko, Ichikawa, Shota, Yabe, Kengo, Matsuda, Takehisa
The Mechanism of Hissing Noise in the Automotive Cabin and Countermeasures for its Reduction2019-01-14746/5/2019
The automotive refrigerant system can occasionally exhibit an excessive noise out of air-conditioner (A/C) vents during vehicle’s developments. If the vehicle has been parked for long hours in summer and the A/C system is turned on, sometimes hissing noise is induced by the refrigerant flow. In order to understand the mechanism, a lot of bench and vehicle tests were conducted. However, there is still not enough to understand the physical behavior in detail. Therefore, for the first step, the visualization method to capture the behavior of multi-phased refrigerant flow jet inside the pipe was proposed with a high-speed camera, some light devices and acrylic test piece. In addition, image analysis to quantify the flow regime from a series of observed snapshots. Using proposed method, the correlation study between flow and noise was performed at A/C bench test. As a result, different flow features such as the velocity can be observed in the occurrence of the noise or not. It is also shown that the valve tends to open largely when it occurs. As another approach to clarify the mechanism, co-simulation method was developed with computational fluid dynamics (CFD) and vibro-acoustic model. Pressure fluctuations on the inner wall of the pipe are calculated by CFD and they are imported to vibro-acoustic model as transient pressure load. Structural modes in the evaporator system and acoustic sensitivity in heating, ventilation and air conditioning (HVAC) are calculated and then the frequency characteristics are revealed. Lastly, from the perspective of both fluid and vibro-acoustic field, some countermeasures for its reduction are discussed.
Itoh, Atsushi, Wang, ZongGuang
Assessment of Automotive Environmental Noise on Mobile Phone Hands-Free Call Quality2019-01-15976/5/2019
Environmental noises such as wind, road, powertrain, and HVAC noise are important aspects to consider when implementing a hands-free terminal for mobile phone calling from within a car. Traditionally, these environmental noises have been exclusively considered for driver comfort; however, with the introduction of the hands-free terminals (HFT) and increasing consumer demand relative to mobile phone call quality, a broader implication of high background noise levels should be considered. HFT algorithm development and implementation can and does provide a high level of background noise suppression to mitigate these concerns, but this is often done at the expense of computational power and cumulative delay during a phone call. The more advantageous solution would be to address the problem from a source and path perspective with emphasis on reduction of noise in the frequency bands which most influence call quality performance. The assessments shown throughout this paper establish a sensitivity of HFT call quality to background noise levels based on industry-standard metrics, including those defined by International Telecommunication Union (ITU) standards. These assessments were established based on a series of experiments that include characterizing vehicle to vehicle variability with a common background noise and single vehicle sensitivity to reductions in background noise. In the background noise sensitivity investigations, filtering investigations were conducted to identify the frequency ranges which drive the most significant degradation in speech intelligibility and HFT performance. The information gained provides insight regarding the requirements for mitigating background noise in the context of both customer comfort as well as HFT performance, both of which are key factors in the perception of overall vehicle quality.
Pruetz, Jeffrey, Watson, Channing, Tousignant, Todd, Govindswamy, Kiran
Towards a Quiet Vehicle Cabin Through Digitalization of HVAC Systems and Subsystems Aeroacoustics Testing and Design2019-01-14766/5/2019
With the rise of electric autonomous vehicles, it has become clear that the cabin of tomorrow will drastically evolve to both improve ride experience and reduce energy consumption. In addition, autonomy will change the transportation paradigm, leading to a reinvention of the cabin seating layout which will offer the opportunity to climate systems team to design quiet and even more energy efficient systems. Consequently, Heat and Ventilation Air Conditioning (HVAC) systems designers have to deliver products which perform acoustically better than before, but often with less development time. To success under such constraints, designers need access to methods providing both assessment of the system (or subsystems) acoustic performance, and identification of where the designs need to be improved to reduce noise levels. Such methods are often needed before a physical prototype is requested, and thus can only be achieved in a timely manner through digital testing. Previous studies have demonstrated the ability of a CFD/CAA approach based on the Lattice Boltzmann Method (LBM) to predict HVAC system noise including real and complex ducts, registers, mixing unit and blower geometries. This LBM low dissipative numerical approach has indeed been shown to accurately capture turbulent and convective mechanisms and to propagate acoustic waves in ducted systems and in free-field. Combined with a noise source identification strategy, these methods provide the ability to visualize the noise sources inside the system, as well as to identify and rank noise-generating design features - a unique design methodology not available with physical testing. In this paper, such an approach is presented based on two HVAC systems layout, targeting two different vehicles. To answer the need for systems and subsystems predictions, simulation results are correlated to experiment for configurations with blower alone, blower + air intake, and for full HVAC system (blower + air intake + mixing unit). Finally, an in-depth analysis of the flow noise sources contributions to a microphone location is performed, and countermeasures are discussed.
Vidal, Vincent, Mann, Adrien, Verriere, Jonas, Kim, Minsuk, Ailloud, Fabrice, Henner, Manuel, Cheriaux, Olivier
Paradigm shift in NVH19AUTP06_026/1/2019
A new wave of vehicle technologies is changing the way Brüel & Kjaer attacks noise, vibration and harshness. When you're in the business of NVH solutions, you get to know noise and vibration up close and personal. And for these experts, it can be difficult to sequester the ‘N and V’ throughout their own day. Ask Dr. Gabriella Cerrato, manager of global sound and vibration engineering services at Brüel & Kjaer. “I can't be in a hotel room and not be aware of things like the refrigerator compressor, the ice maker, or the air conditioning,” she noted. “Although I'm not a geek about it-I don't immediately ponder the sources and potential noise paths of the hotel HVAC, for example-it sometimes drives me nuts.”
Brooke, Lindsay
Electron Beam Heating and Atomic Restructuring of Sapphire SurfacesTBMG-343965/1/2019
NASA’s Langley Research Center has developed a new way to reduce the high-temperature heating requirement of sapphire substrates in wafer production. The growth of high-quality and single-crystal epitaxy layers on sapphires requires uniform and high-temperature heating to accommodate restructuring of the sapphire surface to be aluminum-terminated. These requirements (uniform heating and re-structuring of sapphire substrates) are challenging for high-yield and high-quality production. This innovation offers a new way to reduce the high-temperature heating requirement of sapphire substrates and at the same time create the morphological restructure of sapphire surface required.
R410A Based Automotive Heat Pump System That Hits Cabin Heating Goal Successfully in -30 °C Extreme Ambient2019-01-09104/2/2019
To meet low ambient challenges on Battery based Electric Vehicles (BEV), it is necessary to employ heat pump systems on the HVAC systems. However, due to the boiling points limitation of the regular refrigerant R134A/R1234YF, even with Vapor Injection cycle (VI) added, due to -26°C Boiling Temperature (BT) limitation, it is still encountering serious challenges to meet -30 °C or lower ambient needs, although VI Heat Pump (VI H/P) may reach COP>=1.7 at ambient -18 °C. An alternative low BT refrigerant, R410A, plus VI participation, the combination provides potentials to operate in extreme low ambient like -30 °C. In order to find out the actual heating performance of R410A+VI, a demonstration fleet of three vehicles had been built up for road tests to compare each other, which consists of a traditional vehicle (ICE gas heating), a BEV with PTC water heating system (R134A) and a BEV with VI heat pump system (R410A). The testing area covers the coldest city in China such as Harbin, (-20°C), Yakeshi (-39 °C), The road tests have exhibited positive results that the R410A based VI H/P cabin heating system fulfills requirements essentially both for passengers comfort and defrosting/demising. This paper is to summarize the information of the experiments related, including vehicle information, H/P thermal loop, the components applied etc. Meanwhile, it opens some environmental concerns of R410A application on vehicular HVAC systems.
Zhai, Kelvin, Chen, Xuefeng
Analysis and Model Validation of the Toyota Prius Prime2019-01-03694/2/2019
The Toyota Prius Prime is a new generation of Toyota Prius plug-in hybrid electric vehicle, the electric drive range of which is 25 miles. This version is improved from the previous version by the addition of a one-way clutch between the engine and the planetary gear-set, which enables the generator to add electric propulsive force. The vehicle was analyzed, developed and validated based on test data from Argonne National Laboratory’s Advanced Powertrain Research Facility, where chassis dynamometer set temperature can be controlled in a thermal chamber. First, we analyzed and developed components such as engine, battery, motors, wheels and chassis, including thermal aspects based on test data. By developing models considering thermal aspects, it is possible to simulate the vehicle driving not only in normal temperatures but also in hot, cold, or warmed-up conditions. Next, we analyzed supervisory vehicle control to merge the separately developed vehicle component models in a vehicle simulation model. The supervisory vehicle control includes engine on/off, battery energy management, engine operating conditions, and so on. In particular, we analyzed the control changes according to the warmed-up start and heating, ventilation, and air conditioning operation. We implemented and integrated the analyzed component models in a vehicle simulation model in Autonomie for the Toyota Prius Prime. In most cases, model predictions of fuel economy were within 5% of the experimental value, which is within the range of test-to-test variability. Many of operational signals, including battery state of charge matched well.
Jeong, Jongryeol, Kim, Namdoo, Stutenberg, Kevin, Rousseau, Aymeric
Crew Rest FacilitiesARP4101/3A (Current)4/1/2019
This document recommends criteria for the design and installation of flight crew rest facilities (FCRF) on transport category aircraft when operations with an augmented flight crew are performed. NOTE: Within this ARP, the term “must” will indicate items required for compliance with outside known government regulations, especially 14 CFR Part 117. “Shall” describes sections which are required if this ARP is used as a means of compliance. The term “should” will indicate optional requirements, preferences, and recommendations of the approving SAE committee. Wherever noted and bracketed as [FAA] or [EASA], this document includes agency regulations for reference that are not otherwise evaluated herein.
S-7 Flight Deck Handling Qualities Stds for Trans Aircraft
See-Through Film Rejects 70 Percent of Incoming Solar HeatTBMG-341664/1/2019
A heat-rejecting film was developed that could be applied to a building’s windows to reflect up to 70 percent of the Sun’s incoming heat. The film remains highly transparent below 32 °C (89 °F). Above that temperature, the film acts as an “autonomous system” to reject heat. If every exterior-facing window in a building were covered in this film, air conditioning and energy costs could drop by 10 percent.
R-1234yf Service Hose, Fittings and Couplers for Mobile Refrigerant Systems Service EquipmentJ2888_201902 (Current)2/11/2019
This SAE Standard covers fittings, couplers, and hoses intended for connecting service hoses from mobile air-conditioning Systems to service equipment such as charging, recovery and recycling equipment. (Figure 1) This specification covers service hose fittings and couplers for MAC service equipment service hoses, per SAE J2843 and SAE J2851, from mobile air-conditioning systems to service equipment such as manifold gauges, vacuum pumps, and air-conditioning charging, recovery and recycling equipment.
Interior Climate Control Service Committee
An Examination of Comfort and Sensation for Manual and Automatic Controls of the Vehicle HVAC System2019-01-50051/15/2019
The fast-changing and asymmetrical nature of the cabin environment challenges climate control systems in maintaining occupant comfort. This article examines the relationship between the control that occupants have over the heating, ventilation, and air conditioning (HVAC) system and their perceived comfort within the surrounding thermal environment. Three test cases using automatic control (20°C, 22°C, 24°C) and one in manual mode were evaluated via driving trials under normal road conditions in the United Kingdom during winter. In these trials, car cabin occupants felt more comfortable when using manual control than automatic (Fisher’s test, p = 2.2 × 10−16). Occupants felt neutral thermal sensations at head and foot level when using manual control. At chest level, occupants felt thermally neutral for both automatic and manual controls. This research highlights the need for further exploration of the interaction of the cabin occupants with their HVAC systems and the impact it has on their comfort perception.
Petre, Alexandra Galina, Brusey, James, Wilkins, Ross
Comfort Improvement in Air Conditioned Buses through the Homogenous Air Flow along the Hatrack by Using Different Types of Baffle Plates2019-26-03671/9/2019
India being a developing nation, there is significant improvement of road infrastructure across the country as well as the spending power and earnings of the common man. This leads to the new trend of customers willing to pay for a more comfortable travel through AC buses. To satisfy these demands, OEM’s are forced develop and manufacture huge numbers of AC buses. Although the OEM’s are meeting this demand of quantity, the quality aspect of the buses, i.e., climate comfort, is still subpar. One of the main reasons for this sub-quality comfort is the non homogenous distribution of air flow along the bus. This non homogeneity leads to the centre of the bus having very high air flow and thus overcooling conditions, while the front and rear of the bus receive very little air flow and thus receive under-cooling conditions. To solve this concern of non homogeneity, we incorporated a new design in the hatrack, through the implementation of baffles and deflector in the hatrack. With this new design, air flow distribution was analyzed through CFD and corroborated with the physical trial of a vehicle with this new design. The results of the air flow variation, achieved through the physical trial of the vehicle, was that of homogenous air flow distribution with a variation of 1 m/s between front, middle and the rear zone of the hatrack. We then went on to implement this new design in few of the buses sold to customer. The feedback from the customers, received by us, was overwhelmingly positive and was encouraging, leading to roll out implementation of this new design for all production buses.
Sharma, Saurabh, Sathish, Akarsh, Thakur, Jitendra, Shende, Sushil
Ancient Pigment Can Boost Energy EfficiencyTBMG-336171/1/2019
Egyptian blue, derived from calcium copper silicate, was routinely used on ancient depictions of gods and royalty. Previous studies have shown that when Egyptian blue absorbs visible light, it then emits light in the near-infrared range. In fact, the pigment's fluorescence can be 10 times stronger than previously thought.
Does Your Coating System Require Climate Control? What to Look For and What to ExpectTBMG-3342212/1/2018
There is one aspect of the paint and coatings finishing business virtually guaranteed to give the budget director heart failure: climate control. There's no way around it – climate control systems are expensive.
Sterilizing Fogger Cleans Ambulances with a BreezeTBMG-3340312/1/2018
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.
2019 Honda Pilot gets refined 9-speed, tougher styling18AUTP10_1310/1/2018
The 2019 Honda Pilot arrives with few but important changes for the 3-row, 8-seat SUV, most notably revisions to its 9-speed automatic. New, more-rugged exterior styling is designed to remind consumers the Pilot has a thoroughly capable torque-vectoring all-wheel-drive setup, and Honda's suite of radar-based safety systems is now standard on all Pilot models. Meanwhile, extensive cabin tech upgrades include a welcome return of the volume knob to the central touchscreen and other refinements to the infotainment interface, plus and an available 4G LTE Wi-Fi hotspot.
Seredynski, Paul
Computational fluidodynamic study applied in incompressible air flow in automotive duct2018-36-00879/3/2018
The design of air ducts of an Automotive Ventilation System presents as one of the complicators the restriction of space. In its design a symmetrical configuration is not always possible, due to the presence of anothers components of the vehicle, thus the ducts are distributed in asymmetric structures and normally have sharp curves, configurations that contribute to the loss, irregular distribution of the flow and production of noise. This work presents a numerical study of the incompressible flow of air in the ducts of an automotive ventilation system. The purpose is to study and compare the behavior of the fluid dynamic flow, the loss on the process and the flow distribution between two different ducts: one with symmetrical geometry and the other one with asymmetrical geometry. The study was performed using commercial software Star CCM +® that employs finite volume method. The results for each type of duct were relevant to the conclusion that the non-symmetry of the ventilation duct causes significant impacts. The symmetric duct geometry resulted in similar values for the air flow at diffuser placed on right and left side at car console, on the other hand, the asymmetric duct geometry had 7.89% more air flow rate at the right vent compared to the left vent. The pressure found for the symmetric geometry was 3.9% higher than relative asymmetric geometry. With this study, it was possible to visualize the impact that the space constraint, consequently the asymmetrical geometry, induced in the quality of the vehicle's air conditioning system.
Oliveira e Caldeira, Luiz Guilherme de, Capanema, Matheus Figueiredo, Fonseca de Souza, José Leôncio
Water-Based Battery Stores Solar and Wind EnergyTBMG-324768/1/2018
Wind and solar energy generation creates challenges, since the Sun only shines by day, and sometimes the wind doesn't blow. Another variability is surges of demand on the grid. On a hot day when air conditioning is in use, utilities must have load-balancing strategies to meet peak demand. A water-based battery was developed that could provide a cheap way to store wind or solar energy generated when the Sun is shining and wind is blowing so it can be fed back into the electric grid and be redistributed when demand is high.
Magnetic Induction Heating of Space Foods During Dispensing Under Weightless ConditionsTBMG-290516/1/2018
Hot foods are psychologically pleasing. Food heating systems are currently part of the astronaut feeding program. An electrical method of heating foods during dispensing in space uses magnetic induction heating. The process is up to 95% efficient in converting electricity into food heat during the process of dispensing. There is no direct contact between the electrical source and the food.
Modularized Simulation Tool to Evaluate Battery Solutions for 12 V Advanced Start Stop Vehicles2018-01-04464/3/2018
The 12 V advanced start stop systems can offer 5-8% fuel economy improvement over a conventional vehicle. Although the fuel economy is not as high as those of mild to full hybrids, its low implementation cost makes it an attractive electrification solutions for vehicles. As a result, the 12 V advanced start stop technology has been evolving fast in recent years. On one hand, battery suppliers are offering a variety of energy storage solutions such as stand-alone lead acid, stand-alone LFP/Graphite, dual batteries of lead acid parallel with NMC/LTO, LMO/LTO, NMC/Graphite, and capacitors, etc. For dual battery solutions, the architecture also varies from passive parallel connection to active switching. On the other hand, OEM are considering to leverage a lot more use out of traditional 12 V SLI (start, light, and ignition) for functions such as power steering, air conditioning, heater, etc. Depending on battery architecture and vehicle functioning design, the energy management strategy can easily become complicated. Since many variables are involved in the design of 12 V advanced start stop systems, an integrated simulation tool with a couple of modularized models including vehicle, batteries, and performance characterization have been developed. The modularized tool would help to evaluate many aspects of the design from motor size selection, power network management, battery evaluation, testing standardization. As a specific demonstration, in this work, we use the tool to compare three chemistries: stand-alone AGM, stand-alone LFP, and dual batteries of lead acid and LTO for different driving cycles including NEDC, WLTP, FTP72, and HWFET as function of motor size.
Zhang, Zhenli, Jin, Zhihong, Watson, Thomas
Transient Analysis of Natural Convection around a Pair of Circular Cylinders inside a Square Enclosure2018-01-07764/3/2018
Heat exchangers are widely used in various transportation, industrial, or domestic applications such as thermal power plants, means of heating, transporting and air conditioning systems, electronic equipment and space vehicles. In all these applications improvements in the efficiency of the heat exchangers can lead to substantial cost, space and material savings. Hence considerable research work has been done in the past to seek effective ways to improve the efficiency of heat exchangers. In this paper the effect of natural convection is justified between exterior solid wall surfaces and the surrounding air inside the enclosure. Designing of electronic devices, heavy industrial equipments such as boilers, turbines etc. and building aerodynamics are some of the real world application associated with this study. The referred investigation includes the phenomenon of natural convection process to analyses the pattern of heat transfer characteristics inside a square enclosure with two circular cylinders placed at different position inside it. Maximum heat exchange zones are identified so that goal of effective heat transfer can be achieved which helps the heat exchangers to work efficiently at every condition. However, in the present work only unsteady state natural convection technique has been considered. The study of unsteady state natural convection in a square enclosure with conjugate boundary condition is done numerically. The analysis is performed on a square enclosure within which are placed two circular cylinders eccentrically. The enclosure walls are maintained at low temperature to that of cylinders such that a temperature difference is maintained between both the bodies. The cylinders are tilted at different angles inside the enclosure. A transient state 2-D numerical investigation is conveyed for air as an enclosed fluid. The Rayleigh number is varied in the range of 103 to 106 and the results are summarized in a relative manner. The value of Prandtl number is kept constant i.e. 0.71 corresponding to that of the air. The effect of orientation of the two cylinders and the outcome of the variation of Rayleigh number is calculated with the help of corresponding streamlines, and temperature distribution.
Tomar, Mukul, Kumar, Naveen, Malhotra, Aahan
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