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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
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
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
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
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
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
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
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
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.
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
Evaluation Method of Thermal Sensation and Comfort for Air Conditioning Performance Reduction2018-01-07754/3/2018
As a method of maintaining thermal sensation and comfort inside a passenger compartment, not only a conventional HVAC system but also a combination of a HVAC system and other devices such as seat heaters, a steering wheel heater, ventilation seats are increasing. This research developed a method to evaluate thermal sensation of a human body when using these various thermal control devices. This method can evaluate the heat balance of the human body by calculating the amount of heat exchange between a human body and the external environment, and it takes into consideration the influence of heat exchange by heat conduction with seats or a steering wheel. The human thermal model is made by dividing a human body into various segments, and it is the model that considers heat transport by blood flow for each segment. As a result of a heat balance of a human body, it is possible to derive the standard environmental temperature which is named the local-body standard new effective temperature (local SET*) for each part of a human body. Local thermal sensation is defined by a model equation that takes into consideration transient changes of a heat balance and an influence of heat storage by a whole body. Therefore, it is possible to evaluate thermal comfort of occupants in a vehicle cabin in transient and non-uniform situation. The authors conducted the experiment using actual vehicles and evaluated how much thermal sensation changes when an air conditioning system is different, using this evaluation method. Energy measurements for maintaining vehicle cabin environment and thermal sensation in the vehicle cabin were simultaneously carried out and the results of thermal sensation evaluation were shown.
ITO, Yusuke, Sakoi, Tomonori, Miyamoto, Takeshi
A Novel DoE based Front-End Airflow Target Setting Approach for Optimum HVAC Cool Down Performance2018-01-07864/3/2018
The front-end air flow conditions have a substantial impact on the cool down performance of a vehicle Heating, Ventilation and Air-Conditioning (HVAC) system. The performance of a mobile HVAC system is analyzed by conducting tests on the vehicle in a drive cell, subjecting it to different drive cycles. This now can be done virtually using system level simulation or one-dimensional (1D) tools. Target values for condenser air inlet velocity and temperature for these HVAC performance focused drive cycles needs to be established during the development phase to meet the cool down functional objectives of the vehicle. Thus, in the early stages of development, 1D tools play a major role. Condenser air flow should be sufficient and the temperature should be as low as possible at different vehicle operating conditions to have good air-conditioning (AC) performance. This paper focuses on a Design of Experiments (DoE) approach to investigate the effect of condenser air inlet conditions on overall AC performance and introduces an effective target setting strategy to help move towards an optimal front-end module design. First, a Central Composite DoE (CCD) study is conducted to show how condenser air inlet conditions: air inlet velocity and temperature at different vehicle speeds affect the cool down functional objectives. Second, after identifying the most contributing factors, a novel target setting strategy is proposed to accurately identify the required condenser air inlet velocity and temperature conditions for optimum AC performance. This new strategy can guide the engineers to design more efficient front-end cooling modules to meet all the requirements of AC system and passenger comfort. The simulations and DoE are both done using Siemens’ LMS Imagine. Lab AMESim 15.
Mirzabeygi, Pooya, Natarajan, Shankar, Flanagan, Allan
Numerical Simulation of Oil Separator of an Automotive Swash Type Compressor2018-01-04884/3/2018
In the present study a numerical investigation is performed by using computational fluid dynamics (CFD) aiming to figure out and maximize the separation efficiency of an oil separator by changing the various design parameters. A typical automotive swash plate type compressor is chosen for this numerical investigation. Basically oil separation becomes very important where oil return is quite problematic due to the multiple constraints in piping layout design. Efficient oil separation makes the compressor lubrication easy and prevents from seizing during running. It also enhances the heat transfer from heat exchanger by reducing or separating oil from the refrigerant flowing in the air conditioning (AC) circuit. A computational method is proposed to analyze an oil separator fitted in a swash plate compressor. Eulerian multiphase model is employed to simulate the oil and refrigerant mixture model. Separation efficiency is predicted numerically by changing the nozzle diameter, separator diameter and height. Further to that a different approach (based on density difference) is utilized to maximize the separation percentage. It is observed that by employing such approach separation efficiency increased drastically. Thus a numerical method is established for predicting oil separation which becomes key element in the early stage of compressor design to avoid field failure.
Sen, Somnath
Selection and Thermal Modeling of an Automotive Blower Motor by Using CFD and Its Experimental Validation2018-01-00734/3/2018
The present paper outlines the selection and numerical modeling of a high performance and efficient blower motor fitted in an automotive Heating ventilation and air conditioning (HVAC) system. In today’s scenario blower motor is present in almost every car whether fitted with AC system or only blower system. The selection of a blower motor is very important in terms of delivering right amount of airflow with minimum consumption of electric power. As the power consumption goes up it may impacts in indirect green house gas (GHG) emission from a vehicle. While it does so e.g. fulfills HVACs’ airflow need, it generates some amount of heat which is very detrimental for its life and overall performance as well. Also the generated heat may lead to increase in temperature of the main stream air flow causing reduction in the cabin cooling and eventually hampers the comfort level. The present study describes the methodology of selecting an automotive blower motor and its thermal modeling by using computational fluid dynamics (CFD). It involved the two different alternative methods of selecting the motor with the help of motor characteristics, fan characteristics and system resistance. The later method was adopted in selecting the motor in current study while the system resistance was evaluated numerically. Motor torque was estimated and electric power consumption was derived. Further to this the motor was modeled in CFD in detailed with its internal components like brush, commutator, armature etc. and then airflow and thermal analysis were carried out by conjugate heat transfer. Heat generated by the motor was modeled by source term. A detailed investigation in terms of airflow and temperature distribution was carried out to figure out the motor temperature rise. The simulation results was validated with that of experimental results and found a good correlation. Thus a methodology is developed with which designer can select and package the motor in order to have minimum power consumption and maximum life.
Sen, Somnath
Implementation of Reinforcement Learning on Air Source Heat Pump Defrost Control for Full Electric Vehicles2018-01-11934/3/2018
Air source heat pumps as the heating system for full electric vehicles are drawing more and more attention in recent years. Despite the high energy efficiency, frost accumulation on the heat pump evaporator is one of the major challenges associated with air source heat pumps. The evaporator needs to be actively defrosted periodically and heat pump heating will be interrupted during defrosting process. Proper defrost control is needed to obtain high average heat pump energy efficiency. In this paper, a new method for generating air source heat pump defrost control policy using reinforcement learning is introduced. This model-free method has several advantages. It can automatically generate optimal defrost control policy instead of requiring manually determination of the control policy parameters and logics. More measurement results can be incorporated into the defrost control policy without too many changes in the reinforcement learning algorithm so that the control policy can be better optimized under wider range of working conditions. The learning features also enable the controller to adapt to the system differences and changes which are impossible to predict a priori when designing defrost control policy. The algorithm was validated using experimentally obtained heating capacity and COP data in frost growth cycle of a heat pump under different conditions. The results showed that reinforcement learning can be used to generate defrost control policy that optimizes energy consumption for various working conditions.
Zhu, Jingwei, Elbel, Stefan
Implementation of Electrified Air Conditioning on a Class 8 Long Haul Vehicle2018-01-00614/3/2018
Current methods employing electrified air conditioning (A/C) in class 8 long haul vehicles are hampered by insufficient capacity to cool the entire cabin both in sleeper mode and during normal on the road operation. A highly efficient single system solution is needed that meets cooling requirements under all operational modes without exceeding the power requirements that an onboard battery system can support. Results presented in this paper demonstrate the ability of an electrified A/C system to exceed cabin pulldown requirements within onboard electrical power availability while also meeting the low power draw requirements of sleeper mode operation. Results also demonstrate power electronics technology has advanced to the point that delivering ~5 kW of power at 48VDC (i.e. ~100A) can be accomplished in a reasonable sized package for commercial vehicle applications.
Vehr, Shawn W., Pistone, Kenneth, Gariety, Mark
Thermal Modeling of an Automotive HVAC Unit Using a Coupled POD and Flow Resistance Network Approach2018-01-00684/3/2018
In modern vehicle air conditioning concepts, the temperatures at the outlets of the Heating Ventilation and Air Conditioning (HVAC) unit are controlled using temperature sensors in combination with an Automatic Climate Control (ACC) system. A novel coupled Proper Orthogonal Decomposition (POD) and Flow Resistance Network (FRN) model approach is proposed to accurately predict the temperatures at the outlets of a HVAC unit for real-time model based control. The integral enthalpy flow rates at the outlets, which result from a complex mixing process in the mixing chamber of the HVAC unit, are approximated by a linear combination of orthonormal POD modes. A FRN is established to compute the volume flow rates at the outlets. By combining the classical FRN with the POD model the weighting coefficients for the POD modes can be determined from the volume flow rates estimated by the network model. This allows to reconstruct the enthalpy flow rates at the outlets and to calculate the outlet temperatures. To demonstrate the new method on a real HVAC geometry a test rig is built for the simultaneous measurement of volume flow rates and temperatures at the outlets. The experimental data is used to perform the POD, to calibrate the FRN and to evaluate the performance of the thermal HVAC model. The proposed method provides a systematic framework to accurately predict the outlet temperatures at low computational costs. It could be shown that the absolute temperature deviation between model and experiment at the outlets is less than 2 K. An inverse application of the model for climate control was demonstrated. Instead of using expensive temperature sensors, the model can be applied for model based ACC which reduces costs and facilitates control algorithms.
Christ, Paul, Sattelmayer, Thomas
HVAC System Bench Test Analysis for TXV Tuning2018-01-00704/3/2018
In today’s automotive industry, the A/C (Air-conditioning) system is emerging into a high level of technological growth to provide quick cooling, warm up and maintaining the air quality of the cabin during all-weather conditions. In HVAC system, TXV plays vital role by separating high side to low side of vapor compression refrigeration system. It also regulates the amount of refrigerant flow to the evaporator based on A/C system load. The HVAC system bench laboratory conducts the test at different system load conditions to evaluate the outputs from tests during initial development stage to select the right TXV in terms of capacity and Superheat set point for a given system. This process is critical in HVAC developmental activity, since mule cars will be equipped with selected TXV for initial assessment of the system performance. The TXV tuning is conducted in system bench lab using defined test load cases which is developed using combination of given input boundary conditions and tests were conducted based on that. In this paper, major focus is laid on understanding potential importance of each system parameter, identify bench test boundary conditions that are critical for TXV set point decision making and understand internal stakeholder’s requirement. The whole process started with conducting personal interviews with internal stakeholders and suppliers to collect raw voices of customers. The DFSS tools were used to capture internal customer voices and translate into technical measures to provide insight of the data required for TXV selection. Tools used such as voice affinity, HOQ, Pugh Matrix, and Function tree diagram etc. The raw voices from interviews are translated into most important voice and mapped with current process using HOQ approach. The main purpose of house of quality is to derive the measurable targets to meet customer requirement. This study helps us to reduce the number of physical testing by approx. 35% without affecting TXV selection process and use objective approach to study system parameters.
Sambandan, Saravanan, Valencia, Manuel, Khawaja, Aamir, S, Sathish Kumar
Optimization of the Engine Intake Air Temperature through the Air Conditioning Unit2018-01-09734/3/2018
In modern turbocharged internal combustion engines the cooling of the air after the compression stage is the standard technique to reduce temperature of the engine intake air aimed at improving cylinder filling (volumetric efficiency) and, therefore, overall global efficiency. At present, standard values for the intake air temperature are in the range 30-70°C, dependently on engine load, external air conditions and vehicle speed and the adoption of a dedicated cooling fluid operating at low temperatures (-10-0°C) is addressed as the most viable option to achieve an effective temperature reduction. This paper investigates a pilot engine set-up, featuring an evaporator on the intake line of a turbocharged diesel engine, tested on a high speed dynamometer bench: the evaporator was a part of an air refrigeration unit – the same used for cabin cooling - composed also by a compressor, a condenser and a thermostatic expansion valve. The effects of the undercooling of the charge air have been experimentally assessed in terms of fuel consumption and regulated emission reduction, evaluated on the most common engine operating points. Mechanical power needed by the compressor was obviously taken into account in order to assess the overall benefits. A fuel consumption reduction has been demonstrated in the order of 2.5% when the intake air subcooling is turned on. A benefit on the regulated emissions has been observed (NOx, PM). HC and CO behavior, on the contrary, deserves some more attention and involves engine control parameters (for instance, EGR rate) and combustion performances.
Di Battista, Davide, Vittorini, Diego, Di Bartolomeo, Marco, Cipollone, Roberto
Critical Cooling in Medical Devices – Part 2TBMG-287494/1/2018
The need for thermal management continues to increase in the medical industry. Active thermal management is critical for applications such as patient core temperature management, skin cooling, medical device cooling, and laboratory equipment cooling. Medical device designers need highly efficient and compact cooling systems that can be integrated into their systems, often with the option of battery power for mobility.
Radar Sensor SystemsTBMG-287864/1/2018
Kelvin Hughes London, UK +44 19 9280 5200
Q&A: Dr. Shannon Yee, Assistant Professor of Heat Transfer, Combustion, and Energy Systems at Georgia Institute of Technology, Atlanta, GATBMG-283312/1/2018
Using flexible conducting polymers and novel circuitry patterns printed on paper, researchers in Dr. Lee’s laboratory have demonstrated proof-of-concept wearable thermoelectric generators that can harvest energy from body heat to power simple biosensors for measuring heart rate, respiration, or other factors.
Effect of Magnetic Nanorefrigerant on Electric Vehicle2017-01-222210/8/2017
The ever increasing popularity of electric vehicles and higher requirement on safety and comfort has led heat pump air conditioning system indispensable in electric vehicle. Many studies have shown that the addition of nano particles contributes to great improvement on thermal conductivity than that of conventional refrigerants. Therefore, the application of the magnetic nanorefrigerant in heat pump air conditioning system has massive potential to heighten the heat transfer efficiency. This paper aims at studying the magnetic nanorefrigerant comprised of the magnetic nano powder Fe3O4 and refrigerant R134a. According to the relevant theoretical analyses and empirical formula, the heat transfer coefficient, density, viscosity, and other physical parameters are calculated approximately. In the heat pump air conditioning system of a certain type of electric vehicle, the special working condition parameters are selected to carry out calculation analysis with numerical analysis software. The results show that the heat exchange amount of this nanorefrigerant is 21.23% higher than the pure refrigerant R134a and increases with the volume fraction of the nano particles. Moreover, after adding Fe3O4 nano materials to the heat pump air conditioning system, the efficiency of this system has been increased by 8.6%. So the conclusion can be drawn that appliance of the nano-refrigerant in electric vehicle is both effective and feasible.
Liu, ZhenYang, Wang, Xihui
Aircraft Ground Air Conditioning Service ConnectionAS4262B (Current)10/3/2017
This SAE Aerospace Standard (AS) defines interface configurations for the ground air conditioning service connection on commercial transport aircraft. In addition, it defines the clearances required to accommodate the connection of ground air conditioning hose couplings. Two types of service connections are included. The Type A connection (Figure 1) is a slotted ring with integral locking pads and is comparable to the MS33562 connection. The Type B connection (Figure 2) is a flanged tube with external locking lugs (Figure 3). The Type B connection has the same interface dimensional requirements as the Type A connection.
AGE-3 Aircraft Ground Support Equipment Committee
Digital Aeroacoustics Design Method of Climate Systems for Improved Cabin Comfort2017-01-17876/5/2017
Over the past decades, interior noise from wind noise or engine noise have been significantly reduced by leveraging improvements of both the overall vehicle design and of sound package. Consequently, noise sources originating from HVAC systems (Heat Ventilation and Air Conditioning), fans or exhaust systems are becoming more relevant for perceived quality and passenger comfort. This study focuses on HVAC systems and discusses a Flow-Induced Noise Detection Contributions (FIND Contributions) numerical method enabling the identification of the flow-induced noise sources inside and around HVAC systems. This methodology is based on the post-processing of unsteady flow results obtained using Lattice Boltzmann based Method (LBM) Computational Fluid Dynamics (CFD) simulations combined with LBM-simulated Acoustic Transfer Functions (ATF) between the position of the sources inside the system and the passenger’s ears. It provides an approximation of the contribution of each noise source to the passenger’s ear locations. By identifying and quantifying noise sources, this method guides engineers at treating the main sources in confined systems, usually a daunting task experimentally. In a first part, the accuracy of this numerical approach is investigated by comparing predicted aeroacoustics results to measured data: in a first step for a simple lateral duct with vent; in a second step for a HVAC unit in fresh air ventilation mode. In a second part, the Flow-Induced Noise Detection Contributions method is used to highlight the location and intensity of the various noise sources for the different operating conditions. In the third and last part, limited modifications are made to the HVAC system geometry within design constraints, and LBM simulations are performed on the modified design to numerically assess the reduction of the noise levels.
Biermann, Jan, Mann, Adrien, Neuhierl, Barbara, Kim, Min-Suk
The Effect of HVAC Buffeting on Automatic Speech Recognition Systems2017-01-17816/5/2017
The design and operation of a vehicle’s heating, ventilation, and air conditioning (HVAC) system has great impact on the performance of the vehicle’s Automatic Speech Recognition (ASR) and Hands-Free Communication (HFC) system. HVAC noise provides high amplitudes of broadband frequency content that affects the signal to noise ratio (SNR) within the vehicle cabin, and works to mask the user’s speech. But what’s less obvious is that when the airflow from the panel vents or defroster openings can be directed toward the vehicle microphone, a mechanical “buffeting” phenomenon occurs on the microphone’s diaphragm that distresses the ASR system beyond its ability to interpret the user’s voice. The airflow velocity can be strong enough that a simple windscreen on the microphone is not enough to eliminate the problem. Minimizing this buffeting effect is a vital key to building a vehicle that meets the customer’s expectations for ASR and HFC performance. Systems design principles must be applied to ensure that the placement of the microphone and vents, HVAC airflow management, and active noise reduction solutions are all designed in concert to reduce exposure to the problem. In this paper, we examine the objective effect that HVAC buffeting has on the ASR system, above and beyond the masking noise provided when the airflow is directed away from the microphone. We discuss vent and microphone placement that can contribute to the error state, and propose design guidelines or active solutions that can help reduce the occurrence and impact of HVAC buffeting.
Wheeler, Joshua
Audio Synthesis and Sound Quality of Automotive Air-Conditioning Systems2017-01-18876/5/2017
While electric and hybrid vehicles are becoming increasingly common, the issue of engine noise is becoming less important, because it does not dominate the overall noise perceived in the passenger compartment in such vehicles anymore. However, at the same time, other sound sources such as air conditioning, start to emerge, which can also cause annoyance. The CEVAS project, involving VALEO, CETIM, University of Technology of Compiègne, ESI GROUP and GENESIS, deals with the acoustic simulation and perception of automotive air-conditioning (HVAC) and electric battery cooling (BTM) systems. While the other partners focused their work on the aeroacoustic characterization, modeling and simulation, GENESIS’ part in the project is dedicated to HVAC sound synthesis and perception. In order to do the synthesis of the acoustic spectra provided by the partners of the project, an additive model was used. Its ability to reliably reproduce sound recordings was addressed through a listening experiment, which also helped in defining the necessary resolution of the input spectra in order to produce convincing sounds. Finally, various HVAC sounds, including different models, operating modes and airflow rates, were assessed by means of a psychoacoustic method involving two listening experiments: a verbalization task, and a semantic differential task. The results were statistically analyzed and a robust sound quality model based on loudness and tonality metrics was proposed.
Minard, Antoine, Lambourg, Christophe, Boussard, Patrick, Cheriaux, Olivier
Interior Noise and Vibration Reduction of BRT - Premium Segment Bus2017-01-18666/5/2017
Urbanisation has led to an increased need for mobility in public transportation. Sensing the unfolding worrisome scenario, many countries have taken up different mass rapid transit solutions to alleviate the problem and restore the free flowing traffic. BRT should have been the logical choice particularly considering the lower capital costs involved and faster implementation. Comprehensibly the expectations of this class of vehicles will be high in term of quality and comfort to the passengers. Level of vibration and noise is an important indicator to evaluate vehicle's ride comfort. The challenges are to design the high powered Powertrain and Air Conditioning system nonetheless low interior noise, vibration and harshness correspondents to personal cars. This paper is an invention of, development work done in interior noise refinement of a bus. A prototype bus manufactured to meet all the requirement of BRT - premium segment urban bus. The prototype was almost meeting the entire required specifications, excluding interior noise and vibrations. The rear zone of the interior was the major concern of NVH levels, which demands to carry out the root cause analysis. There were various structure-borne and air-borne sources contributing to increase in NVH levels. Design and development iterations were conducted on the vehicle to achieve the well significant noise and vibration reduction and increased comfort to the passengers.
Jawale, Pradeep, Karanth, Nagesh
Upgrading a Large Reverberation Room to Meet AHRI 2202017-01-18966/5/2017
A large reverberation room of approximately 310 m3 (11,000 ft3) used in the air conditioning, heating and refrigeration industry, was in need of improvements to meet the updated requirements of the American Heating and Refrigeration Institute (AHRI) Standard 220. In addition, it was desired to extend the measurement qualification of the room down to the 63 Hz octave band. The initial qualification test results showed that the room did not qualify for the extended low frequency range and also had some irregularities in the 100 Hz third octave band. This paper reports the results of a three-part investigation to correct reverberation room response irregularities in the 100 Hz third octave band, to establish performance that qualifies relative to the most recent standard, and to determine and integrate the means by which its qualification could be extended down to the frequency bands of 50, 63, and 80Hz.
Kolano, Richard A., Brown, Darren J.
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