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2015-06-15
Technical Paper
2015-01-2249
Saad Bennouna, Said Naji, Olivier Cheriaux, Solene Moreau, Boureima Ouedraogo, Jean Michel Ville
Passengers’ thermal comfort inside car cabin is mainly provided by the heating ventilation and air conditioning system (HVAC). The main part of HVAC modules is placed under the dash board. An HVAC module is a compact system composed of various elements which are subject to airflow. The interaction between airflow and these in-duct elements generates noise inside car cabin. Furthermore, the blower used to blow air inside the cabin must overcome the pressure generated by HVAC elements. Noise is created and its level is linked to flow and pressure. HVAC noise is an important issue for car makers and automotive suppliers wishing to reach passengers’ satisfaction. Furthermore thermal-engine cars are more and more silent. Also hybrid and electric car sells are expanding around the world. HVAC noise became a main issue for automotive actors. In order to reduce its HVAC noises, Valeo and partners worked to develop several methods.
2015-06-15
Technical Paper
2015-01-2323
Abdelhakim Aissaoui, Ravindra S Tupake, Vilas Bijwe, Mohammed Meskine, Franck Perot, Alain Belanger, Rohit J Vaidya
F or the automotive industry, acoustic comfort is of increasing importance and changes in the market make the HVAC system noise quality a question to be addressed as early as possible during the vehicle development process. On one hand, the so-called traditional sources of annoyance such as engine, road-tires contact, exhaust systems and wind-noise have been significantly reduced for most traditional combustion engine vehicles. On the other hand, the rapid expansion of hybrid and electric vehicles and idling stop systems increases the importance of sources such as HVAC systems considered in the past as secondary. At high mass flow rate, the flow-induced contribution from the ducts and registers is the main source of noise in the mid to high frequency ranges and is more important than the HVAC structure borne and blower engine contributions.
2015-06-15
Technical Paper
2015-01-2271
Yong Du Jun, Bong Hyun Park, Kang Seok Seo, Tae Hyun Kim, Myoung Jae Chae
An objective measure is proposed for seat riding comfort evaluation under low frequency (0~2 Hz) vibratory conditions which represents typical roll and pitch motions of driving motor vehicles. The related feeling due to this low frequency vehicle motion is termed ‘hold feeling’ because the seated body may tend to deviate from the defined seating position under such vehicle motion inputs. In the present study, dynamic pressure distribution measurements have been performed with a roll motion simulator at different frequencies between 0.3 and 1.0 Hz, to monitor the interface pressure change behavior of the seat-subject body. Temporal changes in body pressure in terms of the magnitude and the representative locations, and the time delay in pressure change at different regions of the seat are identified to be useful parameters for describing the subject's responses and with the subjective test results.
2015-06-15
Technical Paper
2015-01-2210
Quan Wan
Five parameters are often used in acoustic modeling of porous absorption material, which are air flow resistivity σ, porosity φ, tortuosity α∞, viscous characteristic lengths Λ and thermal characteristic length Λ’. These parameters are not easy to be directly measured with high precision, especially the latter three parameters. FOAM-X is the software capable of identifying indirectly these parameters from impedance tube test results by virtue of Johnson-Champoux-Allard model, so becomes increasingly popular. However, its stability of parameter identification is rarely reported. This paper studies the factors to disturb the stability of FOAM-X on those porous absorption materials generally applied in vehicle interior trim (pure PET fiber, shoddy, PP/PET double-component fiber), such as the number of known parameters in advance, the frequency range, the vacuum bulk density, and so on.
2015-06-15
Technical Paper
2015-01-2273
Curtis Jones, Zhengyu Liu, Suhas Venkatappa, James Hurd
Abstract This paper presents the methodology of predicting vehicle level automotive air-handling system air-rush noise sound quality (SQ) using the sub-system level measurement. Measurement setup in both vehicle level and sub-system levels are described. To assess the air-rush noise SQ, both 1/3 octave band sound pressure level (SPL) and overall Zwicker's loudness are used. The “Sound Quality Correlation Functions (SQCF)” between sub-system level and vehicle level are developed for the specified climate control modes and vehicle segment defined by J.D. Power & Associates, while the Zwicker's loudness is calculated using the un-weighted predicted 1/3 octave band SPL. The predicting models are demonstrated in very good agreement with the measured data. The methodology is applied to the development of sub-system SQ requirement for upfront delivery of the optimum design to meet global customer satisfaction
2015-06-15
Technical Paper
2015-01-2303
Katherine Tao, Alan Parrett, David Nielubowicz
The headliner system in a vehicle is an important element in vehicle noise control. In order to predict the performance of the headliner, it is necessary to develop an understanding of the substrate performance, the effect of air gaps, and the contribution from any acoustic pads in the system. Current Statistical Energy Analysis (SEA) models for predicting absorption performance of acoustic absorbers are based on material Biot properties. However, the resources for material Biot property testing are limited and cost is high. In this paper, modeling parameters for the headliner substrate are identified from a set of standard absorption measurements on substrates, using curve fitting and optimization techniques. The parameters are then used together with thickness/design information in a SEA model to predict the vehicle headliner system absorption performance.
2015-06-15
Technical Paper
2015-01-2339
Márcio Calçada, Alan Parrett
Sound absorption materials can be key elements for mass-efficient vehicle noise control. They are utilized at multiple locations in the interior and one of the most important areas is the roof. At this location, the acoustic treatment typically comprises a headliner and an air gap up to body sheet metal. The performance requirement for such a vehicle subsystem is normally a sound absorption curve. Based on headliner geometry and construction, the sound absorption curve shape can be adjusted to increase absorption in certain frequency ranges. In this paper an overall absorption metric is developed to relate design parameters to an absorption curve shape which results in improved in-vehicle performance. This metric is based on sound absorption coefficient and articulation index. Johnson-Champoux-Allard equivalent fluid model and diffuse field equations are used. The results are validated using impedance tube measurements.
2015-06-15
Technical Paper
2015-01-2235
Arnaud Caillet, Denis Blanchet
Abstract The need in the automotive industry to understand the physical behavior of trims used in a vehicle is high. The PEM (poro-elastic method) was developed to permit an explicit representation of the trims in the FEM full vehicle models and to give tools to diagnose the effect of the trims and test design changes (porous material property, geometry, etc.,). During the last decade, the evolution of software and hardware has allowed the creation of models with highly detailed trim description (porous material using Biot parameters, plastic trims, etc.,). These models can provide good correlation up to 400Hz compared to measurements in contrast to classical NSM (Non Structural Mass) methodology which shows limitations.
2015-06-15
Technical Paper
2015-01-2266
Andrzej Pietrzyk
Abstract Several of the exterior noise sources existing around a vehicle can cause airborne noise issues at relatively low frequencies. SEA, traditionally used for airborne sound issues is not suitable for the frequency range of interest. Finite Element analysis has been used. Handling of the non-reflecting condition on the outer boundary of the exterior cavity is an issue. Recently, advances have been made in several commercially available codes, which made the analysis practical. Including the poro-elastic material model for foam-based carpets is also becoming practically possible. The purpose of the current study is to investigate the practical applications of those new developments against test data, and to estimate the feasibility of using these procedures in the vehicle development projects. Measurements were carried out in a new semi-anechoic chamber at Volvo Cars.
2015-06-15
Journal Article
2015-01-2276
Zhengyu Liu, Donald Wozniak, Manfred Koberstein, Curtis Jones, Jan Xu, Suhas Venkatappa
Abstract Refrigerant flow-induced gurgling noise is perceived in automotive refrigerant systems. In this study, the condition of the gurgling generation is investigated at the vehicle level and the fundamental root cause is identified as the two-phase refrigerant flow entering the TXV for system equipped with variable displacement compressors. By conducting literature reviews, the acoustic characteristics of the flow patterns and the parameters affecting the flow regimes in horizontal and vertical tubes are summarized. Then the gurgling mechanism is explained as the intermittent flow is developed at the evaporator inlet. In the end, the improved and feasible design for avoiding the intermittent flow (slug, plug or churn flow) or minimizing its formation is proposed and verified in refrigerant subsystem (RSS) level. Finally, the guidelines for the attenuation and suppression of the gurgle are provided.
2015-06-15
Journal Article
2015-01-2275
Manfred Koberstein, Zhengyu Liu, Curtis Jones, Suhas Venkatappa
Abstract In the thermal expansion valve (TXV) refrigerant system, transient high-pitched whistle around 6.18 kHz is often perceived following air-conditioning (A/C) compressor engagements when driving at higher vehicle speed or during vehicle acceleration, especially when system equipped with the high-efficiency compressor or variable displacement compressor. The objectives of this paper are to conduct the noise source identification, investigate the key factors affecting the whistle excitation, and understand the mechanism of the whistle generation. The mechanism is hypothesized that the whistle is generated from the flow/acoustic excitation of the turbulent flow past the shallow cavity, reinforced by the acoustic/structural coupling between the tube structural and the transverse acoustic modes, and then transmitted to evaporator. To verify the mechanism, the transverse acoustic mode frequency is calculated and it is coincided to the one from measurement.
2015-05-27
Article
A second coolant loop in a Fiat Grande Punto prototype provides liquid cooling of the A/C condenser and turbo intercooler, with potential for including air coolers for engine and transmission oil, power steering fluid and other heat exchangers. Engineers measured a 5% improvement in fuel economy during A/C-on operation during NEDC testing.
2015-05-26
Standard
J1647_201505
This SAE Recommended Practice provides test methods and requirements to evaluate the suitability of plastic optical materials for possible use in discharge forward lighting (DFL) devices in motor vehicles. These materials are typically used for lenses and reflectors. Separate testing is required for each combination of material, industrial coating, DFL light source, and device focal length. The tests are intended to determine physical and optical characteristics of the materials and coatings. Performance expectations of finished assemblies, including plastic components, are to be based on tests for lighting devices, as specified in SAE Standards and Recommended Practices for motor vehicle lighting equipment. Optical components exposed to weathering should also be subject to SAE J576.
2015-05-19
WIP Standard
J2944_201505
This Recommended Practice, Operational Definitions of Driving Performance Measures and Statistics, provides functional definitions of and guidance for performance measures and statistics concerned with driving on roadways. As a consequence, measurements and statistics will be calculated and reported in a consistent manner in SAE and ISO standards, journal articles proceedings papers, technical reports, and presentations so that the procedures and results can be more readily compared. Only measures and statistics pertaining to driver/vehicle responses that affect the lateral and longitudinal positioning of a road vehicle are currently provided in this document. Measures and statistics covering other aspects of driving performance may be included in future editions. For eye glance-related measures and statistics, see SAE J2396 (Society of Automotive Engineers, 2007) and ISO 15007-1 (International Standards Organization, 2002).
2015-05-08
WIP Standard
J2365
This SAE Recommended Practice applies to both Original Equipment Manufacturer (OEM) and aftermarket route-guidance and navigation system functions for passenger vehicles. This recommended practice provides a method for calculating the time required to complete navigation system-related tasks. These estimates may be used as an aid to assess the safety and usability of alternative navigation and route guidance system interfaces to assist in their design. This document does not consider voice-activated controls, voice output from the navigation system, communication between the driver and others, or passenger operation.
2015-05-07
Standard
ARP4156C
This document defines the method for voltage identification by the use of color-coded insulators at the base of the lamps. Table 1 shows the design volts and corresponding insulator colors. The part numbers shown are for example purposes only, as an option. Insulator colors are to be easily distinguishable as green, yellow, red, and white. Additional colors may be added by a revision process as required.
2015-05-07
Standard
J2842_201505
The intent of this standard is to establish a framework to assure that all evaporators for R-744, R-1234yf, and R-445A mobile air conditioning (MAC) systems meet appropriate testing and labeling requirements. SAE J639 requires vehicle manufacturers to perform assessments to minimize reasonable risks in production MAC systems. The evaporator (as designed and manufactured) shall be part of that risk assessment and it is the responsibility of the vehicle manufacturer to assure all relevant aspects of the evaporator are included. It is the responsibility of all vehicle or evaporator manufacturers to comply with the standards of this document at a minimum. (Substitution of specific test procedures by vehicle manufactures that correlate well to field return data is acceptable.) As appropriate, this standard can be used as a guide to support risk assessments.
2015-05-07
Standard
J1757/1_201505
The scope of this SAE Standard is to provide methods to determine display optical performance in all typical automotive ambient light illumination - with focus on High Ambient Contrast Ratio, which is critical for display legibility in a sunshine environment. It covers indoor measurements and simulated outdoor lighting. It is not the scope of this document to set threshold values for automotive compliance. However some recommended values are presented for reference.
2015-05-05
WIP Standard
J3099
Presents the seating accommodation model used to determine seat track length for accommodation in design.
2015-05-04
WIP Standard
J576
This SAE Recommended Practice provides test methods and requirements to evaluate the suitability of plastic materials intended for optical applications in motor vehicles. The tests are intended to determine physical and optical characteristics of the material only. Performance expectations of finished assemblies, including plastic components, are to be based on tests for lighting devices, as specified in SAE Standards and Recommended Practices for motor vehicle lighting equipment. Field experience has shown that plastic materials meeting the requirements of this document and molded in accordance with good molding practices will produce durable lighting devices.
2015-05-01
Journal Article
2015-01-9017
Johannes Wurm, Matthias Fitl, Michael Gumpesberger, Esa Väisänen, Christoph Hochenauer
Abstract Nowadays, investigating underhood airflow by using numerical simulation is a standard task in the development process of passenger cars and commercial vehicles. Numerous publications exist which deal with simulating the airflow through the engine compartment of road vehicles. However, hardly anything can be found which deals with off-road vehicles and nothing exists which focuses on snowmobiles. In the presented paper the airflow and the thermal conditions inside the engine compartment of a snowmobile are investigated by the usage of computational fluid dynamics (CFD) as well as experimental methods. Field tests at arctic conditions have been conducted on a serial snowmobile to measure temperatures inside the compartment and to gain realistic boundary conditions for the numerical simulation. Thermocouples (type K) were attached under the hood to measure exhaust, air, coolant and surface temperatures of several components at previously defined load cases.
2015-04-30
Article
A key to connecting smart phones to third-party software developers' mind-boggling array of mobile applications is the application programming interface. The husband and wife team behind Road Rules discuss discuss a range of topics from car hacking that is mostly overblown to apps that use more car data.
2015-04-30
WIP Standard
3098
This SAE Standard specifies the minimum performance recommendation for spark plugs intended for use in various internal combustion engines including Automotive, Marine, Motorcycle and Utility engine applications. This standard is not intended to supply information for spark plugs used in aircraft applications of any type.
2015-04-24
Article
Car buyers want a human-machine interface that lets them bring in personal devices and perform all kinds of tasks whenever they want, and they don’t want to have to read a manual or spend time learning how to manage their many options. Panelists grappled with solutions to this vexing challenge during a 2015 SAE World Congress panel.
2015-04-23
WIP Standard
J3096
This SAE Recommended Practice is being developed primarily for passenger car and truck application, but may be used in marine, industrial, and similar applications.
2015-04-21
Standard
J51_201504
This SAE Standard covers reinforced hose, or hose assemblies, intended for conducting liquid and gaseous dichlorodifluoromethane (refrigerant 12) in automotive air-conditioning systems. The hose shall be designed to minimize permeation of refrigerant 12 and contamination of the system and to be serviceable over a temperature range of -30 to 120 °C (-22 to 248 °F). Specific construction details are to be agreed upon between user and supplier. NOTE— SAE J2064 is the Standard for refrigerant 134a hose. For refrigerant 134a use, refer to SAE J2064
2015-04-17
Article
The new 8.4-in XGA developed by NLT Technologies is an amorphous-silicon thin-film-transistor LCD module with a "Wet & Glove" projected capacitive (PCAP) touch sensor bonded to the front.
2015-04-14
Collection
Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance and quality of climate control are both critical to customer satisfaction. The system has strong design interaction with other vehicle systems, while its primary objective is to deliver thermal comfort and occupant safety with low energy consumption. Localized Comfort, Secondary Fluids, Air Quality, Controls, System Sizing and HVAC consumer interface are just a few of the recent advances.
2015-04-14
Collection
This technical paper collection focuses on state of the art simulation technologies for modeling thermal systems and their application in the development and optimization of vehicle thermal management and fuel economy. The papers in this collection will range from empirical, 1D modeling methods to three dimensional CFD models as well as coupled methods.
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