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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
2015-01-2235
Arnaud Caillet, Denis Blanchet
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…). During the last decade, the evolution on software and hardware sides have allowed to create models with a highly detailed trim description (Porous material using the Biot parameters, plastic trims...). These models can provide a good correlation up to 400Hz against the measurements compared to the classical NSM methodology which shows limitations.
2015-06-15
Technical Paper
2015-01-2266
Andrzej Pietrzyk
Several of the exterior noise sources existing around a vehicle can cause airborne noise issues at relatively low frequencies. One of them is exhaust pipe orifice noise. Traditional methods for handling airborne noise in vehicles, such as SEA, are not suitable for the frequency range of interest. Finite Element analysis has been used, but it often ends up with very heavy runs if semi-infinite acoustic elements are used at the outer boundary as the solution has to be direct instead of modal in this case. There are, however, some softwares that can handle this calculation relatively efficiently. One of the primary choices could be FFT&Actran. However, recently, a similar capability has been developed in MSC Nastran. Also, the calculations involving the free field impedance conditions have been made extremely efficient in CDH/AMLS. Including the poro-elastic material model for foam-based carpets is also becoming practically possible.
2015-06-15
Technical Paper
2015-01-2273
Curtis Jones, Zhengyu Liu, James Hurd III, Suhas Venkatappa
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 Transfer Functions (SQTF)" 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 SPLs by the Matlab-based program. The predicting models are demonstrated in a fairly 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
2015-01-2271
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
2015-01-2276
Zhengyu Liu, Donald Wozniak, Manfred Koberstein, Curtis Jones, Jan Xu, Suhas Venkatappa
Refrigerant flow-induced gurgling noise is perceived in automotive refrigerant systems which equipped with variable displacement compressors. In this study, the condition of the gurgling generation is investigated in vehicle level and the fundamental root cause is identified as the two-phase refrigerant flow entering the TXV. By conducting literature review, the acoustic characteristics of the flow patterns and the parameters affecting the flow regimes in horizontal and vertical tubes are summarized, and then the gurgling mechanism is explained as that 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 sub-system (RSS) level. Finally, the guidelines for the attenuation and suppression of the gurgle are provided.
2015-06-15
Technical Paper
2015-01-2275
Manfred Koberstein, Zhengyu Liu, Curtis Jones, Suhas Venkatappa
In the thermal expansion valve (TXV) refrigerant system, transient high-pitched whistle at 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.
2015-06-15
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
2015-01-2303
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.
2015-05-01
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.
2015-04-24
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.
2015-04-14
Collection
Proper thermal management can significantly contribute to overall system energy efficiency. This technical paper collection highlights the latest developments in thermal management energy efficiency.
2015-04-14
Collection
This technical paper collection considers modeling (zero-D, 1D, 2D, 3D CFD) and experimental papers on: combustion chamber, systems (lubrication, cooling, fuel, EGR); components (oil pumps, coolant pump, fuel injectors, compressors, turbines, turbochargers, torque converters, gear box, fans, bearings, valves, ports, manifolds, turbine housing); heat exchangers (radiators, oil coolers); aftertreatment (SCR, DOC, DOF, exhaust gas cooling); battery cooling (HEV, EV, motor/generator) and controls (passive and active).
2015-04-14
WIP Standard
J2944
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).
2015-04-14
Technical Paper
2015-01-1122
Kengo Yabe, Toru Inagaki, Takashi Kondo
Abstract Seat vibration when a vehicle is idling or in motion is an issue in automobile development. In order to reduce this vibration, dynamic damper or inertia mass is widely used. These countermeasures increases vehicle's weight and causes bad fuel-efficiency. Some new ways to reduce the vibration without weight increase are needed. One of that is the floating seat. Seat vibration has been reduced by controlling seat resonance frequencies. In order to control resonance frequency, the structures of the seat-mounting unit are replaced with floating structures using rubber bushings. It was demonstrated that partially replacing the mounting unit with floating structures makes it possible to control the resonance frequencies of the entire seat. The issue of balancing vibration reduction with strength and durability and crash safety performance caused by the fitting of rubber bushings to the seat-mounting unit was addressed using stopper structures optimized for each type of input.
2015-04-14
Technical Paper
2015-01-1189
Satyam Panchal, Scott Mathewson, Roydon Fraser, Richard Culham, Michael Fowler
Abstract A major challenge in the development of the next generation electric and hybrid electric vehicle (EV and HEV) technology is the control and management of heat generation and operating temperatures. Vehicle performance, reliability and ultimately consumer market adoption are integrally dependent on successful battery thermal management designs. In addition to this, crucial to thermal modeling is accurate thermo-physical property input. Therefore, to design a thermal management system and for thermal modeling, a designer must study the thermal characteristics of batteries. This work presents a purely experimental thermal characterization of thermo-physical properties of a lithium-ion battery utilizing a promising electrode material, LiFePO4, in a prismatic pouch configuration. In this research, the thermal resistance and corresponding thermal conductivity of prismatic battery materials is evaluated.
2015-04-14
Journal Article
2015-01-1184
Satyam Panchal, Scott Mathewson, Roydon Fraser, Richard Culham, Michael Fowler
Abstract The performance, life cycle cost, and safety of electric and hybrid electric vehicles (EVs and HEVs) depend strongly on their energy storage system. Advanced batteries such as lithium-ion (Li-ion) polymer batteries are quite viable options for storing energy in EVs and HEVs. In addition, thermal management is essential for achieving the desired performance and life cycle from a particular battery. Therefore, to design a thermal management system, a designer must study the thermal characteristics of batteries. The thermal characteristics that are needed include the surface temperature distribution, heat flux, and the heat generation from batteries under various charge/discharge profiles. Therefore, in the first part of the research, surface temperature distribution from a lithium-ion pouch cell (20Ah capacity) is studied under different discharge rates of 1C, 2C, 3C, and 4C.
2015-04-14
Technical Paper
2015-01-1334
Shreyas Shingavi, Pankaj Bhirud, Abhishek Ranjan
Abstract Safety and Comfort are the core requirements of the automotive seating systems. Number of the occupants, determines type of the seating system requirement. The second row seat often needs to fold and slide, to allow the passenger to enter inside the car. Folding second row seat will also allow accommodating larger length cargo. The over folding of seat is controlled by hard stop mechanism. The hard stop mechanism generally consists of the seat arm stopper at back seat and hard stop located at base of the seat. These stoppers will limit the further motion of back seat. The folding speed of back seat is governed by various factors e.g. adjacent seat foam/structure friction, location, structural mass of seat etc. The scope of the paper is to evaluate various folding speeds of the back seat. Its effects are evaluated for the stresses and fatigue life of the hard stop components.
2015-04-14
Journal Article
2015-01-0671
Saeed Jahangirian, Ashutosh Srivastava, Seyed Alireza Hosseini, Steven Ballard, Naiqiang Wu, John Kiedaisch
Abstract Durability assessments of modern engines often require accurate modeling of thermal stresses in critical regions such as cylinder head firedecks under severe cyclic thermal loading conditions. A new methodology has been developed and experimentally validated in which transient temperature distributions on cylinder head, crankcase and other components are determined using a Conjugate Heat Transfer (CHT) CFD model and a thermal finite element analysis solution. In the first stage, cycle-averaged gas side boundary conditions are calculated from heat transfer modeling in a transient in-cylinder simulation. In the second stage, a steady-state CHT-CFD analysis of the full engine block is performed. Volume temperatures and surface heat transfer data are subsequently transferred to a thermal finite element model and steady state solutions are obtained which are validated against CFD and experimental results.
2015-04-14
Technical Paper
2015-01-0717
Anindya Deb, G S Venkatesh, Ashok Mache
Abstract The usage of lightweight materials such as plastics and their derivatives continues to increase in automobiles driven by the urgency for weight reduction. For structural performance, body components such as A-pillar or B-pillar trim, instrument panel, etc. have to meet various requirements including resistance to penetration and energy absorption capability under impact indentation. A range of plain and reinforced thermoplastics and thermosetting plastics has been considered in the present study in the form of plates which are subject to low velocity perforation in a drop-weight impact testing set-up with a rigid cylindrical indenter fitted to a tup. The tested plates are made of polypropylene (PP), nanoclay-reinforced PP of various percentages of nanoclay content, wood-PP composites of different volume fractions of wood fiber, a jute-polyester composite, and a hybrid jute-polyester reinforced with steel.
2015-04-14
Technical Paper
2015-01-0505
Miguel Angel Reyes Belmonte, Colin D. Copeland, Drummond Hislop, George Hopkins, Adrian Schmieder, Scott Bredda, Sam Akehurst
Abstract Pressure and temperature levels within a modern internal combustion engine cylinder have been pushing to the limits of traditional materials and design. These operative conditions are due to the stringent emission and fuel economy standards that are forcing automotive engineers to develop engines with much higher power densities. Thus, downsized, turbocharged engines are an important technology to meet the future demands on transport efficiency. It is well known that within downsized turbocharged gasoline engines, thermal management becomes a vital issue for durability and combustion stability. In order to contribute to the understanding of engine thermal management, a conjugate heat transfer analysis of a downsized gasoline piston engine has been performed. The intent was to study the design possibilities afforded by the use of the Selective Laser Melting (SLM) additive manufacturing process.
2015-04-14
Technical Paper
2015-01-0613
Donghong Ning, James Coyte, Hai Huang, Haiping Du, Weihua Li
Abstract This paper presents a study on experimental vibration simulation using a multiple-DOF motion platform for heavy duty vehicle seat suspension test. The platform is designed to have 6-DOF with the advantages of high force-to-weight ratio, high dexterity and high position accuracy. It can simulate vehicle vibrations in the x, y and z translational axis and in the roll pitch and yaw axis rotation. To use this platform to emulate the real vibration measured from vehicle seat base under real operation for vehicle seat suspension test in lab, an Inertial Measurement Unit (IMU) is applied to collect the acceleration data from a real vehicle. An estimation algorithm is developed to estimate the displacement from the measured acceleration. The estimated displacement is then used to calculate the length of each leg of the platform so that the platform can generate the motion similar to the measured one.
2015-04-14
Journal Article
2015-01-1379
Hideki Matsumura, Shinichiro Itoh, Kenichi Ando
Abstract Lithium-ion cells are being used in an increasing number of electric and hybrid vehicles. Both of these vehicle types contain many cells. Despite various safety measures, however, there are still reports of accidents involving abnormal heat, smoke, and fire caused by thermal runaway in the cells. If thermal runaway in one cell triggers that of another and thus causes thermal runaway propagation, this can lead to rupture of the battery pack, car fire, or other serious accidents. This study is aimed to ensure the safety of vehicles with lithium-ion cells by clarifying such accident risks, and so we investigated the process of thermal runaway propagation. In the experiment, we created a battery module made of seven laminate-type cells tightly stacked one on another. Then, we induced thermal runaway in one of the cells, measured the surface temperatures of the cells, and collected video data as the process developed. As a result, all of the seven cells underwent thermal runaway.
2015-04-14
Technical Paper
2015-01-1230
Ahmed Imtiaz Uddin, Jerry Ku
Abstract It is well known that thermal management is a key factor in design and performance analysis of Lithium-ion (Li-ion) battery, which is widely adopted for hybrid and electric vehicles. In this paper, an air cooled battery thermal management system design has been proposed and analyzed for mild hybrid vehicle application. Computational Fluid Dynamics (CFD) analysis was performed using CD-adapco's STAR-CCM+ solver and Battery Simulation Module (BMS) application to predict the temperature distribution within a module comprised of twelve 40Ah Superior Lithium Polymer Battery (SLPB) cells connected in series. The cells are cooled by air through aluminum cooling plate sandwiched in-between every pair of cells. The cooling plate has extended the cooling surface area exposed to cooling air flow. Cell level electrical and thermal simulation results were validated against experimental measurements.
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