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2015-01-14
Technical Paper
2015-26-0125
Sambhaji Keshaw Jaybhay, Sudhakara Naidu, Prasanna Nagarhalli, J Saiprasad
LCV AC buses market is rapidly growing up in India; major requirement is for staff pick-up and drop, school applications and private fleet owners. The air-conditioning system is typically mounted on bus roof top and located laterally and longitudinally at center. It is an easiest and most feasible way to package air conditioning system to cater the large passenger space (32 to 40seats) with the conditioned air. This makes air conditioning duct design simple and commercially viable. Most of the LCV buses are with front engine configuration which adds more heat and noise to Driver and passenger compartment, this demands for isolation of Driver’s area from passenger area by means of partition in between. Without partition engine noise is more dominant in passenger area, but in case of with partition, blower noise of roof mounted AC system is more perceivable in passenger area.
2015-01-14
Technical Paper
2015-26-0127
Gaurav Paliwal, Naveen Sukumar, Umashanker Gupta, Saurav Roy, Hemantkumar Rathi
The main emphasis for a Commercial vehicle design which was focused on fuel-economy and durability does not fulfill the increasing customer expectations anymore. Commercial vehicle designers need to focus on other vehicle aspects such as steering, ride comfort, NVH, braking, ergonomics and aesthetics in order to provide car like perception to truck, bus drivers and passengers during long distance drives. Powertrain mounting system must perform many functions. First and foremost, the mounting system must maintain & control the overall motion of the powertrain, to restrict its envelope reasonably, thereby avoiding damage to any vehicle component from the potential impact. This requires the mount to be stiff. Second the mount must provide good vibration isolation to have a comfortable ride to the vehicle occupant. This requires the mount to be soft.
2015-01-14
Technical Paper
2015-26-0130
Pradeep Kumar Singh
Gear noise and vibration in automobile transmissions is a phenomenon of great concern. Noise generated at the gearbox, due to gear meshing, also known as gear whine, gets transferred from the engine cabin to the passenger cabin via various transfer paths and is perceived as air borne noise to the passengers in the vehicle. This noise due to its tonal nature can be very uncomfortable to the passengers. Optimizing micro-geometry of a gear pair can help in improving the stress distribution on tooth flank and reducing the sound level of the tonal noise generated during the running of the gearbox when that gear pair is engaged. This technical paper contains the study of variation in noise level in passenger cabin and contact on tooth flank with change in micro-geometry parameters (involute slope and lead slope) of a particular gear pair. Further scope of study has been discussed at the end of the paper.
2015-01-14
Technical Paper
2015-26-0122
Herman Van der Auweraer, Karl Janssens, Fabio Bianciardi, Filip Deblauwe, Kumaraswamy Shivashankaraiah
Certification of vehicle noise emissions for passenger vehicles, motorcycles and light trucks is achieved by measuring external sound levels according to procedures defined by international standards such as ISO362. The current procedure based on a pass-by test during wide-open throttle acceleration is believed to be far from actual urban traffic conditions. Hence a new standard pass-by noise certification is the new ISO 362:2007 is being evaluated for implementation that puts testing departments through their paces with requirements for additional testing under multiple ‘real world’ conditions. The new ISO standard, together with the fact that most governments are imposing lower noise emission levels, makes that most of the current models don’t meet the new levels which will be imposed in the future. Therefore automotive manufacturers are looking for new tools which are giving them a better insight in the Pass-by Noise contributors.
2015-01-14
Technical Paper
2015-26-0124
Vilas Deoolkar
Pass – by testing is increasingly done In-door in a hemi-anechoic environment. Advantages of this method are high repeatability and independence of weather conditions. Often rooms smaller than the standardized size will provide accurate results. Product optimisation work often requires information about the noise contribution from the different vehicle noise sources. In this presentation different room sizes are discussed and an accurate time - based contribution analysis method is explained and documented with results from a practical example. Time domain has a number of advantages. The calculations are simple and hence the data are available for processing in other domains. It is possible to directly listen to the individual component contributions when working on exterior brand sound.
2015-01-14
Technical Paper
2015-26-0123
Yogesh Surkutwar, Mahesh Anand Patwardhan, Nagesh Voderahobli Karanth, Atul Gaikwad
Use of Combined CAE and Experimental Testing Approach for Engine Noise Reduction Y. V. Surkutwar, A. A. Gaikwad, M.A. Patwardhan, N.V. Karanth, ARAI Pune Abstract The work presented in this paper deals with the use of combined CAE and experimental testing approach for reducing engine noise. The paper describes a systematic approach for giving solutions to structure borne engine noise related problems. Noise Source Identification (NSI) was carried out on diesel engine to identify noise radiating sources, ranking of noise sources was carried out and contribution of individual engine component in radiated Sound Level (SWL) was computed. Detailed Finite Element model of Engine assembly was developed and model was correlated in terms of natural frequencies and transfer functions by performing modal testing. Correlated FE model was used for predicting surface vibration velocities under various engine speeds and loading conditions in frequency domain.
2015-01-14
Technical Paper
2015-26-0134
Jayant Sinha, Ajit Kharade, Shrihari Matsagar
An interior sound quality is one of the major performance attribute, as consumer envisage this as class and luxury of the vehicle. With increasing demand of quietness inside the cabin, car manufactures started focusing on noise refinement and source separation. This demand enforces hydraulic power steering pump to reduce noise like Moan and Whine, especially in silent gasoline engine. To meet these requirements, extensive testing and in-depth analysis of noise data is performed. Structured process is established to isolate noises and feasible solutions are provided considering following analysis. a) Overall airborne noise measurement at driver ear level (DEL) inside the cabin using vehicle interior microphone. b) Airborne and Pressure pulsation test by sweeping pump speed and pressure at test bench. c) Waterfall analysis of pump at hemi anechoic chamber for order tracking and noise determination.
2015-01-14
Technical Paper
2015-26-0135
Kalpesh Mistry, Steve Fisher, Nitin Badhe
Vehicle level Acoustic sound pack sensitivity and Test correlation by utilising Statistical Energy Analysis (SEA) technique for Premium SUV Kalpesh A. Mistry, Atul D. Pol, Ajay Virmalwar Tata Technologies Ltd., Pune, India Steve Fisher Jaguar Land Rover Ltd., Gaydon, UK SAE SIAT at India,2015 Abstract Due to increased awareness by customer perceived sound characteristics, advance simulation technique emerged in NVH domain for mid-high frequency like BEM, Hybrid and Statistical Energy Analysis (SEA). Structure-borne noise simulation primarily relies on the finite element (FE) technique and due to wide knowledge base, it is in position to get correlated results and prediction. One of the most widely and accepted practice is SEA to assess and optimize Acoustic sound pack for Air Borne Noise (ABN) in the range of 400 Hz to 10,000 Hz typically for Powertrain and Tyre Patch Noise Reduction. As Prof.
2015-01-14
Technical Paper
2015-26-0141
Ravishastri Gadasu, Anshul Khatri, Aashish Parmar
With increase in product diversity in passenger car market, the need for NVH comfort has gained very strong foothold in every segment. This needs in depth analysis for limiting the noise at part level. Radiator Fan Module is one of such part which contributes to Cabin comfort in major way. In this paper, author is focusing on designing of RFM in order to have low noise. Primary objective of RFM is to meet Heat rejection requirement with optimized air flow. Radiator Fan is primarily responsible for meeting air flow requirement within specified noise limit. For flow inducing components like Radiator Fan, there is always a trade-off between the functional requirement and the noise from various sources (Electrical / Mechanical / Flow). Design of Fan blades and Motor Support ribs in RFM is critical to improve Flow noise, i.e. Air cutting noise.
2015-01-14
Technical Paper
2015-26-0139
Pradeep Kumar Singh
Noise generated in the driveline is mainly transferred inside the passenger cabin through air (air borne noise) and through the vehicle body structure, engine mounts, cables etc. Source of the noise generation in the vehicle is mainly through the engine fluctuation (engine combustion excitations). Any change in the engine characteristics results in the change in passenger cabin noise. Also, influence of the vehicle body structure due to change in material properties also affects the NVH performance. This technical paper explains the effect of change in engine characteristics as well as change in the transfer path due to design change on the NVH performance of the gear box and subsequently the NVH performance of vehicle.
2015-01-14
Journal Article
2015-26-0131
Abhishek Verma, M. L. Munjal
In this work, the noise attenuation characteristics of a three-chamber U-bend hybrid muffler have been investigated. Acoustic performance is quantified by the Transmission Loss (TL) parameter. One-dimensional transfer matrix based muffler program (TMMP) and three-dimensional finite element method (FEM) have been used for the prediction of the TL of the muffler. Presence of perforated baffles in geometry necessitates use of the Integrated Transfer Matrix (ITM) approach for the one-dimensional analysis because the sound fields in the elements would be coupled with each other, and for the 3D FEM analysis LMS Virtual Lab software has been used. The mean flow distribution in each of these configurations has been evaluated by means of a lumped flow resistance network. The resulting values of the grazing flow and bias flow have been used in the expressions for acoustic impedance of the perforates.
2015-01-14
Journal Article
2015-26-0136
Deepak Mahajan, Arnab Sandilya, Lokesh Khandelwal, Sameer Srivastava
Automotive floor carpet serves the purpose of insulating air borne noises like road/tire noise, transmission noise and fuel pump noise etc. Most commonly used automotive floor carpet structure is - Molded sound barrier (PE or vinyl etc) decoupled from floor pan with an absorber such as felt. With increasing customer expectations and fuel efficiency requirements, the NVH requirements are increasing as well. The only possible way of increasing acoustic performance (Specifically Sound Transmission Loss, STL) in the mentioned carpet structure is to increase the Barrier material. This solution, however, comes at a great weight penalty. Theoretically, increasing the number of decoupled barriers layers greatly enhances the STL performance of an acoustic packaging for same weight. However, practically this solution presents problems like- ineffectiveness at lower frequencies, sudden dip in performance at modal frequencies.
2015-01-14
Technical Paper
2015-26-0140
Milind Ambardekar, Adatiya Yogesh, Sudhakara Naidu
A Power-train Mounting System [PTMS] of a passenger car or a Truck provides isolation and damping against excitations from engine and driveline to the vehicle-body to assure low levels of tactile vibrations and structure-borne noise for the passengers. In a competitive market where faster product development is expected, design sign-off for is needed much before Final Design Judgment of the vehicle. This Paper discusses robustness needed in the Design Validation Plan [DVP] of PTMS to capture Voice of Customer against a typical case like idle-shake of a high powered Truck [Fig. 1]. Production variations of Truck vibrations were measured and then analyzed through an Ishikawa diagram. Noise Factors, Error Status and Control factors of the Truck under study were indentified. Modal Alignment of PTMS was studied by an in-house developed multi-body dynamics tool.
2015-01-14
Technical Paper
2015-26-0234
Ramesh Pathuri, Yuvraj Patil, Prasanna Vyankatesh Nagarhalli
During early phases of vehicle program, evaluation of Air Conditioning (AC) system for its performance (time to comfort) and power consumption has become vital and hence simulation tools have gained tremendous importance. A 1D simulation model can be introduced early in the design process to evaluate several AC system configurations and parametric studies at different test conditions and which results in reduced experimental work. This paper presents a method for AC cool down simulation of passenger car with multi air zone cabin model in KULI. This approach allows the prediction of zone wise (head, body and foot) temperature and humidity distribution in the cabin for parameter studies for transient analysis. The same cabin model can deal with multiple inlets into the cabin, solar radiation, and recirculation for pre-defined cabin types.
2015-01-14
Technical Paper
2015-26-0129
Kapil Gupta, Vikram MR, Eugenio Manta
ABSTRACT A turbocharger unit mainly consists of a centrifugal compressor and a turbine coupled together by a solid shaft. This is employed to boost the charge air pressure of engine. Turbocharging in modern diesel and gasoline engines have become a common and essential operation to result higher power outputs, lower emissions, improved efficiency and refinements from a similar capacity of naturally aspirated engine. The automotive turbocharger system is a source of synchronous and asynchronous noises which are particularly very disturbing for the passengers. This need to be eliminated or reduced for passenger comfort. Subjectively, a high whistle noise was audible at passenger cabin during in mid-rpm range drive in all gears in a 4 cylinder diesel vehicle. Objective noise and vibration data confirm the issue as unbalance whistle.
2014-11-23
WIP Standard
AS8040C
This SAE Aerospace Standard (AS) covers combustion heaters used in the following applications: a. Cabin heating (all occupied regions and windshield heating) b. Wing and empennage anti-icing c. Engine and accessory heating (when heater is installed as part of the aircraft) d. Aircraft de-icing
2014-10-28
Standard
J384_201410
This SAE Recommended Practice specifies performance requirements and test procedures for the strength and location of seat belt assembly anchorages. It applies to seat belt anchorages attached to vehicle body structure or to seat assemblies in the vehicle. Design Considerations are specified in SAE J383.
2014-07-10
Magazine
Off-highway engines advance beyond Tier 4 With Tier 4 Final/Stage IV needs met, engine OEMs direct their focus and competitive energies toward optimizing competitive solutions. At the same time, they need to keep a weather eye out for future regulations, which many expect. Autonomous vehicle challenges span many fields Many of the challenges faced by military and commercial design teams are similar. Racket busters With a quiet cab at the top of many tractor buyers' wish lists, agricultural equipment manufacturers are pursuing every opportunity possible to shed decibels.
2014-07-01
Standard
AIR4362A
This SAE Aerospace Information Report (AIR) provides Nuclear, Biological and Chemical (NBC) protection considerations for environmental control system (ECS) design. It is intended to familiarize the ECS designer with the subject in order to know what information will be required to do an ECS design where NBC protection is a requirement. This is not intended to be a thorough discussion of NBC protection. Such a document would be large and would be classified. Topics of NBC protection that are more pertinent to the ECS designer are discussed in more detail. Those of peripheral interest, but of which the ECS designer should be aware are briefly discussed. Only radiological aspects of nuclear blast are discussed. The term CBR (Chemical, Biological, and Radiological) has been used to contrast with NBC to indicate that only the radiological aspects of a nuclear blast are being discussed.
2014-04-01
Technical Paper
2014-01-0890
Shuming Chen, Dengzhi Peng, Dengfeng Wang
Abstract Automobile cabin acoustical comfort is one of the main features that may attract customers to purchase a new car. The acoustic cavity mode of the car has an effect on the acoustical comfort. To identify the factors affecting computing accuracy of the acoustic mode, three different element type and six different element size acoustic finite element models of an automobile passenger compartment are developed and experimentally assessed. The three different element type models are meshed in three different ways, tetrahedral elements, hexahedral elements and node coupling tetrahedral and hexahedral elements (tetra-hexahedral elements). The six different element size models are meshed with hexahedral element varies from 50mm to 75mm. Modal analysis test of the passenger car is conducted using loudspeaker excitation to identify the compartment cavity modes.
2014-04-01
Technical Paper
2014-01-0881
Mitsuru Enomoto, Michiko Kakinuma, Nobuhito Kato, Haruo Ishikawa, Yuichiro Hirose
Abstract Design work for truck suspension systems requires multi-objective optimization using a large number of parameters that cannot be solved in a simple way. This paper proposes a process-based systematization concept for ride comfort design using a set-based design method. A truck was modeled with a minimum of 13 degrees of freedom, and suspension performance under various vehicle speeds, road surface conditions, and load amounts was calculated. The range of design parameters for the suspension, the range of performance requirements, and the optimal values within these ranges were defined based on the knowledge and know-how of experienced design engineers. The final design of the suspension was installed in a prototype truck and evaluated. The performance of the truck satisfied all the objectives and the effectiveness of the set-based design approach was confirmed.
2014-04-01
Technical Paper
2014-01-0426
Jeff D. Colwell
Abstract Results from a full-scale vehicle burn test involving a 1998 compact passenger car were used to evaluate vehicle fire dynamics and how burn patterns produced during the fire correlated with important characteristics of the fire, such as the area of origin. After the fire was initiated at the air filter in the engine compartment, the fire spread locally and, once the temperature near the origin reached about 750°C, the temperature at all but one location within the engine compartment began to increase. These temperatures continued to increase for the next 6 minutes and then a temperature gradient began to develop in the passenger compartment between the ceiling and the floor. About 5 minutes after the engine compartment became fully involved, the ceiling temperature reached about 590°C and flame spread within the passenger compartment increased. Over the next 4 minutes, the passenger compartment also became fully involved.
2014-04-01
Journal Article
2014-01-0348
Rajiv Mehta, Mark Hadley
With the ever increasing pressure to improve the fuel economy of vehicles, there has been a corresponding interest in reducing the mass and size of vehicles. While mass is easily quantifiable, vehicle size, particularly the notion of “interior space” as perceived by the customer, is not. This paper explores different ways in which vehicle spaciousness can be quantified and explores new metrics based on customer verbatims. A novel ‘spaciousness calculator’ combines individual metrics to provide a singular holistic rating for spaciousness, useful during vehicle development. Beyond spaciousness, the paper discusses techniques to quantify the ‘packaging efficiency’ of a vehicle; this allows engineers to maximize the interior space for a given exterior size.
2014-04-01
Journal Article
2014-01-0687
Rupesh Sonu Kakade
We propose a composite thermal model of the vehicle passenger compartment that can be used to predict and analyze thermal comfort of the occupants of a vehicle. Physical model is developed using heat flow in and out of the passenger compartment space, comprised of glasses, roof, seats, dashboard, etc. Use of a model under a wide variety of test conditions have shown high sensitivity of compartment air temperature to changes in the outside air temperature, solar heat load, temperature and mass flow of duct outlet air from the climate control system of a vehicle. Use of this model has subsequently reduced empiricism and extensive experimental tests for design and tuning of the automatic climate control system. Simulation of the model allowed several changes to the designs well before the prototype hardware is available.
2014-04-01
Technical Paper
2014-01-0702
Kamalesh Bhambare, Junya Fukuyama, Jaehoon Han, Kosuke Masuzawa, Akihiro Iwanaga, Steven Patterson
Abstract The climate inside a vehicle cabin is affected by the performance of the vehicle HVAC system, the thermal characteristics of the vehicle structure and the components, as well as the external environmental conditions. Due to the complex interactions among these various factors, the flow field and the temperature distribution can be very complicated. The need for a fully three-dimensional transient analysis is increasing in order to provide sufficiently detailed information that can be used to improve the vehicle design. In this study, a numerical simulation methodology to predict the local climate conditions in a passenger vehicle cabin is presented. The convective heat transfer from both the exterior and the interior of the cabin were calculated by three dimensional CFD simulations using a Lattice-Boltzmann method based flow solver.
2014-03-25
WIP Standard
J1477
This SAE Recommended Practice establishes the test procedure, environment, instrumentation, and data analyses for comparing interior sound level of passenger cars, multipurpose vehicles, and light trucks having gross vehicle weight rating (GVWR) of 4540 kg (10 000 lb) or less. The test procedure is characterized by having fixed initial conditions (specified initial vehicle speed and gear selection at the starting point on the test site) to obtain vehicle interior sound measurement during road load operation over various road surfaces at specified constant speeds. The measurement data so derived is useful for vehicle engineering development and analysis.
2014-03-04
Magazine
Touch-less control coming to cars Use of proximity and gesture-recognition systems in auto cockpits could rise fifty-fold within a decade. Forming a strong bond Multi-material vehicles are becoming more prevalent as automakers attempt to reduce vehicle weight and boost fuel efficiency. Selecting the proper adhesive is critical when bonding dissimilar materials. SAE 2014 World Congress preview special section: 'Creating New Possibilities' Host company Hyundai and Tier 1 Strategic Partner, Delphi, established "Creating New Possibilities" as the theme for this year's premier engineering event taking place April 8-10 in Detroit's Cobo Center. This special Congress preview section uncovers some of those possibilities, featuring insights from the event's executive leadership; details of a Delphi/Hyundai advanced engine program; highlights from the technical program in the areas of powertrain, materials, testing and simulation, electronics, interiors, and body/chassis; and more.
2013-09-03
Magazine
Honda flexes new powertrain muscle Honda R&D's top engineer outlines his company's Earth Dreams powertrain assault that includes more efficient, robust, and refined ICEs; new hybrid drive systems; and further developments in FCEVs, HCCI, plasma ignitions, and Rankine-cycle engine types. Setting Hyundai's fuel cell strategy Hyundai is one of two major OEMs that are still going it alone in developing FCEV technology, rather than collaborating with competitors. The company's head of fuel cell R&D explains the path toward 2015 series production. Volvo Trucks makes a case for DME The truck maker is working with Oberon Fuels and others to bring dimethyl ether-what company execs say is one of the most promising sustainable alternative fuels-to North America in 2015. Sensing a need for creature comforts Automakers and suppliers are turning to new sensors to help make cabins more comfortable and safer while automating some tasks.
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