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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
2015-26-0196
Soujanya C, V Sundaram, Sathish Kumar S
Cooling system is one of the important systems of an Engine to maintain the optimum temperatures across engine and its components. Analysis of cooling system at initial phase of product development will help in optimum design of the system. Simulation plays a vital role in optimum design. In the System level simulation it is important to accurately model and discretize the components in the system in order to achieve optimum system level flow balancing and flow prediction. As engine coolant jacket is the major contributor of pressure drop in cooling system, its modelling strategy will have high influence on results predictions across the system. Simulation of engine cooling system with Split engine coolant water jacket is challenging. It is difficult to achieve the simulation results close to bench test due to complexity of the system.
2015-01-14
Technical Paper
2015-26-0129
Kapil Gupta, MR Vikram, 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.
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
2015-26-0210
Nilesh Daithankar, Kishor D Udawant, Nagesh Voderahobli Karanth
This paper presents a methodology for predicting thermal comfort inside midibus cabin with an objective to modify the HVAC duct design and parametric optimization in order to have improved thermal comfort of occupant. For this purpose the bus cavity is extracted from baseline CAD model including fully seated manikins with various seating positions. Solar Load has been considered in the computational model and passenger heat load is considered as per BSR/ASHRAE 55-1992R standard. CFD simulation predicted the air temperature and velocity distribution inside passenger cabin of the baseline model. The experimental measurements have been carried out as per the guidelines set in APTA-BT-RP-003-07 standard. The results obtained from CFD and Experimental test were analysed as per EVS EN ISO7730 standard and calculated occupant comfort in terms of thermal comfort parameters like Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD).
2015-01-14
Technical Paper
2015-26-0235
Raju P Soudatti, Ragunathan Amarnath, Ramesh Harish
This paper deals the verification & Validation of passenger seat of buses for life cycle requirement. Through various methodologies adopted from Data collection, CAE verification and physical validation to verify the seat in virtual environment. Generally it is observed that in City Buses most of the time Passenger seat leg mounting area failures occurs in buses used for typically more than 3years. This fatigue failure doesn't get captured in either Anchorage test or limited vibration test. Passenger seats durability should be equal to vehicle life which is 10L or 12 Years of life span. Testing on Physical vibration (Rig) machine is time consuming and costly most of the time Machine availability for testing will be an issue to validate alternate seat proposals. There is need to establish a correlation between Physical testing and CAE simulation so that alternate proposals can be easily and quickly verified using CAE alone.
2015-01-14
Technical Paper
2015-26-0043
Rajesh Kashyap, Vamsidhar Sunkari, Prakash Verma
Regular service of the vehicle is to be done to ensure the factory performance of the vehicle over the entire life of product usage. However, complex nature of the physical processes involved in the service of the vehicle subsystems makes it costly for optimizing the service equipment performance for entire range of operation. Air-conditioning service (ACS) equipment is one such product in the diagnostics domain which deals with compressible, transient and two phase flow in open loop systems. Development of design controls for the service equipment to perform optimally over the entire operational range requires accurate mathematical model of the system under study. Application of mathematical model based approach requires calculation of geometrical details, environment information and fluid properties during the process for estimating the process behavior.
2015-01-14
Technical Paper
2015-26-0026
Suresh Kumar Gurusamy, R Sateesh Kumar, Janga Sridhar Reddy, P Chitnis
Abstract Nowadays, on average, two third of the fuel energy consumed by an engine is wasted through the exhaust gases and the coolant. Since most of the energy consumed by an internal combustion engine is wasted, recovering much of that wasted energy can provide a significant increase in energy efficiency. A turbo-generator system is designed and developed for recovering a 3 percent of exhaust heat in the form of electricity. A theoretical model of the system is developed and the amount of energy that can be recovered using the system is estimated. The theoretical model is verified by testing a turbocharger in series with the existing turbocharger. A full scale prototype of the turbo-generator is developed based on the theoretical model and experimental results. A bypass system with throttle is developed to reduce the backpressure created by the turbogenerator. The model is tested on an engine test bench at full load and part load conditions.
2015-01-14
Technical Paper
2015-26-0045
Rico Baumgart, Joerg Aurich, Jan Ackermann, Christoph Danzer
Abstract The development of energy efficient air conditioning systems for electric vehicles is an ever increasing challenge, because the cooling as well as the heating of the passenger compartment reduces the cruising range dramatically. Electric cars are usually equipped with a scroll compressor and a separate electric motor with appropriate power electronics. However, this solution is critical in terms of the installation space, the weight and also the costs. Therefore, an innovative and energy efficient drivetrain structure for electric vehicles was developed, which integrates the motor of the A/C-compressor directly into the drivetrain. Thus it is possible to switch off the compressor motor and to use the main motor for the drive of the compressor at certain driving situations. As a result, the operating point of the main motor can be shifted to a better efficiency.
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
2015-26-0139
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
Technical Paper
2015-26-0157
Kedar Madhukar Hendre, Yogesh Purohit
Curtain airbag design offers protection in side crash and it plays a critical role in safety of the vehicle. Curtain airbag provides protection to the occupant in many impact events like frontal offset, side barrier, side pole and rollover condition. For a vehicle to be safe for any side impact condition, the curtain airbag should deploy and take its final shape before any injury happens to the occupant. During deployment, it is important that the airbag chooses a path of minimum resistance and does not get entangled in interior trims. In reality, the trims always do obstruct the path of airbag deployment in some way. Hence, special care has to be taken care for designing areas surrounding curtain like providing hinges, deflector components etc. to avoid being caught. There are about ten different factors on this deployment is dependent upon. This paper discusses these factors and the effect of the factors on the trims and airbag development.
2015-01-14
Technical Paper
2015-26-0140
Milind Ambardekar, Adatiya Yogesh, Sudhakara Naidu
Abstract Production variations of a heavy duty truck for its vibrations were measured and then analyzed through an Ishikawa diagram. Noise and Control factors of the truck idle shake were indentified. The major cause was found to be piece to piece variations of its power-train (PT) rubber mounts. To overcome the same, a new nominal level of the mount stiffness was sought based on minimization of a cost function related to vibration transmissibility and fatigue damage of the mounts under dynamic loadings. Physical prototypes of such mounts were proved to minimize the variations of the driver's seat shake at idling among various trucks of the same design. These learning's are useful for design of various subsystems or components to refine the full vehicle-Noise Vibration Harshness (NVH) at the robust design level.
2015-01-14
Technical Paper
2015-26-0044
Sambhaji Keshaw Jaybhay, Prasanna Nagarhalli, Suresh Tadigadapa, Sangeet Hari Kapoor
Context- In order to enhance fuel efficiency in buses an energy efficient air conditioning system should be deployed. This will lead to reduced parasitic load on the engine and translate into direct fuel saving. Fuel prices are increasing day by day; along with rapid depletion of fuel sources. Alternate fuels like CNG need investments in infrastructure, which is not available easily everywhere. Therefore fuel saving is vital. In case of air conditioned vehicles, the parasitic load mainly consists of power consumed by air conditioning compressor to pump the refrigerant and by blower motors and condenser fans for movement of conditioned air and heat removal respectively. Furthermore roof mounted bus air conditioning systems weigh in the range of 150-220kg (approx.) adding to the payload Necessity- Now days, most mid-size air conditioned buses are equipped with aftermarket solutions.
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
2015-26-0127
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
2015-26-0125
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
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
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
2015-26-0156
Anil Kumar Jaswal, MV Rajasekhar, J Perumal, Samir Rawte
Vehicle Safety is always been in prime focus for development engineers while introducing newer products in markets for the customers. It is now common to see vehicles catching fire on roads and in parking places leading to destruction of the surroundings as well as hazard to the passengers. Thermal events can take place due to the heat dissipated by the heat emitters such as Engine, Turbo, Alternator, Exhaust System etc. The most critical area where Thermal events can usually take place are under hoods which includes the complete engine compartment and under body area. The extent of fire depends on the fire source, characteristics of the materials used in constructing and furnishing the vehicle. The Performance and life of Electronic parts and parts made of polymeric materials such as rubbers and plastics are also greatly influenced by the temperatures of their surroundings.
2015-01-14
Technical Paper
2015-26-0158
Vijesh Chinnadurai, Hima Kiran Vithal Venna, Vinod Banthia
Abstract Expanding and improving road network in India has been a catalyst for increased use of road transport in both passenger and goods sector. With improved road quality, bigger commercials vehicles have entered the market. These provide a larger cabin area and better amenities in the truck driver cabin. One of the most welcome features is berths for lying down and sleeping. In most designs though, only the functionality of the berth has been taken into consideration. Safety of the occupants of the berths in the event of panic braking or collision of the vehicle, has not been given adequate consideration. In this work, design of such berths from occupant safety point of view has been assessed. Kinematics of occupants, sleeping in different typical postures, during frontal impact, has been simulated and resulting critical injury levels have been estimated. Based on this information, different arrangements of belts in “screen” type configuration were developed.
2015-01-14
Technical Paper
2015-26-0151
Ganesh Dharmar, Hareesh Krishnan, Riyaz Mohammed, Ravichandrika Bhamidipati
Abstract Recent trends in vehicle occupant protection have led to renewed interest in the perception of Roominess such as headroom, shoulder room and foot room etc. Occupants head room in vehicles is currently measured using tools, procedures and definitions described in SAE J1052 and J1100. “Head Position Contours” defined in SAE J1052 are useful in establishing accommodation requirements for head space [1]. With respect to the Indian Anthropometry database, the head position contour as per SAE J1052 will not be appropriate with Indian population. With this objective in mind a head movement envelope is generated using the software - RAMSIS Digital manikin. RAMSIS is widely used by Automobile Manufacturers for Digital Human Modeling. The head movement envelope is a collation of different movements of head during driving condition.
2014-12-16
Article
Ford recently unveiled its Sync 3 in-car infotainment system that will launch in select vehicles next year. In this episode of SAE Eye on Engineering, Senior Editor Lindsay Brooke looks at Ford's new system and its improvements over the previous version. 
2014-12-15
Article
Thermo Pro 90 and Thermo Pro 50 engine-off coolant heating systems from Webasto are designed for use in specialty commercial vehicles and off-highway equipment.
2014-12-11
Standard
J2912_201412
This SAE Standard applies to refrigerant identification equipment to be used for identifying refrigerant HFC-134a (R-134a) and HFO-1234yf (R-1234yf) refrigerant when servicing a mobile A/C system or for identifying refrigerant in a container to be used to charge a mobile A/C system. Identification of other refrigerants is the option of the equipment manufacturer, although it shall not misidentify refrigerants, per 3.2.
2014-12-03
Standard
J1948_201412
This SAE Recommended Practice provides a standardized test procedure for heavy-duty truck sleeper berth restraints to determine whether they meet the FMCSR 393.76(h) requirements.
2014-12-03
Standard
J1522_201412
This SAE Recommended Practice describes two-dimensional 95th percentile truck driver side view, seated stomach contours for horizontally adjustable seats (see Figure 1). There is one contour and three locating lines to accommodate male-to-female ratios of 50:50, 75:25, and 90:10 to 95:5.
2014-12-03
Standard
J1521_201412
This SAE Recommended Practice describes two-dimensional, 95th percentile truck driver, side view, seated shin-knee contours for both the accelerator operating leg and the clutch operating leg for horizontally adjustable seats (see Figure 1). There is one contour for the clutch shin-knee and one contour for the accelerator shin-knee. There are three locating equations for each curve to accommodate male-to-female ratios of 50:50, 75:25, and 90:10 to 95:5.
2014-12-02
Article
Toyota today called for a coordinated industry-wide joint initiative to independently test Takata airbag inflators that have been the subject of recent recalls by several automakers. "By combining our collective efforts behind a coordinated, comprehensive testing program, we believe we can achieve greater results.
2014-12-01
Standard
AS5452B
This SAE Aerospace Standard (AS) will specify what type night vision goggles are required, minimum requirements for compatible crew station lighting, aircraft exterior lighting such as anticollision lights and position/navigation lights that are "NVG compatible." Also, this document is intended to set standards for NVG utilization for aircraft so that special use aircraft such as the Coast Guard, Border Patrol, Air Rescue, Police Department, Medivacs, etc., will be better equipped to chase drug smugglers and catch illegal immigrants, rescue people in distress, reduce high-speed chases through city streets by police, etc. Test programs and pilot operator programs are required. For those people designing or modifying civil aircraft to be NVG compatible, the documents listed in 2.1.3 are essential.
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