Abstract One method to lower noise in a cabin is to position damping layers on vibrating panels, thereby reducing their radiated power. To assess the damping effect, criteria like the ERP (equivalent radiated power) are widely employed, which estimate the radiated sound power of a panel without taking into account the actual complex system. Advantageously only a part of the structure has to be modeled, but the optimal solution found on the simplified model then often fails for the complete, coupled system, especially if several variants of a cabin have to be considered. Hence, it is proposed to use the structure-only optimization for identification of a set of candidate solutions for optimal positioning of damping layers. These candidate solutions used as initial designs for the coupled investigations should be well distributed in the design space to avoid being wrongly stuck in an optimum with inferior coupled performance.
Experimental Method for Transposition of Dynamic Forces Generated by an Active Component from a Test Bench to a Vehicle: a New Standard
Abstract The control of sound fields radiated by vibrating structures in a passenger compartment, (especially structures connected to different organs like the engine powertrain, the fan motor unit, seats, the steering column, electrical motors more and more, etc.) is among the functions of the automotive manufacturers. The absence of physical prototypes in the development phase systems led OEMs1 to use tests results obtained on benches following technical specifications from manufacturers. The transition "bench to vehicle" for vibro- acoustic behaviour sets many challenges that this standard intends to clear up. This standard specifies the experimental method to transpose the dynamic forces generated by the global movements of an active component between the vehicle and a test bench. The efforts are first measured on test benches and then transposed from test bench towards the vehicle. The standard is now a French standard (XP R 19-701) and is submitted to ISO process .
Base-engine value engineering for higher fuel efficiency and enhanced performance Continuous improvement in existing engines can be efficiently achieved with a value engineering approach. The integration of product development with value engineering ensures the achievement of specified targets in a systematic manner and within a defined timeframe. Integrated system engineering for valvetrain design and development of a high-speed diesel engine The lead time for engine development has reduced significantly with the advent of advanced simulation techniques. Cars poised to become 'a thing' Making automobiles part of the Internet of Things brings both risks and rewards. Agility training for cars Chassis component suppliers refine vehicle dynamics at the high end and entry level with four-wheel steering and adaptive damping.
New dawn at Honda R&D President Yoshiyuki Matsumoto aims to invigorate Honda's technology and product-development organization with 'full soul.' Automated driving meets regulation: NHTSA and the next 50 years The challenges and opportunities on the road to 'zero deaths' demand a new level of federal automotive safety technical standards, and a new safety-defect reporting and recall system. NHTSA and the U.S. Congress must act boldly and quickly to make it happen. Autonomous driving meets regulation: Hands off, eyes off, brain off Euro NCAP'S president warns that without coherent policies, the growing availability of automated technologies may result in piecemeal technology development-and unintentional consequences. Designer yin meets engineer yang Efficient and effective vehicle development means even closer collaboration between the two former sparring partners.
Abstract The adoption of a low-GWP refrigerant gas in MAC systems is mandatory from January 1st, 2017 according to the European Directive 2006/40/EC requirements for all new passenger cars, in order to gain their registration in the EU28 market. Following the work carried out in 2008 to support the FCA choice for the new types development, a further step was accomplished to evaluate the risk involved by the adoption of the low-GWP refrigerant gas R-1234yf in the MAC systems. This paper is focused on the activities held to enhance the 3D CFD method and its validation. In certain concentrations, R-1234yf could present a safety hazard to the vehicle occupants and, according to the ISO Standard Risk Scenario evaluation, 3D CFD tools are adopted to evaluate the ignition event associated with small or large leak in the passenger compartment. The method validation has been supported by both a simplified control volume “dummy cabin compartment” and an actual FCA vehicle.
Abstract The main function of an air conditioning system in a vehicle is to provide the thermal comfort to the occupant at minimum possible energy consumption in all environmental conditions. To ensure the best possible thermal comfort, air conditioning system is optimized on various parameters like heat load, air flow distribution, glass area, trim quality, insulations and cabin leak rate. A minimum cabin leakage is regulatory requirements to ensure the air quality of cabin. Anything above the minimum cabin leak rate ultimately turn into reduced thermal comfort and additional energy consumption. The additional energy consumption to maintain the required thermal comfort in the cabin due to cabin leakage affects the fuel efficiency severely. In the present study, the effect of cabin leakage on fuel efficiency and thermal comfort is studied in details by varying the cabin leakage through mechanical means.
Abstract North American customer perception of Quality has changed over time and has shifted from Quality, Dependability, and Reliability (QDR) to Interior Sensory Quality (ISQ). ISQ is defined as the harmony of characteristics that combine to make an emotional connection to the vehicles’ interior. Vehicles need to correctly appeal to customers emotional side through providing class-leading ISQ. Hypotheses for specific interior areas were developed in order to identify key ISQ strengths, weaknesses, and preferences. These hypotheses were then tested at customer clinics held across the country. The key goals were to understand customer judgment of ISQ execution, understand customer ISQ priority, and understand customer preference of detailed component areas.
A New Method of Characterizing Wind Noise Sources and Body Response for a Detailed Analysis of the Noise Transmission Mechanism
Abstract Interior noise caused by exterior air flow, or wind noise, is one of the noise-and-vibration phenomena for which a systematic simulation method has been desired for enabling their prediction. One of the main difficulties in simulating wind noise is that, unlike most other noises from the engine or road input, wind noise has not one but two different types of sources, namely, convective and acoustic ones. Therefore, in order to synthesize the interior sound pressure level (SPL), the body sensitivities (interior SPL/outer source level) for both types of sources have to be considered. In particular, sensitivity to the convective input has not been well understood, and hence it has not been determined. Moreover, the high-frequency nature of wind noise (e.g., the main energy range extends up to 4000 Hz) has limited the effective application of CAE for determining body sensitivities, for example, from the side window glass to the occupants’ ears.
This report provides data and general analysis methods for calculation of internal and external, pressurized and unpressurized airplane compartment pressures during rapid discharge of cabin pressure. References to the applicable current FAA and EASA rules and advisory material are provided. While rules and interpretations can be expected to evolve, numerous airplanes have been approved under current and past rules that will have a continuing need for analysis of production and field modifications, alterations and repairs. The data and basic principles provided by this report are adaptable to any compartment decompression analysis requirement.
Accelerated Exposure of Automotive Interior Trim Material Using Outdoor Under-Glass Controlled Sun-Tracking Temperature and Humidity Apparatus
This SAE Standard specifies operating procedure for the exposure of automotive interior trim materials in an outdoor behind-glass apparatus in which the temperature is controlled in a 24 h cycle. The humidity is controlled during the dark (night) portion of the cycle. Specimen preparation, test durations, and performance evaluation procedures are covered in material specifications of the different automotive manufacturers.
Multi-material structures move mpg upward The quest to improve fuel economy is not waning, nor is the desire to achieve higher mpg through the use of just the right lightweight material for the right vehicle application. Cars poised to become 'a thing' Making automobiles part of the Internet of Things brings both risks and rewards. Agility training for cars Chassis component suppliers refine vehicle dynamics at the high end and entry level with four-wheel steering and adaptive damping. SAE 2016 World Congress Preview Technology trends and exhibitor products are highlighted in this special section, which features Toyota's plans for the show floor, tech sessions, and more.
Off-highway hybrids: Opportunities and challenges With oil prices declining and emissions regulations in North America 'stabilized,' is there a place for hybrid powertrains in this new world of cheap oil? Looking for a better image Display advances are helping to reduce operator fatigue. Charging up electrified powertrains Control technologies race forward while batteries improve and adopt standard sizes. Measuring and accounting for suspension TARDEC teamed with SEA Ltd. to develop a system to measure the suspension parameters, center of gravity, and moments of inertia of wheeled vehicles in the never ending quest to model and predict vehicle dynamic behavior. Looking at mobility in 2050 Cuneyt L. Oge begins his term as 2016 SAE International President with a vision about the future of auto- and aero-mobility.
Abstract Our team aims towards designing, validating and fabricating an electro-mechanical device that can dynamically control the inside temperature of the vehicle depending upon the outside temperature conditions. This device purely uses non-conventional source of energy and is economical to install and operate. Vehicle temperature modulator is designed keeping in mind the environment and weather conditions of South East Asian Nations and can be further modified according to the norms of any other country. This unit is capable of being employed in any segment vehicle present in India i.e. A1, A2, A3, A4, A5, A6, B1, B2 and SUV.
Abstract New generation automobiles are equipped with power windows which eases the passenger’s effort in moving the vehicle windows up and down. Many of them are stuffed with advanced features like automatic up/down option for ensuring functionality with a single press of the switch. Even though it adds comfort to driver & passenger, inadvertent use of power window can be fatal if a person’s body part gets trapped inside. An effective solution for this problem is anti-pinch mechanism, which releases the object safely just when it gets trapped. It detects the object trapped and immediately moves the window down so that trapped object will get released easily. The anti-pinch algorithm used in this project is based on the “Method of Monitoring Movable Element”, method monitor traveling distance of a power window pane. In order to achieve this different from conventional techniques we are using Ultrasonic sensor.
Abstract The cabin or cab is an enclosed space where the driver and co-driver are seated. Structural parameters such as modal and stiffness characteristics are of key importance for its durability study and driver’s comfort. The desired strength and stiffness value of the cabin have to be met at the development phase itself. In developing new cabin models numerical simulations are used for estimating vehicle performance to reduce the development cycle. But, the conventional method of modeling the cabin using 2-d elements and performing subsequent iteration steps to arrive at the desired stiffness and strength value will be cumbersome and time consuming. Thus, a methodology of FE modeling of the truck cabin using 1-D elements has been proposed in this paper which will reduce the analysis time of successive iterations. For this purpose an existing proven driver’s cabin is modeled using 1-D elements.
Abstract In recent years fuel consumption of passenger vehicles has received increasing attention by customers, the automotive industry, regulatory agencies and academia. However, some areas which affect the fuel consumption have received relatively small interest. One of these areas is the total energy used for vehicle interior climate which can have a large effect on real-world fuel consumption. Although there are several methods described in the literature for analyzing fuel consumption for parts of the climate control system, especially the Air-Condition (AC) system, the total fuel consumption including the vehicle interior climate has often been ignored, both in complete vehicle testing and simulation. The purpose of this research was to develop a model that predicts the total energy use for the vehicle interior climate.
Uncertainty quantification The technique is a must for next-generation simulation tools. Oil-pump sizing Researchers from Hinduja Tech investigate options for low friction and power consumption. The future of Indian commercial aviation The growth in traffic that airport modernization has supported has also made a significant contribution to the local and national economies, while the improved infrastructure has been positive for the perception of India in the global market. Driving EVs toward lower cost The race ison to reduce battery and electric-drive systems cost while improving efficiency. Powering on Rolls-Royce's Chief Engineer discusses new technologies that inspire current R&D design and evaluation work as part of its strategic roadmap for future big commercial programs. HMIs extend beyond the cab Telematic functions are being integrated into multi-function user interfaces.
The devices of this SAE Standard provide the means by which passenger compartment dimensions can be obtained using a deflected seat rather than a free seat contour as a reference for defining seating space. All definitions and dimensions used in conjunction with this document are described in SAE J1100. These devices are intended only to apply to the driver side or center occupant seating spaces and are not to be construed as instruments which measure or indicate occupant capabilities or comfort. This document covers only one H-point machine installed on a seat during each test. Certified H-point templates and machines can be purchased from: SAE International 400 Commonwealth Drive Warrendale, PA 15096-0001 Specific procedures are included in Appendix A for seat measurements in short- and long-coupled vehicles and in Appendix B for measurement of the driver seat cushion angle. Specifications and a calibration inspection procedure for the H-point machine are given in Appendix C.
Off-Road Self-Propelled Work Machines Operator Enclosure Environment Part 6: Determination of Effect of Solar Heating
SAE J3078/6 specifies a test method for simulating solar heating in the laboratory and measuring the radiant heat energy from a natural or simulated source. It is applicable to Off-Road Self-Propelled Work Machines as defined in SAE J1116 and Agricultural Tractors as defined in ANSI/ASAE S390.
Abstract This work aims the implementation of a system able to estimate the occupancy rate (number of occupants) inside motor vehicles. This system is based on a Wireless Sensors Network using the standard IEEE 802.15.4, connected to a computer. The estimation of occupancy rate inside the motor vehicle can provide better energy efficiency and therefore optimize fuel and battery consumption.
Abstract Nowadays CFD analysis including virtual manikins is vastly applied to evaluate thermal comfort inside different working environments, such as buildings cars and aircrafts. Inside aircraft cabins, added to the numerical challenges due to geometrical complexity, the available subjective responses used to judge occupant local thermal comfort are usually based on buildings and cars experiments . In the present paper however, it is applied an aircraft based subjective responses to evaluate thermal comfort which was specifically developed using regional jet mock-up experiments. The evaluation for the two approaches will be compared providing insight of the main differences.
This AIR is arranged in the following two sections: 2E - thermodynamic characteristics of working fluids, which contains thermodynamic diagrams for a number of working fluids currently in use and supplied by various industrial firms; and 2F - properties of heat transfer fluids, which contains data, primarily in graphical form, on fluids that are frequently used in fluid heat transfer loops. Other properties of the environment, gases, liquids, and solids, can be found, as follows, in AIR 1168/9: 2A-Properties of the natural environment; 2B-Properties of gases; 2C-Properties of liquids and 2D- Properties of solids.
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.
Abstract The vehicle air-conditioning system has significant impact on fuel economy and range of electric vehicles. Improving the fuel economy of vehicles therefore demand for energy efficient climate control systems. Also the emissions regulations motivate the reduced use of fuel for vehicle's cabin climate control. Solar heat gain of the passenger compartment by greenhouse effect is generally treated as the peak thermal load of the climate control system. Although the use of advanced glazing is considered first to reduce solar heat gain other means such as ventilation of parked car and recirculation of cabin air also have impetus for reducing the climate control loads.
Abstract There are some problems “windows fog up a lot” for ventilation system. We have Test Development Procedure to prevent the fog problems. But, Many fog problems occurred in the cars that we made. So in this paper, new ventilation system is needed and developed. The Smart Ventilation System automatically controls indoor air quality even though the blower motor is off. There are two sensors that is used for AutoDefogSensor system and CO2 CONTROL system.. The sensor is on when blower motor and heater control is off. We use these signals and make new ventilation logics. We evaluate this system in chamber & '13 winter test in USA.
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 . 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.
Investigation of Effect of Change in Engine Characteristics and Transfer Path on Passenger Cabin Noise Contributed by Transmission
Abstract 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 (material property) on the NVH performance of the gearbox and subsequently the NVH performance of vehicle.
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.
Abstract 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.
Abstract This paper discusses various fruitful iterations / experiments performed to reduce air flow induced noise without compromising on total air flow requirement for thermal comfort and ways to avoid heat ingress inside the bus. Also the paper discusses the devised process for noise reduction through front loading of computer aided engineering and computational fluid dynamics analysis. Air conditioning buses in light commercial vehicle (LCV) segment is growing market in India, especially for applications like 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 40 seats) with the conditioned air. This makes air conditioning duct design simple and commercially viable.