CONVERSION for WAR - Influence of Automotive Mass-Production Methods

<div class="htmlview paragraph">Several years ago some of the most prominent leaders in automotive industries cooperated to form a purely engineering group that had as its primary purpose developing a type of rigid-airship construction in which the public would have confidence. It was conceived that such an airship should be</div> <div class="htmlview paragraph"> <ol class="list nostyle"> <li class="list-item"> <span class="li-label">(1)</span> <div class="htmlview paragraph">Fireproof</div> </li> <li class="list-item"> <span class="li-label">(2)</span> <div class="htmlview paragraph">Weatherproof</div> </li> <li class="list-item"> <span class="li-label">(3)</span> <div class="htmlview paragraph">Durable and permanent in structure</div> </li> <li class="list-item"> <span class="li-label">(4)</span> <div class="htmlview paragraph">Navigable in practically all kinds of weather</div> </li> <li class="list-item"> <span class="li-label">(5)</span> <div class="htmlview paragraph">Economical in the use of buoyant gas and ballast</div> </li> </ol> </div> <div class="htmlview paragraph">To meet all of these requirements it was decided, after mature consideration, that a substantially all-metal construction was imperative. Development of the Metalclad airship has now reached a point where the general soundness of the design seems fully assured as</div> <div class="htmlview paragraph"> <ol class="list nostyle"> <li class="list-item"> <span class="li-label">(1)</span> <div class="htmlview paragraph">The structural and aerodynamic efficiencies have been established by both analytical and experimental methods</div> </li> <li class="list-item"> <span class="li-label">(2)</span> <div class="htmlview paragraph">The technical problems involved in the construction have been mastered to a certainty hitherto unapproached in any new design</div> </li> <li class="list-item"> <span class="li-label">(3)</span> <div class="htmlview paragraph">The general design of an airship of demonstration size, 200,000 cu. ft. or one-tenth the size of the Shenandoah, has been completed</div> </li> <li class="list-item"> <span class="li-label">(4)</span> <div class="htmlview paragraph">Full-sized structural members of every part of the framework have been built and tested to destruction revealing that the minimum safety factor is double that of the Shenandoah. The longitudinal strength of the metal hull will be more than four times as great as that of the Shenandoah</div> </li> <li class="list-item"> <span class="li-label">(5)</span> <div class="htmlview paragraph">The problem of riveting the metal hull-plating has been solved through the perfection of an automatic riveting-machine</div> </li> <li class="list-item"> <span class="li-label">(6)</span> <div class="htmlview paragraph">The problem of making the metal hull gas-tight has been solved with surprising efficiency indicating an osmosis of about one-tenth that through gold-beaters skin and only one-hundredth that through rubberized fabric</div> </li> <li class="list-item"> <span class="li-label">(7)</span> <div class="htmlview paragraph">A suitable coating to prevent corrosion has been satisfactorily tested</div> </li> <li class="list-item"> <span class="li-label">(8)</span> <div class="htmlview paragraph">A source of supply of aluminum alloys of dependable quality is assured</div> </li> <li class="list-item"> <span class="li-label">(9)</span> <div class="htmlview paragraph">Shop facilities for fabrication are available in Detroit</div> </li> <li class="list-item"> <span class="li-label">(10)</span> <div class="htmlview paragraph">Skilled metal-workers familiar with aluminum and its alloys are at hand</div> </li> </ol> </div> <div class="htmlview paragraph">These results depend upon certain fundamental principles that are described in the paper. In effect, the design is an entirely new one, but adheres to the fundamental unalterable principles underlying all sound engineering-work.</div> <div class="htmlview paragraph">The paper states that the Metalclad airship is the last step in the development of rigid airships and most certainly must be adopted if such a means of transportation is to be made available both for the arms of National Defense and for commercial purposes.</div> <div class="htmlview paragraph">Appendices that include extracts from studies and texts arranged to illustrate the subject matter in the main paper and furnish food for discussion supplement the paper. This material is partially elementary in form as limitations of space preclude any attempt at completeness.</div>

<div class="htmlview paragraph"><b>W</b>E are in a new era of production that has been made possible by the broader vision of the production engineer, who is now an established factor in industry because of the demand for reduced production costs. The two factors over which he has control are labor and machinery. Labor cost is of diminishing significance as machinery takes over an increasing proportion of the responsibility for performance.</div> <div class="htmlview paragraph">To the two production principles of the division of labor and the transfer of skill to machinery is added a third principle deduced from facts observed in modern production practice. This principle is integrated production, the combining of work units, which are the smallest possible divisions into which operations are broken down by the time-study man, so that a number of identical or similar operations are performed simultaneously by multiple tools, with the maximum efficiency and economy for each tool or each work unit.</div> <div class="htmlview paragraph">This calls for increasingly greater refinement, from multiple tooling to provision for performing at one time operations governed by differing conditions. It can be carried to any extent justified by resulting economy. The point at which economy ceases to increase is determined by calculating carrying charges on the equipment against the operating cost of production. On greater quantities, as refinement is carried to greater limits, the savings in each case become less; the economy curve flattens out considerably long before “mass production” is reached.</div> <div class="htmlview paragraph">Integrated production also combines the division of labor, the transfer of intelligence to machines, and the simultaneous performance of work units in a way to comprise a complete process or method performed in the shortest possible time. This results in smaller inventories of raw materials and materials in process, greater flexibility in the manufacturing process, quicker turnover from raw material to finished product, shorter financing periods, less money required and less tied up in forms subject to loss. Such savings, on a National scale and in the volume represented by the automotive industry, must contribute to the present favorable financial situation. Thus the production engineer is an important factor in such an ultimate phenomenon as the National prosperity of the Country.</div> <div class="htmlview paragraph">In the discussion one member tells how “simultation” with multiple-head machines made possible in 6 years a reduction of incandescent-lamp factories from 10 to 3 and of direct-labor operatives from 4500 to 1500 with a simultaneous increase in production of 62.5 per cent. Other points brought out are that economical production can be obtained in a period of reduced schedule by keeping all the machines in a group running but reducing their speed and reducing the number of operators; that cost can be reduced by putting money into machinery and reducing the labor-cost; that there is economy in setting the equipment for a production a little greater than the planned quantity; and that there is a critical point at which the cost per piece becomes greater with the simple machine than with the more refined and more expensive machine and at which a change in method should be made.</div>

<div class="htmlview paragraph">The intensive endeavor of the human, to do research work and to test in the low earth orbit, results in complex orbital platforms. These space based platforms are either permanent or retrievable. This is the case of the European Retrievable Carrier (EURECA), a free-flying reusable platform that is launched and retrieved by the NSTS Orbiter. The first EURECA mission will be primarily a microgravity mission specifically for material processing and life science payloads.</div> <div class="htmlview paragraph">The thermal control system of EURECA has to ensure the correct environment for the carrier and the payload, throughout all mission phases, by means of passive and active means. The passive means consist of various multi-layer insulations, surface finishing, conducting straps. Electrical heaters work, in conjunction with the active cooling loop, to keep the spacecraft temperature at adequate level. The cooling loop consists of a single phase Freon 114 pumped loop, with two radiators in parallel. The possibility to accommodate different payload heat dissipations is ensured also by the capability of the system to bypass one of the two radiators.</div> <div class="htmlview paragraph">The degree of on-board autonomy required for EURECA, mainly due to the very short ground contact periods, necessitates a sophisticated control of the thermal functions performed by a dedicated on-board computer.</div> <div class="htmlview paragraph">The thermal control of EURECA is believed to be a good example of the System Thermal Control of today, which means a maximum of flexibility in the development, manufacturing and operation. This is required for the high density, complex structure, different mission profiles, considerations of retrieval capability, adaptation of future payloads and take over of non-thermal related tasks of today's spacecraft's.</div> <div class="htmlview paragraph">This paper deals both with the development and verification of the thermal control system design and with its operational aspects.</div> <div class="htmlview paragraph">In addition examples are given to show how the model development, the implementation of the different requirements and the design solutions are made, in case of problems not solvable by the affected subsystems alone, namely:</div> <div class="htmlview paragraph"> <ul class="list disc"> <li class="list-item"> <div class="htmlview paragraph">Missing power interface for a payload in some mission cases</div> </li> <li class="list-item"> <div class="htmlview paragraph">Electronic design problem of the 20 N thruster chamber temperature monitoring</div> </li> <li class="list-item"> <div class="htmlview paragraph">High temperature of the battery due to specification problems</div> </li> <li class="list-item"> <div class="htmlview paragraph">Power shortage during operational phase</div> </li> </ul> </div> <div class="htmlview paragraph">The paper is completed by a critical review (lesson learned) of the performed System Thermal work, in which the authors give also some suggestions for improvements.</div>

<div class="section abstract"><div class="htmlview paragraph"><b>Background</b>: The Indian automobile industry, including the auto component industry, is a significant part of the country’s economy and has experienced growth over the years. India is now the world’s 3<sup>rd</sup> largest passenger car market and the world’s second-largest two-wheeler market. Along with the boon, the bane of road accident fatalities is also a reality that needs urgent attention, as per a study titled ‘Estimation of Socio-Economic Loss due to Road Traffic Accidents in India’, the socio-economic loss due to road accidents is estimated to be around 0.55% to 1.35% of India’s GDP [<span class="xref">27</span>] Ministry of road transport and highways (MoRTH) accident data shows that the total number of fatalities on the road are the highest (in number terms) in the world. Though passenger car occupant fatalities have decreased over the years, the fatalities of vulnerable road users are showing an increasing trend. India has committed to reduce road fatalities by 50% by 2030. In this context, the automotive industry as well as MoRTH have been taking multiple initiatives including those related to vehicular and road engineering as well as educational measures for raising awareness in the field of road safety.</div><div class="htmlview paragraph">With the intent of lowering road traffic accidents, the government and the ministry are constantly upgrading the requirements related to vehicles, infrastructures, and their implementation thereof. In this context, various future regulations are being deliberated. One such regulation in discussion pertains to requirements for the protection of the passenger car occupants in the event of a full-frontal collision with a focus on restraint systems (AIS 201). This will push manufacturers to design more sophisticated restraints that would help to reduce restraint-induced injuries. The draft version of the standard is available for public input/ discussion.</div><div class="htmlview paragraph">The key objective of the study documented herein is to consider various aspects of the draft standard (AIS 201) from the Indian perspective. This study investigates the research questions, enumerated below: <ol class="list nostyle"><li class="list-item"><span class="li-label">1</span><div class="htmlview paragraph">What should be the appropriate test speed for the full-frontal test based on Indian accident data?</div></li><li class="list-item"><span class="li-label">2</span><div class="htmlview paragraph">What is the suitable dummy configuration in terms of gender, seating position, and age to maximize occupant safety in full frontal accidents?</div></li><li class="list-item"><span class="li-label">3</span><div class="htmlview paragraph">Is the proposed ATD’s anthropometry (weight and height) suitable, based on the people involved in full frontal cases in India?</div></li><li class="list-item"><span class="li-label">4</span><div class="htmlview paragraph">What are occupant injury attributes in full-frontal accidents?</div></li></ol></div><div class="htmlview paragraph"><b>Key findings/ expected research findings</b>: India has a very different mix of road traffic users and road traffic fatalities compared to that in Europe (Refer to <span class="xref">Table 1</span>). Further, issues like seat belt usage are of utmost concern. The demographic for India is also very different from those of developed economies. With India being a country with a rather young population, male and female dummies for driver and front passenger positions should be looked upon. This calls for India-specific safety regulations and research work on automotive test dummies.</div><div class="htmlview paragraph"><b>Practical implications</b>: The study can potentially provide a suggestion for alignment of the regulatory requirements with the actual situations, thereby increasing the effectiveness of the standard.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Vibration testing is an essential component of automotive product development, ensuring that components such as engines, transmissions, and electronic systems perform reliably under various operating conditions. The adoption of electronics in the automotive industry, particularly during the 1950s and 1960s, marked a shift in vibration testing approaches, moving from primarily low-frequency tests to methods that could address high-frequency vibrations as well. This evolution highlights the need for effective vibration fixture designs that can simulate real-world conditions, enabling manufacturers to detect potential weaknesses before products are integrated into vehicles. A key aspect of vibration testing is the identification of resonant frequencies within components. The coupled mass-spring-damper system, for example, can exhibit multiple resonances characterized by a Bode Diagram, where the Q factor technique is utilized to assess damping levels. Accurate vibration analysis can be achieved through various methodologies, including modal analysis and frequency response calculations, which help engineers understand how components will behave under different stimulus.</div><div class="htmlview paragraph">Furthermore, the use of advanced analytical tools, such as Finite Element Analysis (FEA) has become increasingly important in the automotive industry. These modern approaches allow for more precise and efficient vibration analysis, providing deeper insights into potential issues and enhancing overall product reliability.</div><div class="htmlview paragraph">By adhering to industry standards such as International Organization for Standardization standard i.e. (ISO) 16750-3, Society of Automotive Engineers standard i.e. (SAE) J1455, and Military standard (MIL-STD)-810G, manufacturers can ensure their products meet rigorous safety and durability requirements, ultimately leading to reduced warranty claims and increased customer satisfaction.</div><div class="htmlview paragraph">Utilizing FEA allows for virtual prototyping, which reduces the reliance on physical prototypes traditionally used to test and refine designs. This approach not only shortens the design-to-production cycle but also allows for comprehensive testing and optimization, ultimately resulting in a more efficient development process and lower costs associated with prototype creation.</div><div class="htmlview paragraph">The design process for vibration fixtures involves a cyclical approach where simulations guide modifications. By continuously analysing and adjusting designs based on performance data, engineers can refine fixtures to meet specific criteria such as cost efficiency, structural performance, and overall functionality. This iterative nature of design helps in exploring multiple configurations and ensuring that the final product achieves all desired performance targets within the constraints of the given package space.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Fatigue fractures are the most common type of mechanical failures of components and structures. It is widely recognized that surface finish has a significant effect on fatigue behavior. Forgings can be accompanied by significant surface roughness and decarburization. The correction factors used in many mechanical design textbooks to correct for the as-forged surface condition are typically based on data published in the 1940's. It has been found by several investigators that the existing data for as-forged surface condition is too conservative. Such conservative values often result in over-engineered designs of many forged parts, leading not only to increased cost, but also inefficiencies associated with increased weight, such as increased fuel consumption in the automotive industry. In addition, this can reduce forging competitiveness as a manufacturing process in terms of cost and performance prediction in the early design stage, compared to alternative manufacturing processes. In this paper two surface conditions are evaluated, a smooth-polished surface finish to be used as the reference surface and a hot-forged surface finish, in order to quantify forged surface finish effect at several hardness levels (19 HRC, 25 HRC, 35 HRC and 45 HRC) on bending fatigue of a commonly used forged steel (10B40).</div></div>

<div class="section abstract"><div class="htmlview paragraph">The increasing adoption of battery electric vehicles (BEVs), driven by the EU's target of no internal combustion engine vehicles from 2035 onwards, is driving significant changes in the automotive industry. However, the high degree of electrification and the unique low-speed acceleration behavior of BEVs therefore lead to new challenges. Measuring the drivetrain power and efficiency in a reproducible way and obtaining meaningful results is one of the challenges.</div><div class="htmlview paragraph">To address this challenge, a novel test method is developed that offers a simple and preferably modification-free approach to drivetrain power and efficiency measurements for BEVs, allowing for efficient and reproducible testing. Different paths for determining the drivetrain power with varied measurement efforts are presented and evaluated. The test method is designed to provide reliable and accurate results for BEVs.</div><div class="htmlview paragraph">In this study, the effectiveness of the test method is shown by presenting the results of tests conducted with a VW e-up! on a Vehicle-in-the-Loop test bench and comparing them with data from previous studies. The results show that this approach offers a reproducible and meaningful way to measure power and efficiency in BEV’s drivetrains.</div><div class="htmlview paragraph">In addition to the discussion of the results, insights into the measurement of BEV’s drivetrains are given. An outlook on future challenges and how to overcome these with the help of the presented test bench as well as the knowledge gained from the study completes the paper.</div><div class="htmlview paragraph">Overall, the study offers insights into the development and testing of BEVs, providing a robust and reliable test method.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Vehicle dynamics encompasses a vehicle’s motion along three principal axes: longitudinal, lateral, and vertical. The vertical component is particularly susceptible to vibrational forces that can impair passenger comfort and overall performance, and the suspension system filters these vibrations. Engineers and designers conduct various studies to enhance quality and develop innovative designs in this context.</div><div class="htmlview paragraph">However, when it comes to military vehicles, this system is often treated as classified. Consequently, the proposed work aims to determine the parameters of this system for a wheeled military vehicle with four axles. To achieve this, a mathematical model is proposed utilizing the concepts of power flow and kinematic transformers through a modular system, intended to serve as the foundation for solving an inverse problem to identify these parameters.</div><div class="htmlview paragraph">This approach employs two stochastic methods, particle swarm optimization (PSO) and differential evolution (DE), and field tests to collect real data from the vehicle. Following the parameter estimation, a comparison between the numerical simulation and the actual dynamic behavior of the vehicle is proposed. Based on these tests, the system is analyzed under several proposed configurations.</div></div>

<div class="htmlview paragraph">Due to the requirements of the market, engine manufacturers and their suppliers must develop new products in a short lead time, with high quality, high reliability and lowest possible costs.</div> <div class="htmlview paragraph">A method to obtain a short lead time for a complicated aluminum cylinder head is the design in 3 D CAD and the use of simultaneous engineering.</div> <div class="htmlview paragraph">A practical example shows the design of a 16-valve cylinder head in 3 D CAD (Catia).</div> <div class="htmlview paragraph">The cylinder head supplier received a CAD-tape with the main dimensions such as valve locations, shape of the combustion chamber and ports and location of the bolts.</div> <div class="htmlview paragraph">A design team completed the cylinder head design in 3 D CAD in consideration of the needs for foundry technology, casting tool design and machining of the part.</div> <div class="htmlview paragraph">Special casting tools for the prototyping were manufactured parallel to the cylinder head design.</div> <div class="htmlview paragraph">It is shown, that by the use of 3 D CAD/CAM and simultaneous engineering the multitude of engineering tasks can be solved and prototypes delivered within 3 months.</div>

<div class="htmlview paragraph">Full service supply and concurrent engineering are the wave of the future in powertrain development. Launching a new automotive engine requires a fast and efficient development program for both the first engine and the transition into mass production. This paper presents a case study utilizing Soligen's Direct Shell Production Casting (DSPC <sup>®</sup>) to integrate the development of a new aluminum intake manifold and the launch of the mass production tooling, eliminating long lead times and costs as well as potential geometrical inconsistencies from incongruous manufacturing phases.</div> <div class="htmlview paragraph">DSPC is a rapid casting process which makes conventional prototype casting obsolete. DSPC works by producing ceramic casting molds with integral cores, directly from CAD files without the need for patterns and core boxes. Using DSPC in the design phase enables engineers to test multiple design iterations in various alloys concurrently, expediting and improving the design phase. Additionally, DSPC's reliance on CAD files provides for stringent configuration control, assuring that all design changes are properly documented.</div> <div class="htmlview paragraph">In the transition to mass production, the CAD files of the approved cast parts are converted into production tooling CAD files and subsequently cast as net shape tools. Working with the mass production foundry, these tools are launched onto the production lines. In this way, Soligen manages the maintenance of part continuity, accuracy and timeliness.</div> <div class="htmlview paragraph">The case study in this paper describes a manifold launch with permanent molds for annual production of 1,000,000 manifolds. The whole process was paperless and driven by the CAD file (prototypes, gating simulation, permanent (steel) molds and core boxes, and final machining).</div> <div class="htmlview paragraph">By basing all production on the CAD file and DSPC technology, a smooth and cost effective transition from prototype to mass production could be guaranteed. This successful transition has proven to shorten time-to-market and dramatically Improve profitability.</div>

<div class="htmlview paragraph">Dowty Aerospace was faced with the problems of maintaining high output at low cost. Production schedules did not allow delays in required plating. With the plating shop located remote from the production area, it was apparent some action had to be taken to insure increased workloads could continue to be met within the scheduled timeframe.</div> <div class="htmlview paragraph"><b>DOWTY AEROSPACE IS A WORLD LEADER</b> in aerospace and defense systems engineering. Dowty companies are well known for the manufacturer of landing gears, propellers, engine fuel controls, flying controls, avionics, general hydraulics, seals, electronic controls and communications. In addition to this manufacturing, Dowty offers repair, overhaul, test and support facilities in all these fields. Dowty also provides full support for other manufacturer's equipment. </div> <div class="htmlview paragraph"> <div class="graphic-wrapper"><img class="article-figure figure" src="890931_fig0001.jpg" alt="No Caption Available"/></div> </div> <div class="htmlview paragraph">Dowty Aerospace Corporation, Product Support Division is located in Sterling, Virginia approximately five miles north of Dulles International Airport. This location includes the corporate offices, equipment and product support for repair and overhaul of components of some 40 different aircraft.</div> <div class="htmlview paragraph">The Dowty plating shop was located in leased facilities approximately seven miles from Corporate headquarters. The leased facilities were not conductive to efficient process layout and utilization for plating. All plating tanks sat on the floor resulting in uneven lip height based on depth of tank. The lack of an overhead material handling system created inefficient parts handling requirements and separation of the plating facility from the machining operation increased transportation costs.</div> <div class="htmlview paragraph">While the quality of plating was excellent and careful planning and coordination allowed meeting production schedules, future growth and flexibility could best be met with the plating shop located closer to the machine shop facilities.</div>

<div class="section abstract"><div class="htmlview paragraph">The objective of this study was to investigate which of the artificial aging cycles available in the automotive industry that causes major deactivation of three-way catalysts (TWCs) and can be used to obtain an aged catalyst similar to the road aged converter (160 000km).</div><div class="htmlview paragraph">Standard bench cycle (SBC) aging with secondary air injection (SAI) covered aging with various mass flows - a flow from three cylinders into one catalyst system and a flow from three cylinders into two parallel connected catalysts. For rapid catalyst bench aging, secondary air injection is a very efficient tool to create exotherms. Furthermore, the effect on catalytic activity of SAI aging with poisons from oil and fuel dopants (P, Ca, Zn) was investigated.</div><div class="htmlview paragraph">The catalysts were thoroughly characterized in light-off and oxygen storage capacity measurements, emission conversion as a function of lambda and load variation was determined. These catalysts were then compared to three-way catalysts aged on an engine bench comparing two fuel-cut (FC) strategies, i.e. fuel-cut retardation (FCR) and fuel-cut acceleration (FCA) [<span class="xref">1</span>].</div><div class="htmlview paragraph">For 40-hour aged samples, SAI aged had the highest total deactivation of the catalytic system. The fuel-cut aging also showed significant deactivation but not to the same extent as the SAI aging cycle. This result can be explained by the different pattern of exotherms and the magnitude of the temperature excursions. The total temperature rise in fuel-cut aging cycles was lower than for SAI aged and which resulted in less sintering of the catalytic washcoat. For the fuel-cut ageing systems the exotherms were growing with the ageing time. This was verified by resulting light-off and oxygen storage capacity (OSC) results.</div></div>

<div class="htmlview paragraph">The car manufacturing process benefits from a competition between different materials that have to fulfil such demands as lightweight, comfort and safety. For ecological and economical reasons low vehicle weights minimise the energy consumption necessary for transportation.</div> <div class="htmlview paragraph">High strength steels enable to lower body weight by reducing sheet thickness and increase car safety by excellent crash behaviour. A very important contribution to vehicle safety and value maintenance during the whole life cycle is the use of galvanised steel sheets to prevent corrosion and premature failure of crash relevant body components.</div> <div class="htmlview paragraph">Up to date the high standards in corrosion protection and appearance of the exposed car body in the automotive industry are verified by extensive surface coating processes, applied to the body in white by batch processes. Continuous coil coating of galvanised sheet steel is an extremely efficient alternative to the currently used surface finishing processes. The range of possible coil-coating systems expands from spot weldable thin film coatings over EDP-replacements to complete body paints.</div> <div class="htmlview paragraph">Thin film precoated, galvanised steel sheets are comparably or easier to process in terms of formability and weldability as well as adhesive joining than their uncoated counterparts. Furthermore they yield better application properties like enhanced corrosion protection, especially in cavities. This results in a possible elimination of secondary corrosion protection measures and leaner production processes. Thus, by avoiding, or shifting environmentally sensitive processes to the steel supplier it is possible to slim down the production efforts for high quality automotive vehicles.</div> <div class="htmlview paragraph">Precoated steel sheets offer a high potential to optimise car production in terms of environmental aspects and economical benefits.</div>

<div class="section abstract"><div class="htmlview paragraph">In recent years the automotive industry has been using an increasing number of high powered engines with fewer cylinders, with the goal to reduce weight and fuel consumption and hence to achieve lower CO2 emissions. In the following paper, an overview about the currently existing methods and products within the exhaust development is given which follow automotive lightweight trend.</div><div class="htmlview paragraph">Continuous innovations in new materials, structural design and manufacturing process as well as mastering the integration of the components and modules within the system with a thorough understanding and optimization of the system behavior is enabling the reduction of weight in exhaust system.</div><div class="htmlview paragraph">Another possibility to reduce the weight is the use of additional components such as valves. In the following, a discussion about the different types of valves is presented. These valves can be implemented within the exhaust system in order to bring a constraint in the system and consequently additional acoustic damping.</div><div class="htmlview paragraph">Due to engine downsizing, many premium vehicles lost their class-representing sound signature. An active system can be used in order to enhance the sound according to the customer demands. In addition to that, an active system can help reducing muffler volume.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Over the past few decades, there has been a notable increase in stakeholder’s attention on Earth's climate. The automotive industry, being a major contributor to this phenomenon, has been endeavoring to mitigate its impact through various measures. These efforts include reducing emissions in existing internal combustion engine (ICE) vehicles and promoting electric vehicles (EVs) as a feasible alternative for consumers. Despite these initiatives, there remains a persistent challenge in improving the fuel economy and driving range of vehicles.</div><div class="htmlview paragraph">India, located along the Tropic of Cancer, experiences both tropical and subtropical climates. As a result, a substantial portion of the total heat absorbed is from solar radiation. The higher heat load necessitates extensive use of air conditioning (AC) systems, which significantly contributes to the overall power consumption of vehicles. Various measures are being implemented to mitigate this heat load and enhance the efficiency of AC operations. This study aims to investigate the properties of different types of photochromatic glass and their effects on cabin heat load. Various proposals involving solar-coated glass, including absorptive and reflective types as well as combinations of these types are examined. Digital simulations are conducted to identify the most suitable alternatives for glass and their combinations.</div><div class="htmlview paragraph">In this study, a combination of the Lattice-Boltzmann (LBM) based Power FLOW solver and the Finite Element based solver is utilized to simulate long transient soak and cool down processes. Furthermore, human thermal physiology is incorporated into the model to account for subjective evaluations of the in-cabin thermal environment. The Berkeley Comfort Model library, available in software, is employed for this purpose. This model addresses vasodilation and vasoconstriction effects based on external ambient conditions, as well as the influence of clothing and passenger metabolic rate. Digital simulations indicate that solar-coated reflecting-type glasses exhibit promising results.</div><div class="htmlview paragraph">The mentioned glass is installed in vehicles, and various trials are conducted under different conditions, including highway cycles, city cycles, and range trials, in both moderate and severe ambient conditions. Temperatures inside the cabin, at the grill level, and at most of touch points including glass surface are recorded for trials. The rate of rise of temperature during soaking reduced by ~15-18 % at cabin level and by ~32-35 % on touchpoints. In the vehicle-level test results, it is observed that touch point temperatures decrease by ~11-12°C, and air conditioning power consumption reduced by ~9-13%.</div></div>