Structural Design Considerations for Bonded Aluminum Structured Vehicles

<div class="htmlview paragraph">The 1980 requirements for bumpers limit the damage that may be sustained in 8 km/h (5 mph) pendulum and barrier impacts. This paper covers four items of interest for design of one-piece aluminum bumpers: (1) properties of alloys, (2) dent resistance, (3) beam strength, (4) relative behavior of aluminum and steel.</div> <div class="htmlview paragraph">Static and dynamic tests are used to define the effects of yield strength and thickness on denting. Finite element calculations agree well with the results of dynamic bending tests of bumpers. Data presented also show that the strain rates during beam bending are low. Relative weights of aluminum and steel bumpers are defined.</div>

<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="section abstract"><div class="htmlview paragraph">Evolving fuel efficiency and emissions standards, along with consumer demand for performance, are strong pressures for light-weighting of performance oriented motorcycles. The field of topology optimization (TO), with the extension of multi-material topology optimization (MMTO) provide manufacturers with advanced structural light-weighting methodology. TO methodology has been adopted in many industries, including automotive where light-weighting assists in meeting efficiency regulations. The development of process specific manufacturing constraints within MMTO is a critical step in increasing adoption within industries dealing with manufacturing cost restrictions. This capability can decrease design complexity, lowering manufacturing costs of optimization solutions.</div><div class="htmlview paragraph">A conventional all-aluminum perimeter style motorcycle chassis is analyzed to develop baseline compliance (total strain energy) metrics. An MMTO design space is created and optimized with steel and aluminum, such that results match the baseline design weight. This formulation demonstrates increased structural efficiency through stiffer structures at equivalent weight. Results are generated with standard MMTO, symmetry, and extrusion constraints to demonstrate utility of these manufacturing constraints. Material ratios are used to enforce lower cost material distribution selections.</div><div class="htmlview paragraph">The usage of MMTO with manufacturing and material ratio constraints has resulted in up to 60.4% reduction in structural compliance of designs, and a multitude of lower cost alternative designs. The usage of symmetry constraints provides effectively identical results to standard MMTO, with a computational time reduction of 29%. Extrusion constraints demonstrate decreased manufacturing difficulty with a computational time reduction of 52% and structural performance penalty of 58.6% from the lowest compliance MMTO result. The enforcement of steel has demonstrated a decrease in structural performance (increase in compliance) and material costs, with varying degrees depending on manufacturing constraints and enforcement limits. The MMTO based designs provide a range of solutions to designers, which can be selected based on the importance of structural efficiency, manufacturing difficulty, and material costs.</div></div>

<div class="htmlview paragraph"><b>T</b>HE PAPER urges united cooperation instead of the present division of responsibility between the engine designer and the airplane designer in the installation of aircraft engines. The tubular rings upon which engines are commonly mounted are usually supported by structural members that are welded to the ring and attached to the fuselage at the four longitudinals. Inaccuracy is common in these structures, and many of them lack sufficient stiffness.</div> <div class="htmlview paragraph">Gravity gasoline-feed is recommended for its simplicity, provided the pressure head required by the carbureter can be secured, but the author reports having seen an installation in which the engine would operate so long as the airplane had its tail on the ground, yet the engine would die as soon as the tail was raised during a take-off. The use of gasoline-resisting rubber-hose with metal liners and the avoidance of sharp bends are recommended for the gasoline connections. A strainer of ample capacity with an accessible drain should be located near the carbureter.</div> <div class="htmlview paragraph">The overflow from the pressure-relief valve is reported to be the cause of vapor lock sometimes, when it is merely a return to the pump inlet. The location of oil tanks often is such as to prevent effective cooling, and oil thermometers frequently are located at the engine oil-inlet instead of at the outlet. For new installations, thermometers are recommended to indicate both the inlet and outlet temperatures of the oil.</div> <div class="htmlview paragraph">Too little attention is given to carbureter heating, the author says. The carbureter must be jacketed if warm air is not supplied in sufficient quantity to prevent the formation of ice around the jets and throttle. Other installation details that require more attention are the electric wiring, the engine controls and the cowling.</div> <div class="htmlview paragraph"> <figure id="F1" class="figure"> <div class="graphic-wrapper"><img class="article-figure figure" src="300037_fig0001.jpg" alt="No Caption Available"/></div> </figure> </div> <div class="htmlview paragraph">In the discussion<span class="xref">*</span> it is stated that there has been a constant battle between the Air Corps and the manufacturers to secure uniform and adequate installations. More direct cooperation between the Department of Commerce and the Army and Navy Services is recommended because the latter have learned much that would be of great help to commercial operators. Further discussion has to do with carbureter heating and oil cooling.</div>

<div class="htmlview paragraph">Cost reduction is an essential and continuous process to meet the competitive environment of product pricing and to increase the profitability of an organization. Integrated cost reduction exercise encompass all the possible avenue., e.g. Alternate material & it's procurement system, batch size, material handling, manufacturing process improvements, logistics and finally review & make changes to derive an optimum design and cost reductions to maximum extent.</div> <div class="htmlview paragraph">This paper presents a systematic approach for achieving the cost reduction of an existing 5.7Tonnne LCV truck frame from design consideration. The methodology involves, identification of the components of the frame for the cost reduction, redesign of existing frame compatible to the cost reduction need, preliminary performance evaluation of the present frame and the cost reduction frame, redesign of the frame for the performance, detailed cost evaluation, prototype manufacturing, laboratory testing, vehicle level testing and final release for the mass production. Chassis designers contributed for major design changes to derive maximum cost reduction without compromising durability or performance deterioration due to bending or torsional stiffness changes from existing frame.</div> <div class="htmlview paragraph">After a comprehensive study, it is identified that deletion of the boxing plate and the replacement of the tubular cross members with channel type cross members will contribute for the potential cost savings of the frame. With these inputs concept design of the cost reduction frame is arrived.</div> <div class="htmlview paragraph">The important performance characteristics of a chassis frame are structural integrity (Strength and Stiffness) and durability. The existing and the cost reduction frames are evaluated based on these performance characteristics.</div> <div class="htmlview paragraph">The final design of the cost reduction frame is arrived based on CAE analysis of the frame for structural integrity, Number of iterative operations got eliminated due to the use of multidisciplinary optimization (MDO) package. Different load cases which focus on strength and stiffness of the frame are considered as an example.</div> <div class="htmlview paragraph">Bending and torsional stiffness of the existing and the cost reduction frames are also measured in the test rig. It is found that bending stiffness of the cost reduction frame is 9.15% more than the existing frame and torsional stiffness of the cost reduction frame is closer to the existing frame. It was also found that the durability of the existing and the cost reduction frame in bending is almost same. The test specifications are arrived based on strain measurements on the existing frame in our torture track.</div> <div class="htmlview paragraph">The above methodology helped us in deriving a estimated cost saving of Rs.311/- by the modified frame design. There are other intangible benefits like savings in labour cost due to elimination of the boxing plate, savings in the processing cost of boxing plate welding etc. The estimated cost savings is likely to be double of the above amount and would result in 3.5% of the Chassis frame aggregate cost.</div>

<div class="section abstract"><div class="htmlview paragraph">This paper details the methodology used to prevent Thermal events in a vehicle at design and development stages which can lead to vehicle fire or Thermal events. Vehicle Safety is always been in prime focus for designers while introducing newer products in markets for the customers. It is now common to see vehicles catching on fire in 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. So the most critical area where Thermal event can take place are under hood which includes the complete engine compartment and under body. The extent of fire depends on the fire source, characteristics of the materials used in constructing and furnishing the vehicle.</div><div class="htmlview paragraph">The Performance and life of Electronic parts and parts made of polymeric materials such as rubber and plastics which in result are greatly influenced by the temperature of their surroundings. Different materials have different sensitivities to temperature and decomposition processes will differ substantially from case to case. High temperatures, hot surfaces and a variety of combustible materials make the engine compartment and under body high fire risk areas. Under these scenarios it is important for any vehicle designer to consider the hazards associated with fire and choose the materials appropriately for avoiding and minimizing the fires to pose less risk to the occupants. In this paper the possible fire sources, combustible material in vehicles and considerations in design for minimizing the risks related to fire and Thermal safety are detailed taking into account the hazards associated and risk assessment.</div></div>

For decades, structural design has erroneously been taught to architecture students using a modified version of an engineering-based pedagogical model. Instead of imparting a broad range of information for how structural design considerations could be critically integrated into architectural design, these courses instead focus on a narrow range of curricular topics and analytical methods that negatively impact the preparedness of architectural students for practice. To help address these deficiencies, the entire building technology course sequence at Iowa State University, has been dramatically reconfigured as a collaborative and integrative teaching environment that uses active learning environments and unique classroom activities to enhance student learning. Specifically this paper will present three different labs that occur during the final five-week course module of this structural design sequence. Each of the three exercises demonstrates particularly important, capstone-level, learning objectives. The paper will describe the means, methods, challenges, and benefits of these specific assignments and how these represent other important improvements throughout the new sequence. Examples of student work will be shown, and an assessment of the efficacy of the assignments will be presented including reflections upon lessons learned and suggestions for future improvements. INHERENT INEFFECTIVENESS Effectively teaching structural design to architecture students is an important, but complicated process. At its most basic level, architectural education teaches ways to create accommodating and experiential spaces and forms, yet the extent of possible responsive solutions requires the coalescence of a multiplicity of diverse cultural, aesthetic, and technological considerations. Although design is a reiterative process that rarely has a single correct or obvious answer, there are aspects, like structural design, that do require quantifiable verification for viability. Therefore, designing requires an ability to experiment and evaluate different arrangements and assembly options using both qualitative and quantitative analytical means and objectives. Learning these different skills can be complex and confusing, especially because these skills are frequently taught quite differently. Unfortunately, for the last fifty years, structural design has been predominantly taught to architecture students in a manner more in line with an engineering education. By continuing to base the course content and pedagogical approach primarily on calculation-based means of analytics and evaluations practiced by the engineers,

<div class="section abstract"><div class="htmlview paragraph">The introduction of the Worldwide Harmonised Light Vehicles Test Procedure (WLTP) and Real Driving Emissions (RDE) test requirements have put increased strain on vehicle and engine performance as well as the development of advanced engine technologies and emissions mitigation strategies. This requirement for increased development is a direct result of the need for new vehicles to comply with present and emerging emissions standards across an extended range of boundary conditions that include ambient temperature, altitude and driving style.</div><div class="htmlview paragraph">To reduce the significant number of on-road test permutations that would ordinarily be required to validate a given vehicle across the defined RDE boundary conditions, a Road to Rig (R2R) development approach known as RDE Plus (RDE+) is being evolved at HORIBA MIRA. This will enable real world driving scenarios to be developed and deployed much further upstream during the development lifecycle of the vehicle and engine using aspects of virtual calibration; the aim being to significantly reduce vehicle and engine development costs and associated timescales.</div><div class="htmlview paragraph">On-road RDE data is presented in this paper from vehicles of different powertrain technologies gathered from several European test locations under conditions representing the boundaries defined by the RDE protocol. Upon gathering a combination of vehicle CANBus, custom instrumentation and emissions (Portable Emissions Measurement System (PEMS)) data, recorded RDE routes were replicated on a chassis dynamometer with a view of developing a standardised practical approach to replicate RDE tests in the laboratory environment.</div><div class="htmlview paragraph">Lab tests were performed at HORIBA MIRA in the Advanced Emissions Test Centre (AETC) with the aim of defining a chassis dynamometer test methodology suitable for different powertrain technologies that results in accurate representations of on-road conditions with respect to vehicle load, ambient temperature, altitude and emissions.</div><div class="htmlview paragraph">Following the road to chassis dynamometer correlation, the vehicle engines will be installed on an engine dynamometer with the objective of developing a suite of “worst case” RDE cycles using an Engine-in-the-Loop (EiL) format complemented with a Design of Experiments (DoE) type mapping approach. These “worst case” cycles, most likely operating near to or at the RDE boundary condition limits, can then be adopted for engine and vehicle development purposes as well as providing evidence of complete RDE compliance. The methodology to develop this EiL strategy in combination with a detailed overview of RDE+ project as a whole is presented in this paper.</div></div>

<div class="section abstract"> <div class="htmlview paragraph">This Recommended Practice provides a procedure for measuring and documenting the aerodynamic performance in a full-scale wind tunnel of passenger vehicles, i.e., mass-produced cars and light-duty trucks intended primarily for individual consumers. Testing or numerical modeling of pre-production and/or reduced-scale models is outside the scope of this document. Aerodynamic <i>development</i> procedures, i.e., methods to improve or optimize aerodynamic performance, are also excluded.</div> <div class="htmlview paragraph">It is well-known that aerodynamic performance results depend significantly on vehicle content and loading, as well as the wind tunnel itself (type, scale, and simulation qualities of the wind tunnel). Publication of non-standard test results causes unnecessary additional development work and incorrect perception of a vehicle’s anticipated aerodynamic performance by government, academia, and the general public.</div> <div class="htmlview paragraph">The intent of this document is to promote uniformity and traceability of published aerodynamic performance data acquired in a wind tunnel, thereby enhancing the public reputation and credibility of the aerodynamics discipline in the total vehicle development process.</div> <div class="htmlview paragraph">Measurement of the aerodynamic performance according to this Recommended Practice requires a full-scale wind tunnel test on a production-ready, full-scale vehicle according to specifications for vehicle loading, content, and wind tunnel conditions.</div> <div class="htmlview paragraph">The measurement and resulting documentation for a particular vehicle shall be reported only by the company that intends to produce the vehicle. Whenever there is an opportunity for interpretation of the document, a good faith effort shall be made to obtain the vehicle’s typical in-service performance and avoid finding the best possible performance under the best possible circumstances.</div> <div class="htmlview paragraph">Use of and compliance with this Recommended Practice is voluntary; however, it is mandatory for those advertising or otherwise publishing aerodynamic performance as “measured according to SAE J2881.” Conversely, any advertised or otherwise published result carrying this or a substantially similar designation must have the necessary documentation accepted by and on file with the SAE in accordance with the procedures defined in this Recommended Practice.</div> <div class="htmlview paragraph"><span class="xref">Appendices B</span> and <span class="xref">C</span> contain the necessary submittal documents for compliance with this Recommended Practice. When a submittal is made, the chairman of the Road Vehicle Aerodynamics Forum Committee (RVAC) or his/her designee shall review the submittal for proper completion according to the requirements herein, but without consideration of the technical merit of the claimed performance. After the chairman’s review, SAE will maintain an electronic database of all submittals.</div> <div class="htmlview paragraph">The database shall be available only to members and liasion members of the RVAC. Any RVAC member who retrieves information from the database shall do so with the understanding that the information is to be considered confidential within his or her company.</div></div>

<div class="htmlview paragraph">From time to time, over many years, MIRA (the Motor Industry Research Association) has carried out surveys of the handling behaviours of various classes of road vehicles. The most recent investigation has concerned modern European intercity buses, or coaches as they are termed in Britain.</div> <div class="htmlview paragraph">The work was sponsored by the British Government together with five vehicle manufacturers who each supplied one bus. The main aim of the work was to ascertain the handling characteristics of a sample of modern buses in terms of both absolute behaviour and relative behaviour compared to other classes of road vehicles. However, the manufacturers sponsoring the work were also very interested to discover any correlation between various features of layout of the vehicles and the handling characteristics.</div> <div class="htmlview paragraph">To quantify the vehicle behaviours, MIRA used the test and data analysis techniques it had developed with other classes of road vehicles, techniques which have been incorporatedinto ISO standard procedures.</div> <div class="htmlview paragraph">The paper presents the more important handling characteristics of the fully laden buses, together with some typical results for other classes of road vehicles. The findings of the work may be summarised as follows:</div> <div class="htmlview paragraph"> <ol class="list nostyle"> <li class="list-item"> <span class="li-label">1.</span> <div class="htmlview paragraph">By using “state-of-the-art” bus design it has been possible to improve the handling characteristics of heavy vehicles;</div> </li> <li class="list-item"> <span class="li-label">2.</span> <div class="htmlview paragraph">In the context of heavy vehicle behaviour, the handling characteristics of the modern buses tested are good;</div> </li> <li class="list-item"> <span class="li-label">3.</span> <div class="htmlview paragraph">It has been possible to correlate some features of bus design and layout to their handling responses.</div> </li> </ol> </div>

<div class="htmlview paragraph">Adhesive bonding of automotive plastics is an area that will receive increasing attention in the future. Many rigid and flexible plastic substrates are being used today in the manufacture of automobiles. Many new materials (RIM, RRIM, Polyester composites, ABS, polyolefins) are being considered in the replacement of standard automotive metals. The considerations of weight reduction, corrosion resistance, design possibilities and production improvements are obvious.</div> <div class="htmlview paragraph">Our discussion of Adhesive Bonding Technology & Applications will include: <ol class="list nostyle"> <li class="list-item"> <span class="li-label">(a)</span> <div class="htmlview paragraph">Engineering adhesives to structurally bond rigid plastics to themsleves and metals.</div></li> <li class="list-item"> <span class="li-label">(b)</span> <div class="htmlview paragraph">General Adhesives to bond flexible plastics to rigid plastics or metals.</div></li> <li class="list-item"> <span class="li-label">(c)</span> <div class="htmlview paragraph">Thermoplastic Adhesives to bond a variety of specialty plastics.</div></li></ol></div> <div class="htmlview paragraph">The general performance capabilities for each Adhesive System will be presented and typical applications discussed. It is proposed that the data will allow one to make sound decisions in the area of matching adhesives and applications in bonding of automotive plastics.</div>

<div class="section abstract"><div class="htmlview paragraph">As the emissions and fuel economy standards for internal combustion engines become ever more stringent, a variety of valvetrain control methods have been developed to improve engine performance. One of these is camshaft (CAM) phasing, which controls the angular position of the CAM relative to the crankshaft allowing changes to the timing of valve lift events. This method has demonstrated advantages including broadening the engine torque curve, increasing peak power at higher RPM, reducing hydrocarbon and NOx emissions, and improving fuel economy. In addition, external EGR systems can be eliminated because internal cylinder dilution control can be achieved by varying CAM timing.</div><div class="htmlview paragraph">Current implementations of CAM phasing use oil-pressure-based electro-mechanical systems. While these systems are relatively low cost and have proven to be robust, they have disadvantages at low oil temperatures and pressures (such as during cranking events). To overcome performance issues of oil based systems, Delphi has created a CAM phasing system using a brushless DC (BLDC) motor to drive the phasing mechanism. This approach provides full control independent of oil conditions and demonstrates increased phasing authority.</div><div class="htmlview paragraph">This paper will describe the electronics and algorithms required to control the three-phase BLDC motor which is part of the electric variable CAM phasing (eVCP) system. This controller takes desired CAM phase angle as an input, calculates the phase angle error, and closes the loop on the resultant motor current command. The electronics are packaged in a production-style case suitable for use in customer development applications.</div><div class="htmlview paragraph">From a software perspective, this paper will discuss architecture considerations, including provisions for model-based rapid algorithm development and low-level motor control functions. Hardware component selection criteria and electromagnetic compatibility (EMC) design considerations will also be included. Finally, motor performance test data will be presented.</div></div>

<div class="htmlview paragraph">In comparison with current production diesel engines the next generation will need to have better fuel consumption, lower noise and reduced emissions both gaseous and visible.</div> <div class="htmlview paragraph">Research over the last ten years has shown that higher rates of injection, coupled with a sharp end of injection and precise timing control will give considerable benefits.</div> <div class="htmlview paragraph">The Lucas CAV response to this requirement is the development of an electronically controlled unit injector system which provides these characteristics.</div> <div class="htmlview paragraph">This paper describes the operating principles and looks at the main performance parameters, including design considerations for continuous operation at pressures up to 1500 Bar.</div> <div class="htmlview paragraph">As the unit injector is a new concept to many engine manufacturers, Lucas CAV has developed a suite of computer programmes to assist in the design and engine application process in terms of a complete hydraulic simulation, unit injector drive train analysis and cam design.</div>

<div class="section abstract"><div class="htmlview paragraph">In the pursuit of carbon emission reduction, hybridization has emerged as a significant trend in powertrain electrification. As a crucial aspect of hybrid powertrain system development, achieving high brake thermal efficiency (BTE) and a wide operating range with high efficiency are essential for hybrid engines to effectively integrate with the hybrid system.</div><div class="htmlview paragraph">When developing dedicated hybrid engines (DHE), several design considerations come into play. First, in order to make efficient use of available resources and enable engine production on the same assembly line as conventional engines, it is crucial to maintain consistency in key design parameters of the cylinder head and block, thus extending the platform-based design approach. Among the key measures to achieve high BTE, cooled exhaust gas recirculation (EGR) has been extensively explored and proven effective in improving efficiency by mitigating knocking and reducing engine cooling heat loss. Fast combustion, acting as a facilitator, becomes crucial for the system to handle high EGR rates. Therefore, a high-tumble combustion system design is required as an integral part of the hybrid engine to promote rapid combustion.</div><div class="htmlview paragraph">Optimizing the gas exchange system is another crucial aspect in achieving high brake thermal efficiency. Investigation results indicate that through system optimization and trade-offs, optimal matches can be found among EGR rate, cam duration, and compression ratio for a hybrid engine. Furthermore, by optimizing energy management strategy with the hybrid system, the engine operates under high-efficiency regions for the majority of the WLTC test cycle, resulting in reduced fuel consumption.</div><div class="htmlview paragraph">This paper describes the evolution of combustion system design from conventional engines to DHE at SAIC Motor, and presents investigations into the impact of key technical measures on brake thermal efficiency. It also explores the optimization of energy management strategies and their effect on engine operating conditions and fuel consumption of the hybrid vehicle in the WLTC cycle.</div></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>