Public awareness regarding pollutants and their adverse health effects has created an urgent need for engineers to better understand the combustion process as well as the pollutants formed as by-products of that process. To effectively contribute to emission control strategies and design and develop emission control systems and components, a good understanding of the physical and mathematical principles of the combustion process is necessary. This seminar will bring issues related to combustion and emissions "down to earth," relying less on mathematical terms and more on physical explanations and analogies.
The advent of digital computers and the availability of ever cheaper and faster micro processors have brought a tremendous amount of control system applications to the automotive industry in the last two decades. From engine and transmission systems, to virtually all chassis subsystems (brakes, suspensions, and steering), some level of computer control is present. Control systems theory is also being applied to comfort systems such as climate control and safety systems such as cruise control or collision mitigation systems.
An efficient, robust, and quiet running drivetrain is as essential to customer satisfaction as styling and interior creature comforts. In this seminar, you will be exposed to various methods that can be used to accomplish this goal. Designed to help you visualize both individual components and the entire drivetrain system - without reference to complicated equations - this seminar focuses on the terms, functions, nomenclature, operating characteristics and effect on vehicle performance for each of the drivetrain components.
Newly manufactured light-duty hybrid and electric passenger vehicles must comply with FMVSS 141 minimum sound requirements to reduce the risk of crashes with blind and visually impaired pedestrians. Commercial vehicles operate in a variety of noise-critical environments, from densely packed industrial yards to congested urban areas, making safe electric vehicle operation around pedestrians and bystanders vital. Though the market share of medium and heavy-duty hybrid and electric vehicles is projected to increase annually, there are currently no North American regulations specifically for minimum sound emissions of hybrid and electric vehicles heavier than 10,000 lb GVWR. The primary intent of this paper is to investigate the efficacy and limitations of the current FMVSS 141 requirements when applied to a heavy-duty electric truck.
E-Axle (electric drive axle) system has the advantages of environmental protection and fuel saving, which is one of the main development directions of power train for light buses today, and its NVH (Noise、Vibration、Harshness) performance is receiving more and more attention. In this paper, the whine noise of light buses during acceleration is studied. Firstly, by establishing the noise spectrum analysis method, the main problems of the vehicle are identified as motor whine noise and reducer whine noise. Next, under the condition of ensuring motor performance and low cost, the gas tightness and sound insulation path optimization method of the vehicle is proposed to solve the motor whine noise. At the same time, starting from the research of gear micro modification, and establishing the gear production and assembly process optimization technology to control the reducer whine noise. Finally, the whine noise is optimized by about 8 dB (A).
NVH (Noise, Vibration and Harshness) of the electric drive axle (EDA) is a key attribute in electric-vehicle development. The NVH level of the EDA directly determines the driving comfort and customer feeling of the vehicle. Especially in pure electric models, the EDA noise is more prominent without the engine noise masking. The paper aimed at the problem of the 380±50Hz resonance band on the commercial EDA and caused abnormal noise inside the vehicle. Adopted modal analysis, MASTA simulation, modulation noise analysis and exchange parts DOE, gradually refined the source of the problem to a single part, and finally locked to the source of gear parameters Rs and Fr. By adjusting the production process of gear and the second shaft, the assembly process error was avoided, and the gear parameter targets are formulated.
HVAC system design plays an important role in the acoustic comfort of passenger vehicles and becomes prominent in electric vehicles. In the case of buses, cabin volume is larger than in cars, thus HVAC system required inside buses are bigger in size, and to meet comfort requirement numerous blowers are used for airflow delivery. Due to multiple blowers rotating inside the mixing unit and large delivery of air inside of the large HVAC system airborne noise is produced during its operations. One way to evaluate this airborne noise with CFD methods would be using the traditional sliding mesh approach around all the blowers to resolve the flow and turbulence, which is computationally very expensive. However, ability to predict noise inside the bus cabin with lesser turnaround time is important to accommodate quick design changes at early product development stage.
Engineering of solutions for vibration challenges consists of several steps. Each of them needs different methods, for most steps, several approaches are valid. This work describes an efficient way to get from customer requirements via computational methods, experimental tests and lifetime calculations to a suitable product. The example is a metal cushion molded from wire mesh, used as a spring-damper system. Metal cushions for vibration isolation are used where high dynamic stresses occur or the environmental conditions overwhelm rubber solutions. Progressive nonlinear stress-deflection behavior and the high damping offer advantages for a wide range of applications. Here, a vibration problem in a suspension of an electrical drive is solved. The application is a commercial vehicle that is used in a city cycle. Customer requirements gained from measurements describe the geometrical boundaries as well as the loads and needed isolation frequency for acoustical improvement.
cellcentric – a joint venture of Daimler Truck AG and the Volvo Group AB formed in 2021 - develops, produces and commercializes fuel-cell systems for use in heavy-duty trucks and other applications. Its ambition is to become a leading global manufacturer of fuel-cells, and thus help the world take a major step towards climate-neutral and sustainable transportation by 2050. In this presentation, Lars Johansson, COO of cellcentric, will introduce into the fuel cell technology and leads through the company’s journey from the first prototypes to the planned mass production.
Electric trucks that use fuel cells to generate on-board power are seen as the cornerstone of zero-carbon, zero-emission long-haul heavy-duty transportation. Modularization of fuel cell stacks, components and systems is critical for rapid market entry and lower total cost of ownership. To achieve this, efficient development processes must be utilized to handle the large variety of applications and use cases with reduced engineering effort. The goals can be achieved with model-based development across the entire development chain. This publication presents such a holistic model-based process that extends from the fuel cell powertrain level through the system level to the component level. This process is closely interlinked to the thermal integration, the function development of the hybrid system as well as the fuel cell system of the vehicle via the use of model-in-the-loop approaches.
Presenting the Volvo transition development work towards carbon neutral products, focused on fuel cell electric vehicle development. Discussing and reflecting on the growth of hydrogen infrastructure and hydrogen storage. Exemplifying with development examples, challenges as well as need of firm standards, policies and economic stability.
There is potential to reduce GHG emissions in the HDV sector through different powertrain options (electric batteries, fuel cell batteries, and combustion engines), and different fuel or energy choices (hydrogen, biofuels, natural gas). The climate impacts of these technologies and fuels vary over the lifetime of the vehicle model. From extracting and processing raw materials to operation and maintenance, some powertrain options are more energy intensive to build than their counterparts, and some fuel sources can produce higher emissions during their production or use. The study uses a life-cycle assessment to analyze the options to allow policymakers and manufacturing companies to compare which powertrain and fuel options provide the largest GHG emissions reductions.
The current decade is seeing rapid changes in heavy duty powertrains. All manufacturers at IAA were proposing solutions that support a carbon neutral future. Battery Electric (BEV) or hydrogen either in the form Fuel Cell (FCEV) or Internal Combustion Engines (H2-ICE) are being seen as the most exciting options currently. This presentation focuses in on emissions control of H2-ICE systems. Emissions control of H2-ICE requires close consideration of current and future legislation, as well as meeting new and unique challenges to deliver a sustainable zero carbon solution that the planet requires. H2-ICE SI engines can operate as stoichiometric or lean burn, the direction of emissions control can be chosen based on this. System components need to consider other factors such as possible H2 embrittlement, oil bypass, other legislative criteria emissions, global warming potential (GWP) as well as higher levels of water in the exhaust from H2 combustion.