Due to the increasing computational power, significant progress has been made over the past decades when it comes to CAD, multibody and simulation software. The application of this software allows to develop products from scratch, or to investigate the static and dynamic behavior of multibody models with remarkable precision. In order to keep the development costs low for highly sophisticated products, more precisely motorcycle rider assistance systems, it is necessary to focus extensively on the virtual prototyping using different software tools. In general, the interconnection of different tools is rather difficult, especially when considering the coupling of a detailed multibody model with a simulation software like MATLAB Simulink. The aim of this paper is to demonstrate the performance of a motorcycle rider assistance algorithm using a cosimulation approach between the free multibody software called FreeDyn and Simulink based on a sophisticated multibody motorcycle model.
The aim of the presented research is to propose and benchmark two brake models, namely the novel dynamic ILVO model and a neural network based regression. These can estimate the evolution of the brake friction between pad and disc under different load conditions, which are typically experienced in vehicle applications. The research also aims improving the knowledge of the underlying mechanism related to the evolution of the BLFC (boundary layer friction coefficient), the reliability of virtual environment simulations to speed up the product development time and reducing the amount of vehicle test in later phases and finally improving brake control functions. With the support of extensive brake dynamometer testing, the proposed models are benchmarked against State-of-the-Art. Both approaches are parametrised to render the friction coefficient dynamics with respect to the same input parameters.
Brakes are the most important safety device in a vehicle, however there are few barriers to manufacture, import, or sell friction materials in most of the countries, including USA. European countries, with the ECE R90 program, are a big exception. International Transport Forum published in 2016 the “Benchmarking of road safety in Latin America” report, it mentions that worldwide 17.5 people in every 100,000 die in road accidents, however Andean countries mortality rate is 23.4 and South American 21.0, considerably higher than the worldwide average.
Effective cooling of a heated brake system is critical for vehicle safety and reliability. While some flow devices can redirect airflow more favorably for convective cooling, such a change typically accompanies side effects, such as increased aerodynamic drag and inferior control of brake dust particles. The former is critical for fuel efficiency while the latter for vehicle’s soiling and corrosion as well as non-exhaust emissions. These competing objectives are assessed in this study based on the numerical simulations of an installed brake system under driving conditions. The thermal behavior of the brake system as well as aerodynamic impact and brake dust particle deposition on areas of interest are solved using a coupled 3D transient flow solver, PowerFLOW. Typical design considerations related to enhanced brake cooling, such as cooling duct, wheel deflector, and brake air deflector, are characterized to evaluate the thermal, aerodynamic and soiling performance targets.
The particulate emissions of two brake systems where characterized in a dilution tunnel optimized for PM10 measurements. The larger of them employed a fixed caliper (FXC) and the smaller one a floating caliper (FLC). Both used ECE brake pads of the same lining formulation. Measured properties included gravimetric PM2.5 and PM10, Particle Number (PN) concentrations of both untreated and thermally treated (according to exhaust number regulation) particles using Condensation Particle Counters (CPCs) having 23 and 10 nm cut-off sizes, and an Optical Particle Sizer (OPS). The brakes were tested over a novel test cycle developed from the database of the Worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). A series of WLTP tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. Selected tests were also performed over a short version of the Los Angeles City Cycle.
The absence of combustion engine noise pushes increasingly attention to the sound generation from other, even much weaker, sources in the acoustic design of electric vehicles. The present work focusses on the numerical computation of flow induced noise, typically emerging in components of flow guiding devices in electro-mobile applications. The method of Large-Eddy Simulation (LES) represents a powerful technique for capturing most part of the turbulent fluctuating motion, which qualifies this approach as a highly reliable candidate for providing a sufficiently accurate level of description of the flow induced generation of sound.
Over the past decade, there have been many efforts to generate engine sound inside the cabin either in reducing way or in enhancing way. To reduce the engine noise, the passive way, such as sound absorption or sound insulation, was widely used but it has a limitation on its reduction performance. In recent days, with the development of signal processing technology, ANC (Active Noise Control) is been used to reduce the engine noise inside the cabin. On the other hand, technologies such as ASD (Active Sound Design) and ESG (Engine Sound Generator) have been used to generate the engine sound inside the vehicle. In the last ISNVH, Hyundai Motor Company newly introduced ESEV (Engine Sound by Engine Vibration) technology. This paper describes the ESEV Plus Minus that uses engine vibration to not only enhance the certain engine order components but reduce the other components at the same time. Consequently, this technology would produce a much more diverse engine sound.
The acoustic trim components play an essential role in Noise, Vibration and Harshness (NVH) behavior by reducing both the structure borne and airborne noise transmission while participating to the absorption inside the car and the damping of the structure. Over the past years, the interest for numerical solutions to predict the noise including trim effects in mid frequency range has grown, leading to the development of dedicated CAE tools. Finite Element (FE) models are an established method to analyze NVH problems. FE analysis is a robust and versatile approach that can be used for a large number of applications, like noise prediction inside and outside the vehicle due to different sources or pass-by noise simulation. Typically, results feature high quality correlations. However, future challenges, such as electric motorized vehicles, with changes of the motor noise spectrum, will require an extension of the existing approaches.
Autonomous vehicles must guarantee safety in all road conditions, including driving on wet roads. Aquaplaning (or hydroplaning) is a phenomenon known since the beginning of automotive history, never solved by an active safety system. Currently, no countermeasure system on the market is able to effectively counteract aquaplaning: ABS, ESP or TCS are still inefficient in overcoming this situation. Latest statistical data confirm that the higher percentage of accidents, injuries and deaths are caused by wet road conditions. The aquaplaning happens when the water on the road is too much and the tires start to float causing the instantaneous loss of control. Such phenomenon occurs in human-driven vehicles, with the responsibility of the driver, but in autonomous vehicles (e.g. Level 5), the responsibility for the safety depends on the car and the reduction of the speed is not a solution.
Over the past few decades, the world is looking for a better replacement option for metals. Polymers with reinforcements are finding their way deep inside in most of the engineering application because of its lightweight and superior properties. The aim of this study is to investigate hybrid polymer composite polyphthalamide (PPA) reinforced with glass fibre and Poly tetra fluro ethylene. The reinforcement was varied as 10, 20, 30wt% of Glass Fibre, while fixed quantity of Poly tetra fluro ethylene (PTFE) as 5wt % was taken for hybrid composites preparation. The virgin and hybrid composite specimen were prepared under optimal process parametric conditions through the use of injection moulding techniques and test samples were produced as per ASTM standards. The response of physical properties such as density and various Mechanical testing like Hardness, Tensile Strength, impact and flexural test were carried out and noted.
In this paper the heat transfer coefficient and the heat transfer rate of a heat exchanger is scrutinized by using nanofluids. The silicon carbide nanoparticles, milled and sonificated as nanofluidsof volume fractions 0.01499(%) and 0.01399(%).The heat transfer characteristics of SiC(P)/water, SiC(M)/water, SiC(P)/EG, SiC(M)/EG are measured in a concentric tube heat exchanger under laminar flow condition. The consequence of nanoparticle physiognomies, Reynolds number, on the heat transfer characteristic is scrutinized.It has been found that the addition of milled nanoparticlein the base fluids enhances the heat transfer characteristics rather than the normal nanoparticle. The experimental results shows that the heat transfer characteristicsof SiC(M) is higher than that of SiC(P) in both the case of water and EG. This is because of the structural changes of SiC-M by the deformation caused by the ball milling
Aerodynamic CFD simulations are effectively used to cut down the vehicle development period and to completely understand the aerodynamic effects on vehicle performance. Attaching add-on devices to improve aerodynamic performance is the approach which is highly followed. While the methodologies are well established to quantify the effect of add-on device on improving drag coefficient of a vehicle, the investigations still require in depth understanding, even though a vast number of studies available on aerodynamic drag performance improvement. Front air-dam is one of the components attached below the front bumper to reduce airflow towards underbody and away from front tires, to reduce drag coefficient. However, the size and position of front air-dam must be optimized to get the desired result. Extensive iterations are carried out to finalize the front air-dam size and position until the target is achieved.
Anaerobic digestion of textile wastes under mesophilic conditions were conducted in batch mode with aim of investigating the bio-methane evolution with an initial solid mass of cow dung – 2 kg, cotton and water in 3:1 ratio and press mud is use in the ratio 3:1 with water were evaluated subsequently for 7 weeks (42 days).The highest production of biogas is noted as 3 m3 in fourth week and the higher production of biogas due to press mud is noted as 0.49 in the fifth week.Carbon dioxide is produced as bi product in this bio digestion process. Highest production rate of methane,biogas and carbon dioxide are in their fourth week. Through this experiment 65%-75% of bio gas is collected by the fourth week.
Mobility performance prediction models for tracked vehicles are well established as seen from the literature reviews. However, these simulation models are more suitable for commercial vehicle applications than for military vehicles which operate under wide range of terrain conditions and hostile environment. Most of the models do not take into account the effect of cooling fans, soft ground rolling resistance and torque converter to predict mobility, and therefore using them for military vehicles would pose vital problems and not yield the expected results. This paper attempts to address these problems by using a MATLAB/SIMULINK model, which takes into account these factors for a 65 tonne Main Battle Tank (MBT) as a case study. A simulation model for the above vehicle was developed incorporating effects of cooling fan and torque converter. The results were validated with published trial data for an in-service Main Battle Tank of the same weight class.
Aerodynamics is the study of the effects of air when in motion. The vehicle aerodynamics have become crucial since have realized its importance. This study has been focused on optimizing the aerodynamics with means of adding external aerodynamic component. A custom built multi-axle commercial vehicle (CV) model is subjected to aerodynamic modification and optimized. The components are modified to their optimum size, angle and shape to achieve the best to reduce the drag coefficient, and enhance better performance. The physical appearance of the custom built multi-axle commercial vehicle model has been given keen significance while designing the external devices. All the analysis and modifications have been tried out computationally in the CFD software “ANSYS Fluent” and the CAD modeling in “Creo Parametric”.