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Viewing 181 to 210 of 33398
2017-09-04
Technical Paper
2017-24-0179
Marco Tonetti, Giorgio Rustici, Massimo Buscema, Luca Ferraris
Abstract Final Euro6d emission legislation with the new homologation cycle and Real Driving Emission requirements has set a strong challenge for the ICE Passenger Car applications. Thanks to their well-known low fuel consumption characteristics, Diesel Engines can play a key role for the fulfillment of the European 2020 CO2 fleet target but need to confirm their capability to fully control noxious emissions even in extreme operating conditions, while restraining the overall engine costs and complexity. CO2 and NOx emissions reduction are considered the main drivers for diesel engine evolution. In this perspective, Exhaust Gas After-treatment and Combustion System have been identified as the two main technology aspects to be developed. The purpose of this paper is to describe the evolution paths of these two technologies and the results achieved so far in terms of noxious emissions reduction.
2017-09-04
Technical Paper
2017-24-0009
Federico Millo, Giulio Boccardo, Andrea Piano, Luigi Arnone, Stefano Manelli, Giuseppe Tutore, Andrea Marinoni
Abstract To comply with Stage IV emission standard for off-road engines, Kohler Engines has developed the 100kW rated KDI 3.4 liters diesel engine, equipped with DOC and SCR. Based on this engine, a research project in collaboration between Kohler Engines, Ricardo, Denso and Politecnico di Torino was carried out to exploit the potential of new technologies to meet the Stage IV and beyond emission standards. The prototype engine was equipped with a low pressure cooled EGR system, two stage turbocharger, high pressure fuel injection system capable of very high injection pressure and DOC+DPF aftertreatment system. Since the Stage IV emission standard sets a 0.4 g/kWh NOx limit for the steady state test cycle (NRSC), that includes full load operating conditions, the engine must be operated with very high EGR rates (above 30%) at very high load.
2017-09-04
Journal Article
2017-24-0057
Roberto Finesso, Omar Marello, Ezio Spessa, Yixin Yang, Gilles Hardy
Abstract A model-based approach to control BMEP (Brake Mean Effective Pressure) and NOx emissions has been developed and assessed on a FPT F1C 3.0L Euro VI diesel engine for heavy-duty applications. The controller is based on a zero-dimensional real-time combustion model, which is capable of simulating the HRR (heat release rate), in-cylinder pressure, BMEP and NOx engine-out levels. The real-time combustion model has been realized by integrating and improving previously developed simulation tools. A new discretization scheme has been developed for the model equations, in order to reduce the accuracy loss when the computational step is increased. This has allowed the required computational time to be reduced to a great extent.
2017-09-04
Journal Article
2017-24-0072
Gabriele Di Blasio, Carlo Beatrice, Giacomo Belgiorno, Francesco Concetto Pesce, Alberto Vassallo
Abstract The paper describes the challenges and results achieved in developing a new high-speed Diesel combustion system capable of exceeding the imaginative threshold of 100 kW/l. High-performance, state-of-art prototype components from automotive diesel technology were provided in order to set-up a single-cylinder research engine demonstrator. Key design parameters were identified in terms boost, engine speed, fuel injection pressure and injector nozzle flow rates. In this regard, an advanced piezo injection system capable of 3000 bar of maximum injection pressure was selected, coupled to a robust base engine featuring ω-shaped combustion bowl and low swirl intake ports. The matching among the above-described elements has been thoroughly examined and experimentally parameterized.
2017-09-04
Journal Article
2017-24-0104
Daniel M. Nsikane, Kenan Mustafa, Andrew Ward, Robert Morgan, David Mason, Morgan Heikal
Abstract The Direct Numerical Simulation (DNS) approach to solving the fundamental transport equations down to the smallest scales of motion is favorable should the requirement be a truly predictive solution of fluid dynamic problems, but the simulation run times are unacceptable for most practical industrial applications. Despite the steadily increasing computational capabilities, Reynolds Averaged Navier-Stokes (RANS) based frameworks remain the most commercially viable option for high volume sectors, like automotive. The sub models within RANS simplify the description of key physical phenomena and include several numerical constants. These so-called “tuning constants” introduce multivariable dependencies that are almost impossible to untangle with local sensitivity studies.
2017-09-04
Journal Article
2017-24-0157
Wolfgang Gross, Ahmad Rabanizada, Konstantin Markstädter, Harald Stoffels, Michael Bargende, Adrian Rienäcker
Abstract High combustion pressure in combination with high pressure gradient, as they e.g. can be evoked by high efficient combustion systems and e.g. by alternative fuels, acts as broadband excitation force which stimulates natural vibrations of piston, connecting rod and crankshaft during engine operation. Starting from the combustion chamber the assembly of piston, connecting rod and crankshaft and the main bearings represent the system of internal vibration transfer. To generate exact input and validation values for simulation models of structural dynamic and elasto-hydrodynamic coupled multi-body systems, experimental investigations are done. These are carried out on a 1.5-l inline four cylinder Euro 6 Diesel engine. The modal behaviour of the system was examined in detail in simulation and test as a basis for the investigations. In an anechoic test bench airborne and structure-borne noises and combustion pressure are measured to identify the engine´s vibrational behaviour.
2017-09-04
Journal Article
2017-24-0159
Davide Di Battista, Marco Di Bartolomeo, Carlo Villante, Roberto Cipollone
Abstract Internal combustion engines are actually one of the most important source of pollutants and greenhouse gases emissions. In particular, on-the-road transportation sector has taken the environmental challenge of reducing greenhouse gases emissions and worldwide governments set up regulations in order to limit them and fuel consumption from vehicles. Among the several technologies under development, an ORC unit bottomed exhaust gas seems to be very promising, but it still has several complications when it is applied on board of a vehicle (weight, encumbrances, backpressure effect on the engine, safety, reliability). In this paper, a comprehensive mathematical model of an ORC unit bottomed a heavy duty engine, used for commercial vehicle, has been developed.
2017-09-04
Journal Article
2017-24-0001
Alexander Fandakov, Michael Grill, Michael Bargende, Andre Casal Kulzer
Abstract The most significant operation limit prohibiting the further reduction of the CO2 emissions of gasoline engines is the occurrence of knock. Thus, being able to predict the incidence of this phenomenon is of vital importance for the engine process simulation - a tool widely used in the engine development. Common knock models in the 0D/1D simulation are based on the calculation of a pre-reaction state of the unburnt mixture (also called knock integral), which is a simplified approach for modeling the progress of the chemical reactions in the end gas where knock occurs. Simulations of thousands of knocking single working cycles with a model representing the Entrainment model’s unburnt zone were performed using a detailed chemical reaction mechanism. The investigations showed that, at specific boundary conditions, the auto-ignition of the unburnt mixture resulting in knock happens in two stages.
2017-09-04
Journal Article
2017-24-0012
Andrea Piano, Giulio Boccardo, Federico Millo, Andrea Cavicchi, Lucio Postrioti, Francesco Concetto Pesce
Abstract Nowadays, injection rate shaping and multi-pilot events can help to improve fuel efficiency, combustion noise and pollutant emissions in diesel engine, providing high flexibility in the shape of the injection that allows combustion process control. Different strategies can be used in order to obtain the required flexibility in the rate, such as very close pilot injections with almost zero Dwell Time or boot shaped injections with optional pilot injections. Modern Common-Rail Fuel Injection Systems (FIS) should be able to provide these innovative patterns to control the combustion phases intensity for optimal tradeoff between fuel consumption and emission levels.
2017-09-04
Journal Article
2017-24-0041
Daniele Piazzullo, Michela Costa, Luigi Allocca, Alessandro Montanaro, Vittorio ROCCO
Abstract During gasoline direct injection (GDI) in spark ignition engines, droplets may hit piston or liner surfaces and be rebounded or deposit in the liquid phase as wallfilm. This may determine slower secondary atomization and local enrichments of the mixture, hence be the reason of increased unburned hydrocarbons and particulate matter emissions at the exhaust. Complex phenomena indeed characterize the in-cylinder turbulent multi-phase system, where heat transfer involves the gaseous mixture (made of air and gasoline vapor), the liquid phase (droplets not yet evaporated and wallfilm) and the solid walls. A reliable 3D CFD modelling of the in-cylinder processes, therefore, necessarily requires also the correct simulation of the cooling effect due to the subtraction of the latent heat of vaporization of gasoline needed for secondary evaporation in the zone where droplets hit the wall. The related conductive heat transfer within the solid is to be taken into account.
2017-09-04
Journal Article
2017-24-0043
Thomas Kammermann, Jann Koch, Yuri M. Wright, Patrik Soltic, Konstantinos Boulouchos
Abstract The interaction of turbulent premixed methane combustion with the surrounding flow field can be studied using optically accessible test rigs such as a rapid compression expansion machine (RCEM). The high flexibility offered by such a test rig allows its operation at various thermochemical conditions at ignition. However, limitations inherent to such test rigs due to the absence of an intake stroke do not allow turbulence production as found in IC-engines. Hence, means to introduce turbulence need to be implemented and the relevant turbulence quantities have to be identified in order to enable comparability with engine relevant conditions. A dedicated high-pressure direct injection of air at the beginning of the compression phase is considered as a measure to generate adjustable turbulence intensities at spark timing and during the early flame propagation.
2017-09-04
Journal Article
2017-24-0014
Fabio Bozza, Vincenzo De Bellis, Pietro Giannattasio, Luigi Teodosio, Luca Marchitto
Abstract The technique of liquid Water Injection (WI) at the intake port of downsized boosted SI engines is a promising solution to improve the knock resistance at high loads. In this work, an existing 1D engine model has been extended to improve its ability to simulate the effects of the water injection on the flame propagation speed and knock onset. The new features of the 1D model include an improved treatment of the heat subtracted by the water evaporation, a newly developed correlation for the laminar flame speed, explicitly considering the amount of water in the unburned mixture, and a more detailed kinetic mechanism to predict the auto-ignition characteristics of fuel/air/water mixture. The extended 1D model is validated against experimental data collected at different engine speeds and loads, including knock-limited operation, for a twin-cylinder turbocharged SI engine.
2017-09-04
Journal Article
2017-24-0045
Blane Scott, Christopher Willman, Ben Williams, Paul Ewart, Richard Stone, David Richardson
Abstract In-cylinder temperature measurements are vital for the validation of gasoline engine modelling and useful in their own right for explaining differences in engine performance. The underlying chemical reactions in combustion are highly sensitive to temperature and affect emissions of both NOx and particulate matter. The two techniques described here are complementary, and can be used for insights into the quality of mixture preparation by measurement of the in-cylinder temperature distribution during the compression stroke. The influence of fuel composition on in-cylinder mixture temperatures can also be resolved. Laser Induced Grating Spectroscopy (LIGS) provides point temperature measurements with a pressure dependent precision in the range 0.1 to 1.0 % when the gas composition is well characterized and homogeneous; as the pressure increases the precision improves.
2017-08-25
Technical Paper
2017-01-5006
Robert Henneberger, Peter Pfeffer, Marcel Greiner
The ride comfort and safety is largely determined by the tuning of the vehicle suspension dampers. A methodology is developed to identify the influence of road excitation and of the top mounts on the optimal damper setting. Therefore this paper deals with a simulation routine, which minimizes the development effort of body damping systems on automobiles by using an analytical computation method. For this, a partly linear model is examined and evaluated in order to optimize its properties regarding ride comfort and road holding using an extended quarter-car model and a Pareto-chart. The influence of the road excitation level, the top mount and engine mount stiffness on the optimum damper characteristic is shown. This provides the starting point and the range for the tuning sessions during the vehicle development process.
2017-08-25
Technical Paper
2017-01-5007
Jinlun Wang, Zhengwei Ma
Flanging U-shaped piece is a typical auto-body parts, such as tailor-welded front rail inner panel, whereas, large springback amount is a critical challenge in sheet metal forming process, which size and shape accuracy affect the quality of the following assembly process. Firstly, a new form of variable blank holder force (BHF) was proposed in this paper, the springback problem was analyzed by numerical method based on the constant BHF of 90 t, and the contours of von-Mises stress and springback amount were calculated by the dieless method. Secondly, variable BHF with changes in position and punch stroke was designed and used to control springback. Finally, orthogonal experimental and range analysis method were used to optimize the variable BHF parameters. The orthogonal experiment with 5 factors and 4 levels was designed with the initial BHF, the change moment of BHF and the final BHF as variables.
2017-08-18
Journal Article
2017-01-9380
Jan-Hubert Wittmann, Lars Menger
Abstract Current regulatory developments aim for stricter emission limits, increased environmental protection and purification of air on a local and global scale. In order to find solutions for a cleaner combustion process, it is necessary to identify the critical components and parameters responsible for the formation of emissions. This work provides an evaluation process for particle formation during combustion of a modern direct injection engine, which can help to create new aftertreatment techniques, such as a gasoline particle filter (GPF) system, that are fit for purpose. With the advent of “real driving emission” (RDE) regulations, which include market fuels for the particulate number testing procedure, the chemical composition and overall quality of the fuel cannot be neglected in order to yield a comparable emission test within the EU and worldwide.
2017-08-17
Journal Article
2017-01-9683
Rui Ma, John B. Ferris, Alexander A. Reid, David J. Gorsich
Abstract Computationally efficient tire models are needed to meet the timing and accuracy demands of the iterative vehicle design process. Axisymmetric, circumferentially isotropic, planar, discretized models defined by their quasi-static constraint modes have been proposed that are parameterized by a single stiffness parameter and two shape parameters. These models predict the deformed shape independently from the overall tire stiffness and the forces acting on the tire, but the parameterization of these models is not well defined. This work develops an admissible domain of the shape parameters based on the deformation limitations of a physical tire, such that the tire stiffness properties cannot be negative, the deformed shape of the tire under quasi-static loading cannot be dominated by a single harmonic, and the low spatial frequency components must contribute more than higher frequency components to the overall tire shape.
2017-08-01
Journal Article
2017-01-9682
Mohsen Rahmani, Kamran Behdinan
Abstract Widely used in automotive industry, lightweight metallic structures are a key contributor to fuel efficiency and reduced emissions of vehicles. Lightweight structures are traditionally designed through employing the material distribution techniques sequentially. This approach often leads to non-optimal designs due to constricting the design space in each step of the design procedure. The current study presents a novel Multidisciplinary Design Optimization (MDO) framework developed to address this issue. Topology, topography, and gauge optimization techniques are employed in the development of design modules and Particle Swarm Optimization (PSO) algorithm is linked to the MDO framework to ensure efficient searching in large design spaces often encountered in automotive applications. The developed framework is then further tailored to the design of an automotive Cross-Car Beam (CCB) assembly.
2017-07-10
Technical Paper
2017-28-1922
S Nataraja Moorthy, Manchi Rao, Prasath Raghavendran, Sakthi Babu
Abstract NVH is becoming one of the major factor for customer selection of vehicle along with parameters like fuel economy and drivability. One of the major NVH challenges is to have a vehicle with aggressive drivability and at the same time with acceptable noise and vibration levels. This paper focuses on the compact utility vehicle where the howling noise is occurring at higher rpm of the engine. The vehicle is powered by three cylinder turbocharged diesel engine. The noise levels were higher above 2500 rpm due to the presence of structural resonance. Operational deflection shapes (ODS) and Transfer path analysis (TPA) analysis was done on entire vehicle and powertrain to find out the major reason for howling noise at higher engine rpm. It is observed that the major contribution for noise at higher rpm is due to modal coupling between powertrain, half shaft and vehicle sub frame.
2017-07-10
Technical Paper
2017-28-1923
Satish Mudavath, Ganesh Dharmar, Shyam Somani
Abstract Digital human models (DHM) have greatly enhanced design for the automotive environment. The major advantage of the DHMs today is their ability to quickly test a broad range of the population within specific design parameters. The need to create expensive prototypes and run time consuming clinics can be significantly reduced. However, while the anthropometric databases within these models are comprehensive, the ability to position the manikin’s posture is limited and needs lot of optimization. This study enhances the occupant postures and their seating positions, in all instances the occupant was instructed to adjust to the vehicle parameters so they were in their most comfortable position. While all the Occupants are accommodated to their respective positions which finally can be stacked up for space assessments. This paper aims at simulating those scenarios for different percentiles / population which will further aid in decision making for critical parameters.
2017-07-10
Technical Paper
2017-28-1931
Shaul Hameed Syed, K Rameshkumar
Abstract In this work an attempt is made to design and fabricate a low cost dynamometer for measuring cutting forces in three directions in a CNC vertical milling machine. The dynamometer is designed and fabricated to withstand load up to 5000 N along ‘X’, ‘Y’ and ‘Z’ axis. Milling dynamometer developed in this work, consists of four octagonal rings as an elastic member on which strain gauges are mounted for measuring the cutting forces. Suitable materials for the fixture and for the octagonal rings are chosen for constructing the dynamometer. Structural analysis has been carried out to check the safe design of the dynamometer assembly consisting of fixture and the octagonal rings for the maximum loading conditions. Static calibration of the dynamometer is carried out using slotted weight method by simulating the actual conditions. Calibration chart was prepared for three directions by relating load and corresponding strain.
2017-07-10
Technical Paper
2017-28-1930
Anil Kumar Jaswal, Pradeep Chandrasekaran, Surendran Ramadoss
Abstract Indian Automobile Industry has started using Six Sigma for Vehicle Design and process improvement to compete with Global competition. This Paper describes how the Tools of Six Sigma shall be used as an Effective Tool for both redefining the Design and the Process Improvement. This Paper talks on the evolution of DMADV approach in Indian Automobile Industry compared to the related Trends in Other Manufacturing Sectors. The Author describes how the warranty failures in Commercial Segment Vehicle Category which was the selling talk for the Competition was addressed in Leading Indian Automobile OEM. As this Failure was adversely impacting customer satisfaction and no solution seemed forthcoming, top Management indicated to use a radically different approach to solve the problem within a years’ time.
2017-07-10
Technical Paper
2017-28-1935
Vellavedu Velumani Praveen, P Baskara Sethupathi
Abstract Formula SAE is a prestigious engineering design competition, where student team design, fabricate and test their formula style race car, with the guidelines of the FSAE rulebook, according to which the car is designed, for example the engine must be a four-stroke, Otto-cycle piston engine with a displacement no greater than 710cc. According to FSAE 2017 Rule Book [1], ARTICLE 3, IC3.2 and IC3.3 state that the maximum sound level should not exceed 110 dBC at an average piston speed of 15:25 m/s (for the KTM 390 engine, which has 60 mm stroke length, the noise level will be measured at 7500 RPM) and 103 dBC at Idle RPM. So, the active muffler which works as a normal reflective muffler till the 7500 RPM range, after which an electronic controlled throttle mechanism is used to reduce the backpressure (since after 7500 RPM the noise level doesn't matter in FSAE) by using tach signal from the engine to control the throttle (two position).
2017-07-10
Technical Paper
2017-28-1939
Maruti Patil, Penchaliah Ramkumar, Shankar Krishnapillai
Abstract Minimum weight and high-efficiency gearboxes with the maximum service life are the prime necessity of today’s high-performance power transmission systems such as automotive and aerospace. Therefore, the problem to optimize the gearboxes is subjected to a considerable amount of interest. To accomplish these objectives, in this paper, two generalized objective functions for two stage spur-gearbox are formulated; first objective function aims to minimize the volume of gearbox material, while the second aims to maximize the power transmitted by the gearbox. For the optimization purpose, regular mechanical and critical tribological constraints (scuffing and wear) are considered. These objective functions are optimized to obtain a Pareto front for the two-stage gearbox using a specially formulated discrete version of non-dominated sorting genetic algorithm (NSGA-II) code written MATLAB. Two cases are considered, in the first with the regular mechanical constraints.
2017-07-10
Technical Paper
2017-28-1938
Shyam Sunder Manivannan, Gopkumar Kuttikrishnan, Rajesh Siva, Janarthanan C, G A Ramadass
Abstract The hybrid robot will be a battery operated four wheel drive vehicle with a rigid chassis for all terrain operation. The vehicle will be suited for various payloads based on applications with geological, atmospheric sensors and buried object identification at a depth of 8 to 100 m., etc. The vehicle will be remotely controlled through a RF signal, allows it to maneuver up to 5 km. The novelty of the design, is its capability for all terrain and ease of trafficability based on skid steering, self-alignment of sensors and vehicle traction in spite of possible inverted conditions and the vehicle can travel from land, snow, water and vice versa. The vehicle could be deployed for surveying coastline of water bodies, borderlines and also be extensively used in polar region for studying glacier aging and as advance vehicle for the convoys and polar mapping.
2017-07-10
Technical Paper
2017-28-1944
Asif Basha Shaik Mohammad, Ravindran Vijayakumar, Nageshwara Rao Panduranga
Abstract The vibration and acoustic behaviour of the internal combustion engine is a highly complex one, consisting of many components that are subject to loads that vary greatly in magnitude and which operate at a wide range of speeds. The interaction of these components and the excitation of resonant modes of vibration is a major problem for the powertrain engineer when optimising the noise and vibration characteristics of the engine. This paper summarises a study that has been undertaken to assess and optimise the dynamic behaviour of a current production diesel engine with the objective of reducing radiated noise from the engine. The dynamic behaviour of the diesel engine has been assessed using simulation tools. The dynamic analysis will predict the forces and displacements at each of the nodes of the model by forced response analysis. Predicted results and experimentally measured values were found to be in close agreement.
2017-07-10
Technical Paper
2017-28-1947
Suresh Kumar Kandreegula, Kamal Rohilla, Naveen Sukumar, Kunal Kamal
Abstract A propeller shaft is a mechanical component of drive train that connects transmission to drive wheels/axle with the goal to transfer rotation and torque. It is used when the direct connection between transmission and drive axle is not possible due to large distance between their respective assigned design spaces. In commercial vehicles especially in heavy duty (GVW/GCW>15 tons) a single piece propeller shaft is seldom used due to its inherent disadvantages and therefore, most if not all, of the setups consists of multiple pieces of propeller shaft which are directly mounted on to frame cross members with the help of mounting brackets. As such the mounting bracket assembly undergoes various dynamic and static loading conditions and should be able to withstand these loads. This paper will focus on the FEA analysis of propeller shaft mounting assembly system.
2017-07-10
Technical Paper
2017-28-1948
John Samuel Kopppula, Thundil Karuppa Raj Rajagopal, Edison Gundabattini
Abstract The present work is concentrated to study the effect of varying inlet pressures on the dynamics of the suction valve obtained from a hermetic reciprocating compressor. The effect of valve functioning on the efficiency of a compressor is highly acceptable. Rather than the delivery valve, the suction valve has a significant impact on the compressor efficiency. The reed valve in a hermetic compressor is a cantilever type arrangement. The valve operates due to the pressure difference between the suction muffler and the cylinder. The numerical analysis which includes Fluid-structure interaction is used in the present study. The flow and structural domain employed in the present study are modelled with Solidworks 15.0. The fluid structure interaction analysis is a combination of ANSYS Fluent and ANSYS structural. These two are coupled with a system coupling in ANSYS Workbench 16.0. The numerical results obtained from the simulation are validated with the experimental data.
2017-07-10
Technical Paper
2017-28-1953
Tushar Narendra Puri lng, Lalitkumar Ramujagir Soni lng, Sourabh Deshpande
Abstract The infliction of rigorous emission norms across the world has made the automobile industry to focus and dwell upon researches to reduce the emissions from internal combustion engines, namely diesel engines. Variation in fuel injection timing has better influence on reduction of engine exhaust emissions. This papers deals with the variation of fuel injection timing along with fuel injection pressure numerically on a 4 stroke, single cylinder, and direct injection diesel engine running at full load condition using CONVERGE CFD tool. As the piston and bowl geometry considered in this work is symmetric, only 60 degree sector of the piston cylinder assembly is considered for numerical simulation over complete 360 degree model.
2017-07-10
Technical Paper
2017-28-1954
Premkumarr Santhanamm, K. Sreejith, Avinash Anandan
A local and global environmental concern regarding automotive emissions has led to optimize the design and development of Power train systems for IC engines. Blow-by and Engine oil consumption is an important source of hydrocarbon and particulate emissions in modern IC engines. Great efforts have been made by automotive manufacturers to minimize the impact of oil consumption and blow-by on in-cylinder engine emissions. This paper describes a case study of how simulation played a supportive role in improving piston ringpak assembly. The engine taken up for study is a six cylinder, turbocharged, water cooled diesel engine with a peak firing pressure of 140 bar and developing a power output of 227 KW at 1500 rpm. This paper reveals the influence of stepped land, top groove angle, ring face profile, twist features with regard to tweaking of Blow-by & LOC. Relevant design inputs of engine parameters were provided by the customer to firm up the boundary conditions.
Viewing 181 to 210 of 33398