Criteria

Text:
Display:

Results

Viewing 1 to 30 of 3886
2016-10-25
Event
Separate sub-sessions cover zero-dimensional, one-dimensional, and quasi-dimensional models for simulation of SI and CI engines with respect to: engine breathing, boosting, and acoustics; SI combustion and emissions; CI combustion and emissions; fundamentals of engine thermodynamics; numerical modeling of gas dynamics; thermal management; mechanical and lubrication systems; system level models for controls; system level models for vehicle fuel economy and emissions predictions.
2016-10-17
Technical Paper
2016-01-2178
Daniela Siano, Gerardo Valentino, Fabio Bozza, Arturo Iacobacci, Luca Marchitto
In this paper, a downsized twin-cylinder turbocharged spark-ignition engine is experimentally investigated at test-bench in order to verify the potential to estimate the peak pressure value and the related crank angle position based on vibrational data acquired by an accelerometer sensor. Purpose of the activity is to provide the ECU of additional information to establish a closed-loop control of the spark timing, on a cycle-by-cycle and cylinder-by-cylinder basis. In this way, an optimal combustion phasing can be more properly accomplished in each engine operating condition. Vibrational data are also employed to have information on cycle-by-cycle variations (CCVs) of the pressure peak. More sophisticated techniques for the control of the cycle dispersion are also foreseen. To this aim, engine behavior is firstly characterized in terms of average thermodynamic and performance parameters and CCVs at high-load operation.
2016-10-17
Technical Paper
2016-01-2228
Mithilesh Kumar Sahu, Tushar Choudhary, Sanjay Y
Global energy scenario requires thermal systems with high thermal efficiency and low capital and operating cost. The paper deals with the thermoeconomic analysis of the gas turbine cycles with possible application as marine gas turbines. A thermoeconomic analysis is a combined study of thermodynamic and economic parameters of proposed energy conversion cycle. In present paper gas turbine of suitable configuration has been analysed. Different configurations of gas turbine have been analysed using thermo-economic methodology keeping the gas turbine output fixed. The approach used for solution of this is thermoeconomic optimization by considering appropriate objective function in a form of decision variables. This objective function combines the expenditure of financial resources (economics) and thermodynamic equations.
2016-10-17
Technical Paper
2016-01-2227
Nik Muhammad Hafiz, Mohd Radzi Abu Mansor, Wan Mohd Faizal Wan Mahmood, Masahiro Shioji
Hydrogen as a fuel in internal combustion engines has been studied extensively by researchers nowadays. Among the advantages of hydrogen are it is sustainable renewable energy, and the emission from combustions is environmentally friendly compared with other conventional fuel, which complies with a stringent policy from international energy agency. Moreover, emission from hydrogen fuel will meet the new regulation set by Malaysia National Automotive Policy (NAP). In order to enhance power output and volumetric efficiency, at the same time encounter the pre-ignition and knock problems, the hydrogen fuel compression ignition internal combustion engine in the noble gas atmosphere (argon) is selected as one of a solution by some researchers. However, the obtained data for this kind of research is still at the initial stage.
2016-10-17
Technical Paper
2016-01-2230
Vincenzo De Bellis, Fabio Bozza, Daniela Siano, Gerardo Valentino
In this paper, the results of an extensive experimental analysis regarding a twin-cylinder spark-ignition turbocharged engine are employed to build up an advanced 1D model, which includes the effects of cycle-by-cycle variations (CCVs) on the combustion process. Objective of the activity is to numerically estimate the CCV impact primarily on fuel consumption and knock behavior. To this aim, the engine is experimentally characterized in terms of average performance parameters and CCVs at high and low load operation. In particular, both a spark advance and an air-to-fuel ratio () sweep are actuated. Acquired pressure signals are processed to estimate the rate of heat release and the main combustion events. Moreover, the Coefficient of Variation of IMEP (CoVIMEP) and of in-cylinder peak pressure (CoVpmax) are evaluated to quantify the cyclic dispersion and identify its dependency on peak pressure position.
2016-10-17
Technical Paper
2016-01-2233
Matthew C. Robinson, Nigel Clark
The free piston engine combined with a linear electric alternator has the potential to be a highly efficient converter from fossil fuel energy to electrical power. With only a single moving part (the translating rod) mechanical friction is reduced compared to conventional crankshaft technology. Instead of crankshaft linkages, the motion of the translator is driven primarily by the force balance between the engine cylinder, alternator, damping losses, and springs. Focusing primarily on mechanical springs, this paper explores the use of springs to increase engine speed and reduce cyclic variance. A numeric model has been constructed in MATLAB®/Simulink to represent the various subsystems, including the engine, alternator, and springs. Within the simulation is a controller that tries to force the engine to operate at a fixed compression ratio by affecting the alternator load.
2016-10-17
Technical Paper
2016-01-2231
Aras Mirfendreski, Andreas Schmid, Michael Grill, Michael Bargende
Longitudinal models are used to evaluate different vehicle-engine concepts with respect to driving behavior and emissions. The engine is generally map-based. An explicit calculation of both fluid dynamics inside the engine air path and cylinder combustion is not considered due to long computing times. Particularly for dynamic certification cycles (WLTC, US06 etc.), dynamic engine effects severely influence the quality of results. Hence, an evaluation of transient engine behavior with map-based engine models is restricted to a certain extent. The coupling of detailed 1D-engine models is an alternative, which rapidly increases the model computation time to approximately 300 times higher than that of real time In many technical areas, the Fourier Transformation (FT) method is applied, which makes it possible to represent superimposed oscillations by their sinusoidal harmonic oscillations of different orders.
2016-10-17
Technical Paper
2016-01-2234
Ahmed F. Khan, Alexey Burluka, Jens Neumeister, Dave OudeNijewem, Paul Freeland
A holistic modelling approach has been employed to predict combustion, cyclic variability and knock propensity of a turbocharged downsized SI engine fuelled with gasoline. A quasi-dimensional, thermodynamic combustion modelling approach has been coupled with chemical kinetics modelling of autoignition using reduced mechanisms for realistic gasoline surrogates. The quasi-dimensional approach allows a fast and appreciably accurate prediction of the effects of operating conditions on the burn-rate and makes it possible to evaluate engine performance. It has also provided an insight into the nature of the turbulent flame as the boost pressure and speed is varied. In order to assess the sensitivity of the end-gas chemical kinetics to cyclic variability, the in-cylinder turbulence and charge composition were perturbed according to a Gaussian distribution.
2016-10-17
Technical Paper
2016-01-2232
Yves Compera, Bernhard Penkert, Georg Wachtmeister
This paper presents a phenomenological and semi-empirical simulation model to predict the injection rate of a diesel solenoid valve injector based on few injection-quantity measurements and indications (EMI). The approached injection rate will be used as the input data for a subsequent model which simulates the rate of heat release (ROHR). The injection rate model encompasses algebraic relations and differential equations deviated of the equations of motion and conservation, which describe in modular sub models the characteristic processes in the injector. The process and its assumptions are explained step by step for each sub model. Additionally the injection rate predictions are presented and compared with experimental results for a selected reference solenoid valve injector.
2016-09-27
Technical Paper
2016-01-8024
Saurabh gupta, Gopichand vunnava
In search of higher productivity, farmers are taking more than two crops in a year. In this farming pattern they don’t have much time for field preparation due to which rear mounted plough have become longer and heavier, necessitating the use of additional front-end weights and assister rams on the hydraulic lift. As plough length increases, the evenness of working depth over the full length of the implement deteriorates. To complete the farm work in one or two passes by utilizing maximum tractor power in order to save the fuel as well as time. The usage of front hitch and front PTO system on tractor forms a gateway for farmers to control the traffic on farm fields which is responsible for the soil compaction and emissions of green house gases into the atmosphere by reducing the number of passes in agricultural field operations.
2016-09-27
Technical Paper
2016-01-8071
Igor Gritsuk, Vladimir Volkov, Yurii Gutarevych, Vasyl Mateichyk, Valeriy Verbovskiy
The article discusses the use of the combined heating system with phase-transitional thermal accumulator. The peculiarity of the presented system is that it uses thermal energy of exhaust gas, coolant and motor oil, and emissions of internal combustion engine during its operation to accumulate the thermal energy. The results of experimental studies of the combined heating system are shown. The use of the combined heating system within phase-transitional thermal accumulators is compared with the use of standard systems for vehicle engine ZMZ-66-06 (8FS 9.2 / 8) of truck GAZ-66-11. In case of using a single thermal accumulator it allows to reduce the heating time up to 22.9-79.6% for a coolant and up to 25-80.8% for motor oil. A system and methods for pre-start and after-start heating of the vehicle engine in the investigated system are developed. The structure of a mathematical model to study the engine heating system in its various options is described.
2016-09-27
Technical Paper
2016-01-8079
Zhiwei Zhang
Abstract: Hydraulic retarder is an important auxiliary braking device. Because of its large braking torque in high speed, smooth braking, low noise, long service life and small size, it is widely used on modern vehicles. Transmission fluid of traditional hydraulic retarder is cooled by engine cooling system, which is a waste of vehicle energy to discharge the exhausted heat directly. On account of the working characteristics of hydraulic retarder, this study designs a set of waste heat recovery system based on Organic Rankine Cycle(ORC). Under the premise of ensuring stable performance of hydraulic retarder, waste heat energy in transmission fluid is recycled to supplement energy requirements for cooling system. First of all, the principle model of 100:1 is established for thermal power of D300 retarder. Then through theoretical calculations, components' structural parameters of ORC are determined.
2016-09-20
Technical Paper
2016-01-2030
Jon Zumberge, Michael Boyd, Raul Ordonez
Cost and performance requirements are driving military and commercial systems to highly integrated, optimized systems which require more sophisticated, highly complex controls. To realize benefits of those complex controls and make confident decisions, the validation of both plant and control models becomes critical. To quickly develop controls for these systems, it is beneficial to develop plant models and determine the uncertainty of those models to predict performance and stability of the control algorithms. A process of model and control algorithm validation for a dc-dc boost converter circuit based on acceptance sampling is presented here. The validation process described in this paper is based on MIL-STD 3022 with emphasis on requirements settings and the testing process. The key contribution of this paper is the process for model and control algorithm validation specifically a method for decomposing the problem into model and control algorithm validation stages.
2016-09-20
Technical Paper
2016-01-2033
Rudolf Neydorf, Ivan Chernogorov, Victor Polyakh, Orkhan Yarakhmedov, Julia Goncharova, Anna Neydorf
Experimental and computer modelling of statics and dynamics of vehicles may cause difficulties related with significant non-linearity of dependencies included in a model. This is due to the mechanical effects of friction, backlash etc., aerodynamic effects and other physical phenomena. Mathematical modeling of such objects is most frequently connected with mathematical processing of experimental data. Obtained pointlike dependencies of output variables on input ones are strongly nonlinear, piecewise, sometimes discontinuous. Approximation of these dependencies using polynomial resolution or spline-functions is problematic and may cause low accuracy. A radically new solution of this problem was suggested in the article [Neydorf, R., "Bivariate “Cut-Glue” Approximation of Strongly Nonlinear Mathematical Models Based on Experimental Data," SAE Int. J. Aerosp. 8(1):2015, doi:10.4271/2015-01-2394].
2016-09-20
Technical Paper
2016-01-2035
Rudolf Neydorf, Anna Neydorf
The main difficulties of the mathematical models vehicles creation are defined by strongly nonlinearity of dependences which connect various variable their states and conditions of the movement environment. Most it belongs to aircrafts as aerodynamic interactions are characterized by essential nonlinearity up to discontinuity of variables and their derivatives. Creation process of these models is complicated by high-dimensionality, characteristic for the mechanical movement laws. Approximating creation of mathematical models (MM) of such dependences by modern mathematical methods (polynomial decomposition, a spline functions, etc.) is laborious and insufficiently exact. The author investigated possibility of a method creation of high-precision analytical approximation of nonlinear dependences by mathematical models. The received results are stated in two fundamental articles: [Neydorf R.A.
2016-09-20
Technical Paper
2016-01-2046
Neno Novakovic
A Landing Gear Control and Actuation System (LGCAS) is one of the most complex aircraft systems. Due to the large landing gear masses and high performance requirements, aircraft hydraulic power with multiple hydraulic actuators and valves is used to provide system dynamic. LGCAS also requires an electrical source of energy for the electro-mechanical components, sensors and electronic control unit. For many years, correct fault isolation in a complex kinematic system, such as an aircraft landing gear actuation system, has been a great challenge with limited success. The fault isolation design challenge rests on the fact that landing gear control and actuation system has many so called “passive” components, whose basic function cannot be continuously monitored without additional sensors, transducers and designated health monitoring equipment.
2016-09-18
Technical Paper
2016-01-1935
Binyu Mei, Xuexun Guo, Gangfeng Tan
With the continuous increasing requirements of commercial vehicle weight and speed on highway transportation, conventional friction brake is difficult to meet the braking performance. To ensure the driving safety of the vehicle in the hilly region, eddy current retarder has been widely used due to its fast response, lower prices and convenient installation. Electric eddy current retarder breaks the vehicle through the electromagnetic force generated by the current, and converted vehicle mechanical energy into heat through magnetic field. Air cooling structure is often used in the traditional eddy current retarder and cooling performance is limited, which causes low breaking torque, thermal recession, low reliability and so on. A water jacket has been equipped outside the eddy current region in this study, and the electric eddy current retarder is cooled through the water circulating in the circuit, which prolongs its working time.
2016-06-17
Journal Article
2016-01-9141
Vinod Saini, Sanchit Singh, Shivaram NV, Himanshu Jain
Abstract In this paper, an optimization method is proposed to improve the efficiency of a transmission equipped electric vehicle (EV) by optimizing gear shift strategy. The idea behind using a transmission for EV is to downsize the motor size and decrease overall energy consumption. The efficiency of an electric motor varies with its operating region (speed/torque) and this plays a crucial role in deciding overall energy consumption of EVs. A lot of work has been done to optimize gear shift strategy of internal combustion engines (ICE) based automatic transmission (AT), and automatic-manual transmissions (AMT), but for EVs this is still a new area. In case of EVs, we have an advantage of regeneration which makes it different from the ICE based vehicles. In order to maximize the efficiency, a heuristic search based algorithm - Genetic Algorithm (GA) is used.
2016-05-01
Journal Article
2015-01-9148
Saeed Asgari, Shailendra Kaushik
Abstract A linear parameter varying (LPV) reduced order model (ROM) is used to approximate the volume-averaged temperature of battery cells in one of the modules of the battery pack with varying mass flow rate of cooling fluid using uniform heat source as inputs. The ROM runs orders of magnitude faster than the original CFD model. To reduce the time it takes to generate training data, used in building LPV ROM, a divide-and-conquer approach is introduced. This is done by dividing the battery module into a series of mid-cell and end-cell units. A mid-cell unit is composed of a cooling channel sandwiched in between two half -cells. A half-cell has half as much heat capacity as a full-cell. An end-cell unit is composed of a cooling channel sandwiched in between full-cell and a half-cell. A mass flow rate distribution look-up-table is generated from a set of steady-state simulations obtained by running the full CFD model at different inlet manifold mass flow rate samples.
2016-04-11
Journal Article
2016-01-9016
Mohammad Gerami Tehrani, Juuso Kelkka, Jussi Sopanen, Aki Mikkola, Kimmo Kerkkänen
Abstract The feasibility of improving the energy efficiency of Electric Vehicles (EV) by manipulating operation points by means of a variable transmission is investigated with an efficient mathematical model of power losses in all driveline components. Introduced model can be solved in real-time making it possible to embed it to a control scheme of EV. Empirical test results are employed to derive the efficiency of the power electronics and electric motor at operation points while the mechanical power losses are predicted by a comprehensive and generic formulation for efficiency analysis. The simulation model used comprises electrical component efficiency, drivetrain inertias, gearbox efficiency, regenerative braking, and gear ratio selection. Three different transmission types are studied in this work; a single reduction gear, a five-step gearbox and an Infinitely Variable Transmission.
2016-04-05
Technical Paper
2016-01-0900
Sijia Zheng, Wen Fan
Abstract About 40% of the fuel energy in an internal combustion engine is lost as exhaust heat. Thermoelectric generators (TEGs) can recover the heat energy in the exhaust gas, improving the fuel efficiency of the vehicle and reducing emissions. In this study, a method of setting up TEG model using real testing data is proposed; model of a TEG-based vehicle power system is built; and the potential of the TEGs to improve the fuel efficiency of conventional vehicles and hybrid electric vehicles (HEVs) is examined by integrating the TEG into the vehicle power bus as a second generator. Firstly, output power model of one thermoelectric module is constructed in MATLAB/Simulink according to testing data, which is convenient and convincing. Then the model of TEG system is built using Matlab/Simulink software, taking the temperature distribution of the heat exchanger into consideration.
2016-04-05
Technical Paper
2016-01-0960
Arifumi Matsumoto, Kenji Furui, Makoto Ogiso, Toru Kidokoro
Abstract Urea selective catalytic reduction (SCR) systems are a promising technology for helping to lower NOx emissions from diesel engines. These systems also require on-board diagnostic (OBD) systems to detect malfunctioning catalysts. Conventional OBD methodology for a SCR catalyst involves the measurement of NOx concentration downstream of the catalyst. However, considering future OBD regulations, erroneous diagnostics may occur due to variations in the actual environment. Therefore, to enhance OBD accuracy, a new methodology was examined that utilizes NH3 slip as a new diagnostic parameter in addition to NOx. NH3 slip increases as the NOx reduction performance degrades, because both phenomena are based on deterioration in the capability of the SCR catalyst to adsorb NH3. Furthermore, NH3 can be measured by existing NOx sensors because NH3 is oxidized to NO internally. To make use of NH3 slip, an estimation model was developed.
2016-04-05
Technical Paper
2016-01-1037
Lars Eriksson, Vaheed Nezhadali, Conny Andersson
Modelbased systems engineering is becoming an important tool when meeting the challenges of developing the complex future vehicles that fulfill the customers and legislators ever increasing demands for reduced pollutants and fuel consumption. To be able to work systematically and efficiently it is desirable to have a library of components that can be adjusted and adapted to each new situation. Turbocharged engines are complex and the compressor model serves as an in-depth example of how a library can be designed, incorporating the basic physics and allowing fine tuning as more information becomes available. A major part of the paper is the summary and compilation of a set of rules of thumb for compressor map extrapolation. The considerations discussed are extrapolation to surge, extrapolation to restriction region, and extrapolation out to choking.
2016-04-05
Technical Paper
2016-01-1384
Mengshi Deng, Jian Lan
Abstract Glass lifter is a key part of automobile door system. Guide rail is the carrier of glass lifter, and it bears various load cases when glass lifer works. Mass, stiffness and natural frequencies are the factors that influence the performance of glass lifter. In order to design a lighter and reasonable glass lifter, topology optimization methods are studied in this paper. In a rope-wheel glass lifter, design domain is determined by the mechanical structure and working conditions. Firstly, the single target continuum structure topology optimization mathematic models of guide rail are built in this paper, and analysis of multi-stiffness topology optimization are carried out accordingly in which volume fraction is set as 0.4, 0.5 and 0.6. These models are based on SIMP (Solid Isotropic Material with Penalization) theory.
2016-04-05
Technical Paper
2016-01-1309
Yingping Lv, Yongchang Du, Yujian Wang
Abstract In this paper, analysis methods for brake squeal including substructure modal composition analysis and substructure modal parameters sensitivity analysis are presented. These methods are based on a new closed-loop coupling disc brake model, where the coupled nodal pairs in each coupling interface are connected tightly. This assumption is different from other existing models in literatures, where the interface nodes are coupled through assumed springs. Based on this new model, two analysis methods are derived: Substructure modal composition analysis indicates the contribution of modes of each substructure to the noise mode; Substructure modal parameters sensitivity analysis indicates the sensitivity of the real part of system’s eigenvalue to component’s modal frequency and shape. Finally, the presented analysis methods are applied to analyse a high frequency squeal problem of a squealing disc brake.
2016-04-05
Technical Paper
2016-01-1622
Miroslav Mokry
Abstract Lagally’s theorem is used to evaluate the increments to aerodynamic forces on automotive models, tested in solid-wall wind tunnels. The strengths of the model-representing singularities, pre-requisite for the application of the theory, are obtained from experimental wall pressure data, using an influence matrix method. The technique is demonstrated on the drag force acting on full-size and half-size truck models, measured in the same test section.
2016-04-05
Technical Paper
2016-01-1557
Francesco Castellani, Nicola Bartolini, Lorenzo Scappaticci, Davide Astolfi, Matteo Becchetti
Abstract Shock absorber is one of the most relevant sub-systems of the suspension system for a wide range of vehicles. Although a high level of development and tuning has been reached, in order to ensure high safety standards in almost every situation, some dynamic phenomena affecting vehicle handling or NHV (Noise Vibration Harshness) can appear. The aim of present work is to improve a mathematical model using experimental data from a prototype of monotube shock absorber developed for research purposes. The model takes into account all the main features affecting the global performance of the device, such as non-linear behaviour and the presence of hysteresis loops. Actually, the most important parameters are analyzed, such as flow and orifice coefficients of the valves, coefficients of mechanical compliance of the chambers and oil compressibility, dry and viscous friction coefficients.
2016-04-05
Technical Paper
2016-01-1546
Dongpil Lee, Bongchoon Jang, Kyongsu Yi, Sehyun Chang, Byungrim Lee
Abstract This paper describes a reference steering feel tracking algorithm for Electric-Power-Steering (EPS) system. Development of the EPS system with intended steering feel has been time-consuming procedure, because the feedforward map-based method has been applied to the conventional EPS system. However, in this study, a three-dimensional reference steering feel surface, which is determined from current vehicle states, is proposed. In order to track the proposed reference steering feel surface, sliding mode approach is applied to second-order steering dynamics model considering a coulomb friction model. An adaptive technique is utilized for robustness against uncertainties. In order to validate the proposed EPS control algorithm, hardware-in-the-loop simulation (HILS) has been conducted with respect to a typical steering test. It is shown that the reference steering feel is realized well by the proposed EPS control algorithm.
2016-04-05
Technical Paper
2016-01-1544
Dexin Wang, Frank Esser
Abstract Evaluation of electric steering (EPAS) system performance using vehicle specific load conditions is important for steering system design validation and vehicle steering performance tuning. Using real-time vehicle dynamics mathematical models is one approach for generating steering loads in steering hardware-in-the-loop (HIL) testing. However achieving a good correlation of simplified mathematical models with real vehicle dynamics is a challenge. Using rack force models from measured steering tie rod forces or from simulations using a high-fidelity vehicle dynamics model is an effective data-driven modelling method for testing EPAS systems under vehicle specific load conditions. Rack force models are identified from physical measurements or validated vehicle simulations of selected steering test maneuvers. The rack force models have been applied in steering system performance evaluation, benchmarking, and steering model validation.
Viewing 1 to 30 of 3886

Filter

  • Range:
    to:
  • Year: