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2015-06-15
Technical Paper
2015-01-2081
Hossein Habibi, Graham Edwards, Liang Cheng, Haitao Zheng, Adam Marks, Vassilios Kappatos, Cem Selcuk, Tat-Hean Gan
Wind turbines mounted on cold climate sites are subject to icing which could significantly influence the performance of turbine blades for harvesting wind energy. To alleviate this problem, a number of techniques have been developed and tested. The currently used methods are surface coating, antifreeze chemicals, electrical resistance heating, hot air circulation, pulse electrothermal de-icing, manual chip-off, etc. Almost all thermal de-ice methods demand a high level of power to operate. Also, the high temperature induced to the blade by the thermal techniques may pose a risk for the integrity of composite blades. A relatively new strategy used for ice protection systems is ultrasonic guided waves (vibrations of very short length wave) on which a few research projects have been recently accomplished. This method is well known for non-destructive testing applications in which the waves typically propagate between 20 kHz and 100 kHz for long-range ultrasonic testing.
2015-04-14
Technical Paper
2015-01-1684
KV Shivaprasad, PR Chitragar, GN Kumar
Fast depletion of fossil fuels and their detrimental effect to the environment is demanding an urgent need of alternative fuels for meeting sustainable energy demand with minimum environmental impact. A lot of research is being carried throughout the world to evaluate the performance, exhaust emission and combustion characteristics of the existing engines using several alternative fuels. Expert studies indicate hydrogen is one of the most promising energy carriers for the future due to its superior combustion qualities and availability. This article experimentally characterizing the combustion and emission parameters of a single cylinder high speed SI engine operating with different concentrations of hydrogen with gasoline fuel. For this purpose, the conventional carbureted high speed SI engine was modified into an electronically controllable engine, wherein ECU was used to control the injection timings and durations of gasoline.
2015-04-14
Journal Article
2015-01-1167
Michele De Gennaro, Elena Paffumi, Giorgio Martini, Urbano Manfredi, Stefano Vianelli, Fernando Ortenzi, Antonino Genovese
The experimental measurement of the energy consumption and efficiency of Battery Electric Vehicles (BEVs) are key topics to determine their usability and performance in real-world conditions. This paper aims to present the results of a test campaign carried out on a BEV, representative of the most common technology available today on the market. The vehicle is a 5-seat car, equipped with an 80 kW synchronous electric motor powered by a 24 kWh Li-Ion battery. The description and discussion of the experimental results is split into 2 parts: Part 1 focuses on laboratory tests, whereas Part 2 focuses on the on-road tests. As far as the laboratory tests are concerned, the vehicle has been tested over three different driving cycles (i.e. NEDC, WLTC and WMTC) at two different ambient temperatures (namely +25 ºC and -7 ºC), with and without the use of the cabin heating, ventilation and air-conditioning system.
2015-04-14
Technical Paper
2015-01-0766
Anshuman Goswami, Sagar Vashist, Ashish Nayyar
This work study reviews the work of various literatures on ‘influence of compression ratio(CR) on the performance of spark ignition engine using different types of fuel blends’ namely E0(gasoline), E25(75% gasoline, 25% ethanol), E10, E20, E22, E50, E75, E100 for different CR. The main parameters considered for comparison were brake specific fuel consumption (BSFC), CR, brake torque (BT),air-fuel ratio(AFR), engine torque and exhaust emissions. The experimental results of various literatures are also included for comparison. The need of advanced engine development techniques and modifications are also studied and emphasis is laid on use of variable compression ratio (VCR) engine (spark ignition). The benefits of using VCR in the coming future are discussed briefly mentioning the challenges faced as well.
2015-04-14
Technical Paper
2015-01-0909
Karthik Nithyanandan, Jiaxiang Zhang, Li Yuqiang, Han Wu, Chia-Fon Lee
Abstract Alcohols, especially n-butanol, have received a lot of attention as potential fuels and have shown to be a possible alternative to pure gasoline. The main issue preventing butanol's use in modern engines is its relatively high cost of production. ABE, the intermediate product in the ABE fermentation process for producing bio-butanol, is being studied as an alternative fuel because it not only preserves the advantages of oxygenated fuels, but also lowers the cost of fuel recovery for individual component during fermentation. With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. In this respect, it is desirable to estimate the performance of different ABE blends to determine the best blend and optimize the production process accordingly.
2015-04-14
Technical Paper
2015-01-1099
Thad Kopp, Larry A. Pritchard
Abstract Recent developments in front wheel drive based all-wheel drive (AWD) systems have focused on the disconnection of the secondary driveline to provide a high efficient 2-Wheel Drive (2WD) mode in order to minimize parasitic losses and increase fuel economy when all-wheel drive is not required. This present study compares a base on-demand all-wheel drive system without disconnect features to one with disconnect features in the rear drive module (RDM) and power transfer unit (PTU) to fully disconnect the secondary drive line. In order to further reduce parasitic losses the RDM also utilized an on-demand lubrication system. In conjunction with the active lubrication system, the oil sump level was reduced to assure all clutch housings and their associated plates were above the oil level at all times in order to minimize shear losses. Positive plate separation was also employed to assure ample clearance for free-running clutch plates.
2015-04-14
Technical Paper
2015-01-0331
Sina Shojaei, Simon Robinson, Chris Chatham, Andrew McGordon, James Marco
Abstract Among the auxiliary systems on electric and hybrid electric vehicles the electric air conditioning (eAC) system causes the largest load on the high voltage battery and can significantly impact the energy efficiency and performance of the vehicle. New methods are being investigated for effective management of air conditioning loads through their integration into vehicle level energy management strategies. For this purpose, a fully integrated vehicle model is developed for a commercially available hybrid vehicle and used to develop energy management algorithms. In this paper, details of the eAC model of this vehicle are discussed, including steady state component validation against rig data. Also results of simulating the cabin pull-down are included.
2015-04-14
Technical Paper
2015-01-0282
Emrah Adamey, Guchan Ozbilgin, Umit Ozguner
Abstract Vehicle tracking problem is of crucial importance in intelligent vehicles research, as it is amongst the basic components of any comprehensive situation awareness technology. In mixed-traffic environments, where vehicles with varying degrees of sensing and communication capabilities coexist, the vehicle-tracking problem becomes particularly more demanding. In this paper, a collaborative vehicle tracking approach is presented, where onboard sensing and inter-vehicular communication resources are utilized in an efficient manner to provide track lists to all participating vehicles in a mixed-traffic environment. The approach is implemented on SimVille, our indoor testbed for urban driving, in accordance with our system development philosophy. The performance of the approach is evaluated using entropy values of vehicle tracks-an information theoretic measure of uncertainty. The experimental results of our scaled-down tests demonstrate the effectiveness of our approach.
2015-04-14
Technical Paper
2015-01-0979
Chih Feng Lee, Per Öberg
Abstract This paper investigates classifications of road type and driving style based on on-board diagnostic data, which is commonly accessible in modern vehicles. The outcomes of these classifications can be utilized in, for example, supporting the advanced driver assistance systems (ADAS) for enhancing safety and drivability, and online adaptation of engine controller for improving performance and fuel consumption. Furthermore, the classifications offer valuable information for fleet operators to consider when making decision on procurement plans, maintenance schedules and assisting fleet drivers in choosing suitable vehicles. To this end, a velocity-based road type classification method is evaluated on measurements collected from real driving conditions and compared to an open-sourced map.
2015-04-14
Technical Paper
2015-01-0611
Aref M. A. Soliman, Mina M.S. Kaldas
Abstract This paper presents experimental and theoretical investigations for ride comfort performance of compressed natural gas fuelled car. A compressed natural gas and gasoline fuel are used to run the engine car and its effect on the vehicle ride comfort is evaluated. The ride comfort performance in terms of experimental Root Mean Square (RMS) values of the vertical acceleration at near driver's feet on the floor, on the front and back seat for the same passenger car fuelled by gasoline and natural gas is evaluated. Furthermore, seven degrees of freedom vehicle mathematical model is developed, and validated through laboratory tests. The validation process is performed by comparing the predicted RMS values of the vertical accelerations with the measured RMS values. Furthermore, the optimum values of vehicle suspension parameters are obtained through the validated vehicle model.
2015-04-14
Technical Paper
2015-01-0752
Zhi Wang, Yunliang Qi, Hui Liu, Yan Long, Jian-Xin Wang
Abstract Occurrence of sporadic super-knock is the main obstacle to the development of advanced gasoline engines. One of the possible inducements of super-knock, agglomerated soot particle induced pre-ignition, was studied for high boosted gasoline direct injection (GDI) engines. The correlation between soot emissions and super-knock frequency was investigated in a four-cylinder gasoline direct injection production engine. The test results indicate that higher in-cylinder soot emission correlate with more pre-ignition and super-knock cycles in a GDI production engine. To study the soot/carbon particles trigger super-knock, a single-cylinder research engine for super-knock study was developed. The carbon particles with different temperatures and sizes were introduced into the combustion chamber to trigger pre-ignition and super-knock.
2015-04-14
Technical Paper
2015-01-0755
Yasuo Moriyoshi, Toshio Yamada, Daisuke Tsunoda, Mingzhao Xie, Tatsuya Kuboyama, Koji Morikawa
Abstract The authors investigated the reasons of how a preignition occurs in a highly boosted gasoline engine. Based on the authors' experimental results, theoretical investigations on the processes of how a particle of oil or solid comes out into the cylinder and how a preignition occurs from the particle. As a result, many factors, such as the in-cylinder temperature, the pressure, the equivalence ratio and the component of additives in the lubricating oil were found to affect the processes. Especially, CaCO3 included in an oil as an additive may be changed to CaO by heating during the expansion and exhaust strokes. Thereafter, CaO will be converted into CaCO3 again by absorbing CO2 during the intake and compression strokes. As this change is an exothermic reaction, the temperature of CaCO3 particle increases over 1000K of the chemical equilibrium temperature determined by the CO2 partial pressure.
2015-04-14
Technical Paper
2015-01-0904
J. Sadhik Basha
Abstract The impact of nano-additives with the diesel and biodiesel fuels is one of the current scopes of research with regards to the fuel modification techniques. Intensive research is underway to utilize the nano-additives judiciously without affecting our ecological environment. In the present work, the effects of nano-additives (Alumina and Carbon Nanotubes) blended biodiesel emulsion fuels on the performance, smoke, gaseous emission and combustion characteristics of a constant speed four stroke single cylinder direct injection diesel engine was investigated. It is recognized that emissions of nanoparticles from diesel engines is of great concern and that if this work demonstrates a performance benefit then further work will be focused on the health impact issues. Esterification and emulsification techniques were adopted to prepare the jatropha biodiesel and jatropha water-biodiesel emulsion fuels respectively. The whole investigation was carried out in five phases.
2015-04-14
Technical Paper
2015-01-0907
Dhanesh G. C. Goberdhan, Robin Hunt
Abstract Studies on cold flow performance have focused on the n-alkane wax precipitating from diesel fuel and their interaction with additives. Little attention has been paid to the solvent system of the fuel. There have been significant changes in the fuel solvent system, due to changes in refining processes and the use of first and second generation biofuels, as well as other components such as GTL. Understanding the extent of the impact of the fuel solvent system change, if and how the change effects wax precipitation, and whether the change influences additive wax interactions, will ultimately enable the optimisation of diesel fuel cold flow performance. This paper first describes a method to characterise diesel fuel solvency. The method is applied to sets of fuels to evaluate the changes in fuel composition over time. A method to replicate the variation in the fuel solvent system is described. The impact of changes in the solvent systems on cold flow properties is considered.
2015-04-14
Technical Paper
2015-01-0973
Aaron Brooker, Jeffrey Gonder, Lijuan Wang, Eric Wood, Sean Lopp, Laurie Ramroth
Abstract The Future Automotive Systems Technology Simulator (FASTSim) is a high-level advanced vehicle powertrain systems analysis tool supported by the U.S. Department of Energy's Vehicle Technologies Office. FASTSim provides a quick and simple approach to compare powertrains and estimate the impact of technology improvements on light- and heavy-duty vehicle efficiency, performance, cost, and battery life. The input data for most light-duty vehicles can be automatically imported. Those inputs can be modified to represent variations of the vehicle or powertrain. The vehicle and its components are then simulated through speed-versus-time drive cycles. At each time step, FASTSim accounts for drag, acceleration, ascent, rolling resistance, each powertrain component's efficiency and power limits, and regenerative braking.
2015-04-14
Technical Paper
2015-01-0324
Zheng David Lou, Shao Wen, Jianhua Qian, Huaiping Xu, Guoming Zhu, Ming Sun
Abstract Camless Variable Valve Actuation (VVA) technologies have been known for improving fuel economy, reducing emissions, and enhancing engine performance. VVA can be divided into electro-magnetic, electro-hydraulic, and electro-pneumatic actuation. This paper presents an electro-hydraulic VVA design (called GD-VVA-2) that offers continuously variable timing and two discrete lifts (low lift S1 and high lift S2). The lift control is achieved through a lift control sleeve, which is hydraulically switched between two mechanically defined positions to provide accurate lifts. The low lift S1 has a wide design range, anywhere between zero and the high lift S2, i.e., 0 < S1 < S2. If S1 ≥ 0.5*S2, engine valves may operate at the low lift during most of a typical drive cycle. Operation at the low lift reduces energy consumption significantly. The GD-VVA-2 design offers compact package size and reasonable energy consumption.
2015-04-14
Technical Paper
2015-01-0996
Harsha Nanjundaswamy, Vinay Nagaraju, Yue Wu, Erik Koehler, Alexander Sappok, Paul Ragaller, Leslie Bromberg
Abstract Although designed for the purpose of reducing engine-out Particulate Matter (PM) emissions to meet or exceed mandated emissions regulations, the particulate filter also incurs a fuel economy penalty. This fuel penalty is due to the increased exhaust flow restriction attributed to the PM accumulated in the filter, in addition to fuel consumed for active regeneration. Unlike the soot which may be oxidized through the regeneration process, incombustible material or ash continues to build-up in the filter following each regeneration event. Currently pressure- and model-based controls are used to provide an indirect estimate of the loading state of the particulate filter, in order to manage the filter operation and determine when to regenerate the filter. The challenges associated with pressure- and model-based particulate filter control over real-world operating conditions are well-known.
2015-04-14
Technical Paper
2015-01-1221
Jamie Knapp, Adam Chapman, Sagar Mody, Thomas Steffen
Hybrid electric vehicles offer significant fuel economy benefits, because battery and fuel can be used as complementing energy sources. This paper presents the use of dynamic programming to find the optimal blend of power sources, leading to the lowest fuel consumption and the lowest level of harmful emissions. It is found that the optimal engine behavior differs substantially to an on-line adaptive control system previously designed for the Lotus Evora 414E. When analyzing the trade-off between emission and fuel consumption, CO and HC emissions show a traditional Pareto curve, whereas NOx emissions show a near linear relationship with a high penalty. These global optimization results are not directly applicable for online control, because they require knowledge of the whole drive cycle in advance, but they can guide the design of a more efficient hybrid control system.
2015-04-14
Technical Paper
2015-01-0785
Dockoon Yoo, Jihun Song, Yeongchu Kim, Wook Jung, Duksang Kim
Abstract As presented in the previous study [1], a 2.4L ULPC(Ultra Low PM Combustion) diesel engine was achieved through optimal matching with piston bowl geometry and nozzle spray angle that significantly reduce the amount of engine out soot generated in the combustion. This engine complies with US Tier 4 Final regulation without DPF (only DOC) which was developed for off-road applications such as skid-loader, forklift and construction equipment. Improvement in fuel consumption of diesel engine for off-road applications and construction equipment which are operating continuously for a long time at high load conditions will be very important for reducing the operating costs. This paper explains a detailed review of improvement BSFC of 2.4L ULPC diesel engine by optimizing the combustion system with swirl ratio, nozzle flow rate and piston bowl geometry while maintaining non-DPF solution.
2015-04-14
Technical Paper
2015-01-0772
Ashish J. Chaudhari, Vinayak Kulkarni, Niranjan Sahoo
Abstract In this study, the effect of using higher research octane rating fuel Liquefied Petroleum Gas (LPG) in respect of gasoline in the spark ignition engine on the performance and exhaust emission was experimentally studied. For this purpose, the tilting block technique of varying the compression ratio from 8 to 10 of the engine has been implemented and attention has been paid towards the variation of performance and combustion parameters with LPG fuel. Most undesirable emissions are exhausted by the spark ignition (SI) engines in which the primary pollutants from the engine (such as NOx) which when mixed in the atmosphere react with ozone and create the secondary pollutant that are more harmful to human health. Looking at this fact, while optimizing the compression ratio, the emission reduction technique like intake charge dilution with exhaust gas from the engine has been studied.
2015-04-14
Technical Paper
2015-01-0770
Mehrdad Afshari, Jafar Hashemi Daryan, Seyed Ali Jazayeri, Reza Ebrahimi, Farshad Salimi Naneh Karan
Abstract Currently, the interest in using alternative clean types of fuels has been extensively increased all over the world because of the global approach in reducing engine emissions and creating new sources of fuel for internal combustion engines. The hydrogen-methane blend is one of the alternative fuels which includes the benefits of both of the fuels compared to the traditional petrol/gasoline fuel. This paper addresses a two-zone quasi-dimensional model to investigate the performance of an SI engine which uses a mixture of methane and hydrogen. In this model, gases inside the cylinder are divided into two regions: burned and the unburned. The chemical reactions are supposed to be in equilibrium in each zone, but the extended Zedlovich mechanism is utilized to determine the amount of the NOx available in the exhaust gas. Also, CO concentration is determined by two steps kinematic reactions.
2015-04-14
Technical Paper
2015-01-0768
Louis Sileghem, Andrew Ickes, Thomas Wallner, Sebastian Verhelst
Abstract Stricter CO2 and emissions regulations are pushing spark ignition engines more and more towards downsizing, enabled through direct injection and turbocharging. The advantages which come with direct injection, such as increased charge density and an elevated knock resistance, are even more pronounced when using low carbon number alcohols instead of gasoline. This is mainly due to the higher heat of vaporization and the lower air-to-fuel ratio of light alcohols such as methanol, ethanol and butanol. These alcohols are also attractive alternatives to gasoline because they can be produced from renewable resources. Because they are liquid, they can be easily stored in a vehicle. In this respect, the performance and engine-out emissions (NOx, CO, HC and PM) of methanol, ethanol and butanol were examined on a 4 cylinder 2.4 DI production engine and are compared with those on neat gasoline.
2015-04-14
Technical Paper
2015-01-0776
Gerben Doornbos, Stina Hemdal, Daniel Dahl
Abstract This study investigated how the amount of dilution applied can be extended while maintaining normal engine operation in a GDI engine. Adding exhaust gases or air to a stoichiometric air/fuel mixture yields several advantages regarding fuel consumption and engine out emissions. The aim of this paper is to reduce fuel consumption by means of diluted combustion, an advanced ignition system and adjusted valve timing. Tests were performed on a Volvo four-cylinder engine equipped with a dual coil ignition system. This system made it possible to extend the ignition duration and current. Furthermore, a sweep was performed in valve timing and type of dilution, i.e., air or exhaust gases. While maintaining a CoV in IMEP < 5%, the DCI system was able to extend the maximum lambda value by 0.1 - 0.15. Minimizing valve overlap increased lambda by an additional 0.1.
2015-04-14
Technical Paper
2015-01-0775
Ahmad Omari, Michael Shapiro, Leonid Tartakovsky
Abstract Utilizing heat of exhaust gases for on-board alcohol reforming process (thermo-chemical recuperation - TCR) is a promising way of increasing the internal combustion engine (ICE) efficiency and emissions mitigation. Knowledge of the laminar burning velocity of alcohol reforming products is necessary for simulating performance of internal combustion engines with TCR and for in-depth studies of the combustion process. Laminar burning velocities of H2, CO, CO2 and CH4 mixtures that simulate methanol and ethanol steam reforming products for various water-alcohol ratios are investigated in this work. The influence of flame cellularity on burning velocity is studied as well. The burning velocity is measured experimentally using a spherical closed combustion vessel. Measurements are taken by a pressure measurement method during the pressure-rise period and prior to it by a high-speed Schlieren photography.
2015-04-14
Technical Paper
2015-01-0798
Philipp Seidenspinner, Martin Härtl, Thomas Wilharm, Georg Wachtmeister
Abstract A new constant volume combustion chamber (CVCC) apparatus is presented that calculates the cetane number (CN) of fuels from their ignition delay by means of a primary reference fuel calibration. It offers the benefits of low fuel consumption, suitability for non-lubricating substances, accurate and fast measurements and a calibration by primary reference fuels (PRF). The injection system is derived from a modern common-rail passenger car engine. The apparatus is capable of fuel injection pressures up to 1200 bar and requires only 40 ml of the test fuel. The constant volume combustion chamber can be heated up to 1000 K and pressurized up to 50 bar. Sample selection is fully automated for independent operation and low levels of operator involvement. Capillary tubes employed in the sampling system can be heated to allow the measurement of highly viscous fuels.
2015-04-14
Technical Paper
2015-01-0821
Alvaro Pinheiro, David Vuilleumier, Darko Kozarac, Samveg Saxena
Abstract This paper follows a cycle-simulation method for creating an engine performance map for an ethanol fueled boosted HCCI engine using a 1-dimensional engine model. Based on experimentally determined limits, the study defined operating conditions for the engine and performed a limited parameter sweep to determine the best efficiency case for each condition. The map is created using a 6-Zone HCCI combustion model coupled with a detailed chemical kinetic reaction mechanism for ethanol, and validated against engine data collected from a 1.9L 4-Cylinder VW TDI engine modified to operate in HCCI mode. The engine was mapped between engine speeds of 900 and 3000 rpm, 1 and 3 bar intake pressure, and 0.2 and 0.4 equivalence ratio, resulting in loads between idle and 14.0 bar BMEP. Analysis of a number of trends for this specific engine map are presented, such as efficiency trends, effects of combustion phasing, intake temperature, engine load, engine speed, and operating strategy.
2015-04-14
Technical Paper
2015-01-0807
Khanh Cung, Jaclyn Johnson, Seong-Young Lee
Abstract Dimethyl ether (DME) appears to be an attractive alternative to common fossil fuels in compression ignition engines due to its smokeless combustion and fast mixture formation. However, in order to fully understand the complex combustion process of DME, there is still a remaining need to develop a comprehensive chemical kinetic mechanism that includes both soot and NOx chemistry. In this study, a detailed DME mechanism with 305 species is developed from the basic DME mechanism of Curran et al. (2000) with addition of soot and NOx chemistry from Howard's mechanism et al. (1999), and GRI 3.0 mechanism, respectively. Soot chemistry in Howard mechanism consisting hydrogen abstraction acetylene addition (HACA) and growth of small polycyclic aromatic hydrocarbons (PAH), assesses over a wide range of temperature and is able to predict good to fair the formation of PAH up to coronene.
2015-04-14
Technical Paper
2015-01-0287
Javier Adolfo Alcazar, David Weber
Abstract This paper proposes and verifies a potential application of Vehicle-to-Vehicle (V2V) technology: An on-line method to merge onto highways using V2V communications. Vehicles equipped with Global Positioning System (GPS) and Dedicated Short Range Communication (DSRC) are capable of broadcasting vehicle's GPS data to neighboring vehicles. Vehicles traveling along the highway share traffic information via DSRC. Using position and speed a velocity profile for merging is proposed. Such information allows vehicles to adapt their speed and position specifically at merging intersections enabling smooth traffic flow. Vehicles equipped with GPS and DSRC could enable smoother traffic flow and fewer collisions.
2015-04-14
Technical Paper
2015-01-0356
Aniket Patil, Manoj Radle, Biswadip Shome, Sankar Ramachandran
Abstract Passenger comfort and safety are major drivers in a typical automotive design and optimization cycle. Addressing thermal comfort requirements and the thermal management of the passenger cabin within a car, which involves accurate prediction of the temperature of the cabin interior space and the various aggregates that are present in a cabin, has become an area of active research. Traditionally, these have been done using experiments or detailed three-dimensional Computational Fluid Dynamics (CFD) analysis, which are both expensive and time-consuming. To alleviate this, recent approaches have been to use one-dimensional system-level simulation techniques with a goal to shorten the design cycle time and reduce costs. This paper describes the use of Modelica language to develop a one-dimensional mathematical model using Modelica language for automotive cabin thermal assessment when the car is subjected to solar heat loading.
2015-04-14
Technical Paper
2015-01-0336
Amey Karnik, Daniel Pachner, Adrian M. Fuxman, David Germann, Mrdjan Jankovic, Christopher House
Abstract Numerous studies describe the fuel consumption benefits of changing the powertrain temperature based on vehicle operating conditions. Actuators such as electric water pumps and active thermostats now provide more flexibility to change powertrain operating temperature than traditional mechanical-only systems did. Various control strategies have been proposed for powertrain temperature set-point regulation. A characteristic of powertrain thermal management systems is that the operating conditions (speed, load etc) change continuously to meet the driver demand and in most cases, the optimal conditions lie on the edge of the constraint envelope. Control strategies for set-point regulation which rely purely on feedback for disturbance rejection, without knowledge of future disturbances, might not provide the full fuel consumption benefits due to the slow thermal inertia of the system.
Viewing 1 to 30 of 16768