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Viewing 151 to 180 of 22369
Technical Paper
2014-04-01
Xin Wang, Yunshan Ge
Abstract Compressed natural gas (CNG) is widely used as an alternative option in spark ignition engines because of its better fuel economy and in part cleaner emissions. To cope with the haze weather in Beijing, about 2000 gasoline/CNG dual-fuel taxis are servicing on-road. According to the government's plan, the volume of alternative fuel and pure electric vehicle will be further increased in the future. Thus, it is necessary to conduct an evaluation on the effectiveness of alternative fuel on curbing vehicular emissions. This research examined the regulated emissions and particulate matter of gasoline/CNG dual-fuel taxi over New European Driving Cycle (NEDC). Emission tests in gasoline- and CNG-fuelled, cold- and warm-start modes were done for all five taxies. Test vehicles, Hyundai Elantra, are powered by 1.6L spark-ignited engines incorporated with 5-gear manual gearboxes. The taxis were registered in May and June, 2013, and their millage was within 3500 and 10000 km on odometer when the emission tests were performed.
Technical Paper
2014-04-01
Navin Kumar, Abyarth Behera, Dulari Hansdah, Murugan Sivalingam
Abstract Madhuca indica flower is a forest residue used for preparation of food and liquor in tribal areas of India. In this present investigation, bioethanol produced from madhuca indica flower by the fermentation process is proposed as an alternative fuel for diesel engines. As the cetane number of bioethanol is low, an ignition improver is required for better operation. In this study, Diethyl ether (DEE), an ignition improver is fumigated at two different flow rates viz 120 g/h and 240 g/h in the intake manifold along with the air in a single cylinder, four stroke, DI diesel engine developing a power of 4.4 kW at a rated speed of 1500 rpm. The brake thermal efficiency (BTE) is found to be higher by about 10.47 and 2.46% with 120 g/h and 240 g/h flow rate of the DEE respectively, compared to that of diesel at full load. The brake specific nitric oxide (BSNO) emission is found to be lower for both the flow rates, but the brake specific carbon monoxide (BSCO) and brake specific hydrocarbon (BSHC) emission are found to be higher for the flow rate of 240 g/h compared to 120 g/h of DEE and diesel at full load.
Technical Paper
2014-04-01
Piotr Bielaczyc, Andrzej Szczotka, Joseph Woodburn
Ethanol has long been a fuel of considerable interest for use as an automotive fuel in spark ignition (SI) internal combustion engines. In recent years, concerns over oil supplies, sustainability and geopolitical factors have lead multiple jurisdictions to mandate the blending of ethanol into standard gasoline. The impact of blend ethanol content on gaseous emissions has been widely studied; particulate matter emissions have received somewhat less attention, despite these emissions being regulated in the USA. Currently, in the EU particulate matter emissions from SI engines are partially regulated - only vehicles featuring direct injection SI engines are subject to emissions limits. A range of experiments was conducted to determine the impact of fuel ethanol content on the emissions of solid pollutants from Euro 5 passenger cars. All testing was conducted in BOSMAL's climate-controlled test facility, with tests performed at multiple ambient temperatures, including the two temperatures specified in EU legislation (+25°C, −7°C).
Technical Paper
2014-04-01
Karthik Nithyanandan, Han Wu, Ming Huo, Chia-Fon Lee
Abstract Alcohols, because of their potential to be produced from renewable sources and their characteristics suitable for clean combustion, are considered potential fuels which can be blended with fossil-based gasoline for use in internal combustion engines. As such, n-butanol has received a lot of attention in this regard and has 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. Acetone-Butanol-Ethanol (ABE) fermentation is one of the major methods to produce bio-butanol. The goal of this study is to investigate the combustion characteristics of the intermediate product in butanol production, namely ABE, and hence evaluate its potential as an alternative fuel. Acetone, n-butanol and ethanol were blended in a 3:6:1 volume ratio and then splash blended with pure ethanol-free gasoline with volumetric ratios of 0%, 20%, 40% to create various fuel blends. These blends were tested in a port-fuel injected spark-ignited (SI) engine and their performance was evaluated through measurements of in-cylinder pressure, and various exhaust emissions.
Technical Paper
2014-04-01
Narankhuu Jamsran, Ocktaeck Lim, Norimasa Iida
This study has been computationally investigated how the DME autoignition reactivity is affected by EGR and intake-pressure boost over various engine speed. CHEMKIN-PRO was used as a solver and chemical-kinetics mechanism for DME was utilized from Curran's model. We examined first the influence of EGR addition on autoignition reactivity using contribution matrix. Investigations concentrate on the HCCI combustion of DME at wide ranges of engine speeds and intake-pressure boost with EGR rates and their effects on variations of autoignition timings, combustion durations in two-stage combustion process in-detail including reaction rates of dominant reactions involved in autoignition process. The results show that EGR addition increases the combustion duration by lowering reaction rates. It was also found that autoignition timings were very sensitive to boost pressure due to boost pressure enhances the reactivity of intermediate species but combustion durations dominantly depend on the EGR addition.
Technical Paper
2014-04-01
Jing Gong, Jian Cai, Chenglong Tang
Propanol isomers are oxygenated fuels and have higher octane number and energy density compared to methanol and ethanol. In recent years, with the development of fermentation method, propanol isomers have gained more attention as engine additive to reduce the emission and the consumption of traditional fossil fuels. In this study, Hydrocarbon (HC), carbon monoxide (CO) and particulate matter (PM) emission characteristic of propanol isomers/gasoline blends were comparatively investigated at different blending ratios (0, 10, 20, 40 and 100) combined with exhaust gas recirculation (EGR) in a spark-ignition engine. The number distribution of particulate matter emission is mainly studied in addition to the particulate matter mass distribution. Results show that pure propanol isomers yield significantly different emission characteristics compared to the other blends. With the increase of blending ratio, CO emission shows a decreased trend while unidentified HC emissions are observed except pure propanol isomers.
Technical Paper
2014-04-01
Robert L. Russell, Kent Johnson, Thomas Durbin, Nicole Davis, James Lents
Abstract Engine manufacturers have explored many routes to reducing the emissions of harmful pollutants and conserving energy resources, including development of after treatment systems to reduce the concentration of pollutants in the engine exhaust, using alternative fuels, and using alternative fuels with after treatment systems. Liquefied petroleum gas (LPG) is one alternative fuel in use and this paper will discuss emission measurements for several LPG vehicles. Regulated emissions were measured for five school buses, one box truck, and two small buses over a cold start Urban Dynamometer Driving Schedule (CS_UDDS), the Urban Dynamometer Driving Schedule (UDDS), and the Central Business District (CBD) cycle. In general, there were no significant differences in the gas phase emissions between the UDDS and the CBD test cycles. For the CS-UDDS cycle the total hydrocarbons and non-methane hydrocarbon emissions are higher than they are from the UDDS cycle. Methane and carbon monoxide emissions are also higher, but the difference isn't as pronounced.
Technical Paper
2014-04-01
George Karavalakis, Daniel Short, Diep Vu, Mark Villela, Robert Russell, Heejung Jung, Akua Asa-Awuku, Thomas Durbin
Gasoline direct injection (GDI) engines have improved thermodynamic efficiency (and thus lower fuel consumption) and power output compared with port fuel injection (PFI) and their penetration is expected to rapidly grow in the near future in the U.S. market. In addition, the use of alternative fuels is expanding, with a potential increase in ethanol content beyond the current 10%. Increased emphasis has been placed on butanol due to its more favorable fuel properties, as well as new developments in production processes. This study explores the influence of mid-level ethanol and iso-butanol blends on criteria emissions, gaseous air toxics, and particulate emissions from two wall-guided gasoline direct injection passenger cars fitted with three-way catalysts. Emission measurements were conducted over the Federal Test Procedure (FTP) driving cycle on a chassis dynamometer. This study utilized seven fuels with varying ethanol and iso-butanol contents, including E10, E15, E20, Bu16, Bu24, Bu32, and a mixture of E20 and Bu16 resulting in E10/Bu8.
Technical Paper
2014-04-01
Joseph Kazour, Bizhan Befrui, Harry Husted, Michael Raney, Daniel Varble
Abstract Innovative nozzle hole shapes for inwardly opening multi-hole gasoline direct injectors offer opportunities for improved mixture formation and particulate emissions reduction. Compared to increased fuel pressure, an alternative associated with higher system costs and increased pumping work, nozzle hole shaping simply requires changes to the injector nozzle shape and may have the potential to meet Euro 6 particulate regulations at today's 200 bar operating pressure. Using advanced laser drilling technology, injectors with non-round nozzle holes were built and tested on a single-cylinder engine with a centrally-mounted injector location. Particulate emissions were measured and coking deposits were imaged over time at several operating fuel pressures. This paper presents spray analysis and engine test results showing the potential benefits of alternative non-round nozzle holes in reducing particulate emissions and enhancing robustness to coking with various operating fuel pressures.
Technical Paper
2014-04-01
Shubham Sharma, Naveen Kumar, Sambhav Jain, Sidhant Kumar
Abstract The present consumption rates and heavy dependence on fossil fuels pose a humongous threat to the environment. The increased pollution in urban areas is already causing serious sociological, ecological and economic implications. The issue of energy security led governments and researchers to look for alternate means of renewable and environment friendly fuels. Biodiesel has been one of the promising, and economically viable alternatives. The biodiesels are reported to cause reduction in CO, HC and PM emissions. However, NOx emissions are increased in case of biodiesel in CI engine. Therefore, a Urea-SCR over Fe-ZSM5 honeycomb substrate (400cpsi) zeolite catalyst after treatment system is an effective technology to reduce emissions for biodiesel applications. Exhaust gases pass through the catalyst and reactions take place along its surface, consequently converting NOx into nitrogen and H2O. This conversion compliments the functioning of fish oil biodiesel in reducing the overall emissions.
Technical Paper
2014-04-01
Bernhard Kern, Stephanie Spiess, Joerg Michael Richter
Abstract With the growing awareness about the presence of fine/ultra fine particulates in the ambient air and their negative impact on climate and health, some regions of the world have started to look closer at the contribution of road traffic. Since Gasoline engines, in particular when injecting fuel directly into the combustion chamber, proved to emit relevant numbers of particulates, even hardly visible, the growing share of Gasoline DI engines and their small size of particulate emissions is a concern. To address the same, the EU has already set limits for the particulate number with EU6 from 2015 onwards. The US considers setting challenging limits by particulate mass. Since mass of ultra fine particulates is very low and difficult to measure, experts investigate if a measurement by number might better address the particular concern. The implementation of a coated Particulate Filter enables meeting not only basic demands during traditional emission test cycles. Also the particulate emissions during highly transient and high load driving conditions are reduced effectively.
Technical Paper
2014-04-01
Ireneusz Pielecha, Przemyslaw Borowski, Wojciech Cieslik
Abstract The current paper is a continuation of research on fuel atomization presented in SAE 2012-01-1662. The influence of varied position of the injector inside the combustion chamber on combustion, toxic compounds formation and exhaust emission were investigated. The simulation research (injection and combustion with NO formation) was supported with the model using the FIRE 2010 software by AVL. Modelling studies of toxic compounds formation were compared with the results of measurements on single-cylinder AVL 5804 engine. There thermodynamic evaluation indicators and exhaust emission were made.
Technical Paper
2014-04-01
Johan Genberg, Petter Tornehed, Oivind Andersson, Kristina Stenstrom
Abstract PM in diesel exhaust has been given much attention due to its adverse effect on both climate and health. As the PM emission levels are tightened, the portion of particles originating from the lubrication oil is likely to increase. In this study, exhausts from a biodiesel-fueled Euro 5 engine were examined to determine how much of the carbonaceous particles that originated from the fuel and the lubrication oil, respectively. A combination of three methods was used to determine the PM origin: chain length analysis of the hydrocarbons, determination of organic and elemental carbon (OC and EC), and the concentration of 14C found in the exhausts. It was found that the standard method for measuring hydrocarbons in PM on a filter (chain length analysis) only accounted for 63 % of the OC, meaning that it did not account for all non-soot carbon in the exhausts. Comparing the chain length method to the 14C-based method showed that the non-extractable organic carbon originated both from the oil and fuel.
Technical Paper
2014-04-01
Dongxian Song, Ning Jia, Xiangyang Guo, Xingxing Ma, Zhigang Ma, Dingwei Gao, Kejun Li, Haipeng Lai, Chunhui Zhang
Abstract Downsizing is regarded as a promising strategy to reduce the fuel consumption of gasoline engines. But downsized turbocharged engines need to take knocking into account to avoid engine damage. Low Pressure (LP) cooled exhaust gas recirculation (EGR) is an effective suppressant of knocking at boosted high load and EGR could reduce pumping loss at low loads. Both of them are helpful to improve fuel economy. In the research, a LP cooled EGR system is added to a 1.5L turbocharged PFI production gasoline engine and the compression ratio is changed from 9.3 to 11.5. The results show that the fuel reduction is 4.5% at 2000rpm 5bar (20% EGR ratio) and 9.7 % at 3000rpm 10bar (20% EGR ratio) compared with no EGR case. But at boosted high loads the fuel consumption is almost same to the production engine due to high compression ratio which results in severe knocking. In order to further reduce fuel consumption, the engine is operated in lean burn conditions. As we know, the lean operation could decrease NOX conversion efficiency of three-way catalytic (TWC), but the EGR could substantially reduce the emission of NOX.
Technical Paper
2014-04-01
Kar Mun Pang, Mehdi Jangi, Xue-Song Bai, Jesper Schramm
Abstract In this reported work, 2-dimsensional computational fluid dynamics studies of n-heptane combustion and soot formation processes in the Sandia constant-volume vessel are carried out. The key interest here is to elucidate how the chemical kinetics affects the combustion and soot formation events. Numerical computation is performed using OpenFOAM and chemistry coordinate mapping (CCM) approach is used to expedite the calculation. Three n-heptane kinetic mechanisms with different chemistry sizes and comprehensiveness in oxidation pathways and soot precursor formation are adopted. The three examined chemical models use acetylene (C2H2), benzene ring (A1) and pyrene (A4) as soot precursor. They are henceforth addressed as nhepC2H2, nhepA1 and nhepA4, respectively for brevity. Here, a multistep soot model is coupled with the spray combustion solver to simulate the soot formation/oxidation processes. Comparison of the results shows that the simulated ignition delay times and liftoff lengths have good agreements with the experimental measurements across wide range of operating conditions when the nhepC2H2 model is implemented.
Technical Paper
2014-04-01
Wei Jing, William Roberts, Tiegang Fang
Abstract The measurement of the two-color line of sight soot and KL factor for NO.2 diesel and jet-A fuels was conducted in an optical constant volume combustion chamber by using a high speed camera under 1000 K ambient temperature and varied oxygen concentration conditions. The ambient conditions were set as follows: four oxygen cases including 10%, 15%, 18% and 21% at 1000 K ambient temperature. KL factor and soot temperature were determined based on the two-color pyrometry technique using two band-pass filters with wavelengths of 650 nm and 550 nm. The results show that low soot temperature is observed in the upstream inner flame along the centerline, which is surrounded by high soot temperature regions, and a high KL factor is found in the same region with a low soot temperature. The results under different times suggest that soot temperature is higher for high O2 conditions during the entire flame development; meanwhile, both integrated KL factor and soot area decrease with the increase of O2 concentration.
Technical Paper
2014-04-01
Helmut Brunner, Mario Hirz
Abstract Increasing urbanization, the growing degree of motorization and traffic performance in urban areas and environmental aspects like greenhouse gas emissions (GHG) are the motivation for a detailed analysis of personal individual mobility in urban areas, which is presented in this study. In the first step, the publication examines a study of market potential of new small and lightweight vehicle concepts. A mobility inquiry conducted in a mid-sized European city enables an estimation of the potential user groups for alternative vehicle concepts for individual urban traffic. In a second step, the CO2 reduction potential of urban car concepts is simulated for a generic vehicle fleet. This fleet consists of conventional vehicles of various classes (subcompact, compact, mid-sized …) as well as new lightweight urban car concepts. A novel vehicle concept for urban transportation will be presented as well. A comparison with the simulation results of a conventional vehicle fleet shows the potential regarding CO2-reduction and a reduction of parking space by application of future-oriented vehicle concepts.
Technical Paper
2014-04-01
Raouf Mobasheri, Seyed Alireza Khabbaz
Abstract Exhaust Gas Recirculation (EGR) is an effective pre-treatment technique, which has been widely used to decrease the amount of the oxides of nitrogen (NOx) emission from diesel engines. However, the use of high EGR rates leads to the reduction in oxygen availability in the burning regions of the combustion chamber which impairs the soot oxidation process. Consequently, higher soot generated by EGR leads to long-term usage problems inside the engines such as higher carbon deposits, lubricating oil degradation and enhanced engine wear. In this study, CFD modeling has been carried out to analyze the effects of high EGR rates in conjunction with optimum multiple injection strategies. A heavy-duty DI Diesel engine has been modeled to study the engine performance and emissions with various EGR rates (from 0% to 40%). The selected operating points have been achieved with the same injection profile including a main and post injection for all considered cases. The results showed the effectiveness of multiple injections at controlling soot emission under high EGR conditions.
Technical Paper
2014-04-01
Joohan Kim, Gyujin Kim, Hoon Lee, Kyoungdoug Min
Abstract Direct-injection spark-ignition (DISI) engines are regarded as a promising technology for the reduction of fuel consumption and improvement of engine thermal efficiency. However, due to direct injection, the shortened fuel-air mixing duration leads to a spatial gradient of the equivalence ratio, and these locally rich regions cause the formation of particulate matter. In the current study, numerical investigations on pollutant formation in a DISI engine were performed using combined flamelet models for premixed and diffusion flames. The G-equation model for partially premixed combustion was improved by incorporating the laminar flamelet library. Gasoline fuel was represented as a ternary mixture of gasoline surrogate and its laminar flame speeds were obtained under a wide range of engine operating conditions. For the flame propagation in a partially premixed condition, the presumed shape of the probability density function approach was adopted, whereas the burned gas compositions were determined from the steady laminar flamelet library.
Technical Paper
2014-04-01
May Yen, John Abraham
Abstract In this work, computations of reacting diesel jets, including soot and NO, are carried out for a wide range of conditions by employing a RANS model in which an unsteady flamelet progress variable (UFPV) sub-model is employed to represent turbulence/chemistry interactions. Soot kinetics is represented using a chemical mechanism that models the growth of soot precursors starting from a single aromatic ring by hydrogen abstraction and carbon (acetylene) addition and NO is modeled using the kinetics from a sub-mechanism of GRI-Mech 3.0. Tracer particles are used to track the residence time of the injected mass in the jet. For the soot and NO computations, this residence time is used to track the progression of the soot and NO reactions in time. The conditions selected reflect changes in injection pressure, chamber temperature, oxygen concentration, and density, and orifice diameter. As reported in prior work, the UFPV model predicts the ignition delay and flame lift-off height within about 25% of reported measurements.
Technical Paper
2014-04-01
Haichun Yao, Baigang Sun, Huayu Tian, Qinghe Luo, Hongyang Tang
Abstract NOx are the only harmful emissions of hydrogen internal combustion engine. EGR is one of the effective methods to reduce NOx. The traditional EGR is not suitable for hydrogen internal combustion engine. Therefore, the study of influence of hot EGR on hydrogen internal combustion engine is important. A 2.0L hydrogen internal combustion engine with hot EGR system model is employed to optimize the diameter and position of hot EGR based on a simulation analysis. The result shows that both of the combustion temperature and NOx increase as EGR increases due to the rise of intake temperature for low load condition, for heavy load, with the increase of EGR rate, NOx emissions decreases slightly before the mixture equivalence ratio comes to 1and then dropped significantly after the mixture equivalence ratio greater than 1. Unburned hydrogen in TWC has the effect of reducing NOx after catalysts decrease largely. Hydrogen engine combustion characteristics with hot EGR was analyzed, it suggests that EGR hasn't any benefit on combustion and NOx emission under low load condition; however, a significant amount reduce of NOx can be achieved under a rich condition (equivalence ratio greater than 1) by adjusting the EGR rate for high load condition with sacrificing power output slightly.
Technical Paper
2014-04-01
Thomas Wallner, Andrew Ickes, Jeff Wasil, James Sevik, Scott Miers
Abstract This study evaluates iso-butanol as a pathway to introduce higher levels of alternative fuels for recreational marine engine applications compared to ethanol. Butanol, a 4-carbon alcohol, has an energy density closer to gasoline than ethanol. Isobutanol at 16 vol% blend level in gasoline (iB16) exhibits energy content as well as oxygen content identical to E10. Tests with these two blends, as well as indolene as a reference fuel, were conducted on a Mercury 90 HP, 4-stroke outboard engine featuring computer controlled sequential multi-port Electronic Fuel Injection (EFI). The test matrix included full load curves as well as the 5-mode steady-state marine engine test cycle. Analysis of the full load tests suggests that equal full load performance is achieved across the engine speed band regardless of fuel at a 15-20°C increase in exhaust gas temperatures for the alcohol blends compared to indolene. This increase as well as the observed 2.5-3% point improvement in brake thermal efficiency of both alcohol blends compared to the reference fuel are caused by changes in air/fuel ratio; an effect ultimately attributable to the open loop engine control strategy.
Technical Paper
2014-04-01
Donald Selmanaj, Harald Waschl, Michael Schinnerl, Sergio Savaresi, Luigi del Re
Abstract Especially in view of more and more stringent emission legislation in passenger cars it is required to reduce the amount of pollutants. In the case of Diesel engines mainly NOx and PM are emitted during engine operation. The main influence factors for these pollutants are the in-cylinder oxygen concentration and the injected fuel amount. Typically the engine control task can be divided into two separate main parts, the fuel and the air system. Commonly air system control, consisting of a turbocharger and exhaust gas recirculation control, is used to provide the required amount of oxygen and address the emission targets, whereas the fuel is used to provide the desired torque. Especially in transient maneuvers the different time scales of both systems can lead to emission peaks which are not desired. Against this background in this work instead of the common way to address the air system, the fuel system is considered to reduce emission peaks during transients. The idea is to start from a base calibration and adapt the injection parameters, like start and amount of pilot and main injection, to reduce transient emission peaks.
Technical Paper
2014-04-01
Yong-Wha Kim, Michiel Van Nieuwstadt, Greg Stewart, Jaroslav Pekar
Abstract This paper presents the application of model predictive control (MPC) to DOC temperature control during DPF regeneration. The model predictive control approach is selected for its advantage - using a model to optimize control moves over horizon while handling constraints. Due to the slow thermal dynamics of the DOC and DPF, computational bandwidth is not an issue, allowing for more complex calculations in each control loop. The control problem is formulated such that all the engine control actions, other than far post injection, are performed by the existing production engine controller, whereas far post injection is selected as the MPC manipulated variable and DOC outlet temperature as the controlled variable. The Honeywell OnRAMP Design Suite (model predictive control software) is used for model identification, control design and calibration. The paper includes description of the DPF regeneration process, model identification and validation results, control design and trade-off analysis and experimental validation of the controller on a Ford Superduty diesel truck.
Technical Paper
2014-04-01
Jean-Claude Habumuremyi
Since 2004, INERGY is working on the development of SCR (Selective Catalytic Reduction) system Components and controls to enable the reduction of NOx (Nitrogen Oxides) in the exhaust gas using an aqueous urea solution. This paper is focused on the pump control strategy. In this paper, we modelled an INERGY SCR pump system (gear pump, DC motor, line and injector) used. Then we considered PID (Proportional-Integral-Derivative) controllers since they are common in the automotive industry. We developed 4 controllers to achieve the necessary system function which include: line filling, pressure build-up, pressure hold-up, and purge. Windup introduced by saturation of the motor command and transition between the controllers were taken into account during development. We tested different anti-windup approaches on this model. We derived lessons regarding the overshoot, the rise time and the performance of the different anti-windup techniques. Then we showed the results of anti-windup methods applied on INERGY 1st and 2nd generation SCR systems
Technical Paper
2014-04-01
Karthikeyan N, Anish Gokhale, Narendra Bansode
Abstract The Continuous Variable Transmission (CVT) in scooters is used to transmit the power from the engine to the wheels. The CVT transmission consists of a drive pulley and a driven pulley connected to each other through a belt. The centrifugal clutch is attached to the rear pulley which transmits the power to the wheel. The engagement and disengagement of the clutch generates heat and friction heat is generated between the belt and pulley, thereby requiring continuous external cooling for its safe operation. A centrifugal fan is employed for cooling of the CVT belt. Since the cooling fan takes air from atmosphere, there is always a possibility of dust from the atmosphere entering the system, which might cause wear of pulley and belt, thereby decreasing the performance of the transmission system. The objective of the work is to analyze the dust ingress pattern in to CVT housing. The work aims at simulating the possible conditions for dust entry into the CVT housing for a complete scooter and the study of different design proposals to minimize the dust entry without compromising the cooling requirement of CVT.
Technical Paper
2014-04-01
Lennert Sterken, Lennart Lofdahl, Simone Sebben, Tim Walker
Abstract Under a global impulse for less man-made emissions, the automotive manufacturers search for innovative methods to reduce the fuel consumption and hence the CO2-emissions. Aerodynamics has great potential to aid the emission reduction since aerodynamic drag is an important parameter in the overall driving resistance force. As vehicles are considered bluff bodies, the main drag source is pressure drag, caused by the difference between front and rear pressure. Therefore increasing the base pressure is a key parameter to reduce the aerodynamic drag. From previous research on small-scale and full-scale vehicles, rear-end extensions are known to have a positive effect on the base pressure, enhancing pressure recovery and reducing the wake area. This paper investigates the effect of several parameters of these extensions on the forces, on the surface pressures of an SUV in the Volvo Cars Aerodynamic Wind Tunnel and compares them with numerical results. To decrease the dependency of other effects within the engine bay and underbody, the SUV has been investigated in a closed-cooling configuration with upper and lower grille closed and with a smoothened underbody.
Technical Paper
2014-04-01
Essam F. Abo-Serie, Mohamed Sherif, Dario Pompei, Adrian Gaylard
Abstract A potentially important, but inadequately studied, source of passengers' exposure to pollutants when a road vehicle is stationary, with an idling engine, results from the ingestion of a vehicle's own exhaust into the passenger compartment through the HVAC intake. We developed and applied a method to determine the fraction of a vehicle's exhaust entering the cabin by this route. Further the influence of three parameters: ambient tail-wind speed, vehicle ground clearance and tail pipe angle, is assessed. The study applies Computational Fluid Dynamic (CFD) simulation to the distribution of exhaust gasses around a vehicle motorized with a 2.2 liter Diesel engine. The simulation employs efficient meshing techniques and realistic loading conditions to develop a general knowledge of the distribution of the gasses in order to inform engineering design. The results show that increasing tail-wind velocity, tail-pipe angle and ground clearance reduces the presence of CO and NO at the HVAC intake.
Technical Paper
2014-04-01
Prashant Khapane, Uday Ganeshwade
Abstract Vehicle water wading capability refers to vehicle functional part integrity (e.g. engine under-tray, bumper cover, plastic sill cover etc.) when travelling through water. Wade testing involves vehicles being driven through different depths of water at various speeds. The test is repeated and under-body functional parts are inspected afterwards for damage. Lack of CAE capability for wading equates to late detection of failure modes which inevitably leads to expensive design change, and potentially affects program timing. It is thus of paramount importance to have a CAE capability in this area to give design loads to start with. Computational fluid dynamics (CFD) software is used to model a vehicle travelling through water at various speeds. A non-classical CFD approach was deemed necessary to model this. To validate the method, experimental testing with a simplified block was done and then verified with CFD modelling. The simple rectangular block at two different speeds and three immersion depths in water was utilized for the purpose.
Technical Paper
2014-04-01
Kelly Daly Flynn, Ionut C. Harta, J. David Schall
Tribological performance of tungsten sulfide (WS2) nanoparticles, microparticles and mixtures of the two were investigated. Previous research showed that friction and wear reduction can be achieved with nanoparticles. Often these improvements were mutually exclusive, or achieved under special conditions (high temperature, high vacuum) or with hard-to-synthesize inorganic-fullerene WS2 nanoparticles. This study aimed at investigating the friction and wear reduction of WS2 of nanoparticles and microparticles that can be synthesized in bulk and/or purchased off the shelf. Mixtures of WS2 nanoparticles and microparticles were also tested to see if a combination of reduced friction and wear would be achieved. The effect of the mixing process on the morphology of the particles was also reported. The microparticles showed the largest reduction in coefficient of friction while the nanoparticles showed the largest wear scar area reduction. Mixtures of nanoparticles and microparticles did not provide the desired combination of significant friction and wear reductions.
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