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Viewing 1 to 30 of 5743
2015-01-14
Technical Paper
2015-26-0178
Usman Ali Mohammed, Nitin Gokhale, Sujit Pardeshi, Uday Gokhale, M N Kumar
The stringent emission norms and increasing demand for engines with higher power density lead to an extensive investigation of parameters affecting combustion performance. Recent emission norms have forced the engine manufacturers to reduce the Particulate matter (PM) emissions along with other emissions substantially. In order to achieve lo PM emissions the lubrication oil consumption need to be controlled by optimizing piston group design with low liner bore distortion. Bore Distortion is the deviation of actual profile from perfect circular profile at any plane perpendicular to axis of cylinder. Liner bore distortion in engines causes number of problems like deterioration of piston ring performance, liner-ring conformability issues, high lubricating oil consumption and emissions.
2015-01-14
Technical Paper
2015-26-0030
Naresh G. Gandhi, Nitin Gokhale, Yogesh Aghav, M N Kumar
Abstract Indian emission norms for stationary Gensets are upgraded from CPCB I to CPCB II. These new emission norms call for a significant change in emission limits. CPCB II emission norms call for 62% reduction in NOx+HC and 33% reduction in particulates for engines above 75 kW up to 800 kW power range compared to existing CPCB I norms. CPCB II norms are more stringent as compared to European Stage IIIA and CEV BS III. To meet equivalent emission norms in US and Europe most of the engine manufacturers have used Common Rail Direct Injection (CRDI) or electronic unit injection as the fuel injection technology. This paper describes mechanical fuel injection solution for meeting CPCB II emission norms on engines between 93 kW up to 552 kW with acceptable fuel consumption values. The paper presents simulation and experimentation work carried out to achieve the norms for the said power ratings.
2015-01-14
Technical Paper
2015-26-0015
N Anandaraj
Abstract Fuel level sensor is a device to indicate the level of the fuel in fuel tank fitted in an automobile. This will have features to communicate the fuel level to the dashboard of the vehicle and is of significant attention to the driver during vehicle usage. The advanced instrumentation provides a lot of information on the dashboard display such as information about fuel level, computing mileage, miles to go or miles to empty, fuel economy, average mileage, etc. Presently, the float arm type with Thick Film Resistor(TFR) and Reed switch type fuel level sensors are being used. To have accurate information for computing, the present sensors are not supporting due to its limitations like nonlinearity, fluctuating output due to slosh, output variations in steps and not continuous. The measurement accuracy of the fuel level sensor needs to be focused to rely on the information available on the dashboard instrument.
2015-01-14
Technical Paper
2015-26-0028
S. Loganathan, P Esakkimuthu, M Srivatsan, M Anand
Oil pump is one of the important engine parasitic loads which takes up engine power through crankshaft to deliver oil flow rate according to engine demand to maintain required oil pressure. The proper functioning of oil pump along with optimum design parameters over various operating conditions is considered for required engine oil pressure. Pressure relief passage is also critical from design point of view as it maintains the oil pressure in the engine. Optimal levels of oil pressure and flow are very important for satisfied performance and lubrication of various engine parts. Low oil pressure will lead to seizure of engine and high oil pressure leads to failure of oil filters, gasket sealing, etc. Optimization of pressure relief passage area along with other internal systems will also reduce the power consumed by the pump.
2015-01-14
Technical Paper
2015-26-0154
Anand Ramalingam, Saravanakumar Thangamani
In the highly competitive automotive industry, safety and robustness become indispensable. Vibration requirements and crash-worthiness of automotive components have become stringent over the years. Therefore designers are facing huge challenges for fulfilling both criteria as these requirements become contradictory in some applications. The Fuel Delivery Module (FDM) comprising flange and swirl pot assembly, is mounted on fuel tank. It pumps fuel from tank to the engine. Flange mounted on fuel tank opening, provides proper sealing. Swirl pot assembly comprises of fuel pump, pump holder and fuel level sensor. It is positioned inside the tank by two axially spring loaded struts connected to the flange. During crash, FDM undergoes sudden deceleration. Due to inertia, swirl pot assembly creates bending moment in the flange-strut interface. At such adverse condition, flange should not exhibit crack on the sealing side, as it might expose fuel in the fuel tank to the atmosphere.
2015-01-14
Technical Paper
2015-26-0046
Sukrut S Thipse, Shailesh B Sonawane, Ashwin F D' Souza, S D Rairikar, Kishor Kumar Kavathekar, Neelkanth V Marathe
Abstract CNG has long since been established as a front runner amongst other available alternative fuels. In India, its infrastructure and penetration far exceeds others. While other, more efficient alternatives are been researched, CNG has established itself in the market as the alternative fuel of choice for majority of Indians. CNG technology has evolved itself from the basic venturi system to the more efficient sequential injection system nowadays. While the efficiency of an engine using sequential injection CNG has increased, the inherent problem with respect to lower volumetric efficiency and hence less power still persists. Direct injection CNG technology is seen as the solution to this age old problem. In the older days, the lack of technological expertise in SI direct fuel injection provided a stumbling block for development of direct gas injection.
2015-01-01
Journal Article
2014-01-9053
Tobias Breuninger, Jürgen Schmidt, Helmut Tschoeke, Martin Hese, Andreas Kufferath, Frank Altenschmidt
The spray-guided combustion process offers a high potential for fuel savings in gasoline engines in the part load range. In this connection, the injector and spark plug are arranged in close proximity to one another, as a result of which mixture formation is primarily shaped by the dynamics of the fuel spray. The mixture formation time is very short, so that at the time of ignition the velocity of flow is high and the fuel is still largely present in liquid form. The quality of mixture formation thus constitutes a key aspect of reliable ignition. In this article, the spray characteristics of an outward-opening piezo injector are examined using optical testing methods under pressure chamber conditions and the results obtained are correlated with ignition behaviour in-engine. The global spray formation is examined using high-speed visualisation methods, particularly with regard to cyclical fluctuations.
2015-01-01
Journal Article
2014-01-9103
Waleed Faris, Hesham Rakha, Salah A. Elmoselhy
Vehicle analytical models are often favorable due to describing the physical phenomena associated with vehicle operation following from the principles of physics, with explainable mathematical trends and with extendable modeling to other types of vehicle. However, no experimentally validated analytical model has been developed as yet of diesel engine fuel consumption rate. The present paper demonstrates and validates for trucks and light commercial vehicles an analytical model of supercharged diesel engine fuel consumption rate. The study points out with 99.6% coefficient of determination that the average percentage of deviation of the steady speed-based simulated results from the corresponding field data is 3.7% for all Freeway cycles. The paper also shows with 98% coefficient of determination that the average percentage of deviation of the acceleration-based simulated results from the corresponding field data under negative acceleration is 0.12 %.
2014-11-11
Technical Paper
2014-32-0072
Kenta Sugimoto
Abstract Cost reduction is an important development goal for small motorcycles (1). As a way to reduce costs, we have developed an electronically controlled fuel injection (hereafter FI) system without a throttle position sensor (hereafter TPS). Ordinarily, the high throttle range is controlled and computed by TPS, and the low throttle range by manifold pressure sensor (hereafter MPS). The intake airflow is estimated with consistent high precision regardless of the engine load, and the basic fuel injection is executed accordingly. Also, transient correction monitors the size of TPS changes, to inject fuel immediately when a TPS change equal to or greater than a threshold value is detected. In our development, we replaced these functions with control by MPS. For calculation of basic fuel injection quantity by MPS, we carried on the conventional method. However, MPS transient correction control had some aspects with poor tracking.
2014-11-11
Technical Paper
2014-32-0073
Horizon Walker Gitano, Ray Chim, Jian Loh
Abstract Recent concern over air quality has lead to increasingly stringent emissions regulations on ever smaller displacement engines, resulting in the application of Electronic Fuel Injection (EFI) to the 100cc-200cc class 2-wheelers in many countries. In the pursuit of ever smaller and less expensive EFI systems a number of unique technologies are being explored, including resistive type oxygen sensors. In this paper we investigate the application of a prototype resistive oxygen sensor to a small motorcycle EFI system. Measurements of the exhaust system temperatures, and Air/Fuel Ratio (AFR) and resistive sensor response are carried out, and compared to the standard zirconia oxygen sensor to create an estimate of the sensor's in-use performance. Motorcycle performance data are compared using both a standard zirconia switching type oxygen sensor, and the new resistive type oxygen sensor to control the air/fuel ratio.
2014-11-11
Technical Paper
2014-32-0075
Kazuyoshi Shimatani
Abstract Various sensors including throttle position sensors (TPS), manifold pressure sensors (MPS), crank angle sensors, engine temperature sensors, and oxygen sensors are mounted in electronically controlled fuel injection (FI) systems to accurately regulate the air-fuel ratio according to the operating state and operating environment. Among these vehicle-mounted sensors, TPS has functions for detecting a fully-closed throttle and estimating intake air volume by the amount of throttle opening. Currently, we have conducted a study on transferring TPS functions into the MPS (manifold pressure sensor) in order to eliminate the TPS. Here we report on detecting a fully-closed throttle for achieving fuel cut control (FCC) and idle speed control (ISC) in fuel injection systems. We contrived a means for fully-closed throttle detection during ISC and controlling changes in the bypass opening during FCC in order to accurately judge each fully-closed throttle state via the manifold pressure.
2014-11-11
Technical Paper
2014-32-0083
Akihiko Azetsu, Hiroomi Hagio
Abstract The objective of this study is to understand the fundamental spray combustion characteristics of FAME mixed with diesel oil. To examine the phenomena in detail, diesel spray flame formed in a constant volume high pressure vessel was visualized and the flame temperature and the KL factor were analyzed by two color method of luminous flame. The FAMEs examined in this study are PME, RME and CME, and compared with the combustion characteristics of diesel oil. From the systematic experiments, it is confirmed that the ignition delay and combustion period of bio diesel fuels are almost equivalent with those of diesel oil. The flame temperature decreased slightly with the bio fuel. Furthermore the total KL factor, a measure of the amount of soot in flame, decreased drastically by using the bio diesel fuel in the order of the mass fraction of oxygen in the molecule.
2014-11-11
Journal Article
2014-32-0059
Antonio Agresta, Francesca Di Puccio, Paola Forte, Gabriele Benigni
Abstract NVH simulations for an automotive component industry represent a convenient mean to compare different solutions and make decisions on design choices based on the predictions of the component vibro-acoustic behavior. This paper presents the vibro-acoustic characterization and comparison of two fuel rail assemblies (FRAs) by mean of simulations in Ansys Workbench & LMS Virtual.Lab. These simulations required a preliminary finite element (FE) modal analysis on the FRAs. To verify the reliability of the FE models, an experimental modal analysis was performed on one of the two fuel rails in free-free condition. The correlation between FE and test models highlighted some differences: a sensitivity study proved that the differences depend on the modeling of some brazed joints. The results of the following NVH simulations were checked by performing an acoustic impact test on the two FRAs in free-free condition inside an anechoic chamber.
2014-11-11
Journal Article
2014-32-0062
Jonathan Tenenbaum, Michael Shapiro, Leonid Tartakovsky
Abstract The paper presents an analytical two-dimensional model of two-phase turbulent jets with focus on fuel sprays in internal combustion engines. The developed model allows prediction of the fuel spray parameters including local fuel concentration and mixture velocity. The model proposed in this paper is based on the single-phase steady-state laminar axisymmetric jet flow field solution by Schlichting. This solution is amended to include transport of the discontinuous fuel phase in a stagnant air in the limit of a dilute fuel concentration. This two-phase jet flow model admits a closed form analytical solution for the fuel concentration distribution. This solution is then applied to turbulent jet flow as per the approach described by Schlichting and in other studies, and used to predict point-wise properties of fuel sprays in internal combustion engines. The results of model simulations are compared with the available experimental data.
2014-11-11
Technical Paper
2014-32-0134
Giovanni Bonandrini, Rita Di Gioia, Luca Venturoli, Domenico Papaleo, Lucio Postrioti, Leonardo Zappalà
Abstract Diesel engine technology is continuously focused on higher performances and lower emission levels. Reduced costs and lower fuel consumption are key factors in engine development too, in particular for small diesel engine, both for on-road and non-road application. In order to fulfill emission legislation requirements, improve engine performance and reduce fuel consumption, nowadays the common rail injection system with electronic actuation is widely used in diesel engines. Nevertheless, conventional common rail system cost is quite high, mainly due to the complex indirect actuation of the injector, and the injector backflow leads to inefficiencies in the injection system. In this work an analysis of a medium pressure injection system for small diesel engines is presented, focusing on the achievable engine performances and emissions.
2014-11-11
Technical Paper
2014-32-0125
Mohd Al-Hafiz Mohd Nawi, Yoshiyuki Kidoguchi, Misato Nakagiri, Naoya Uwa, Yuzuru Nada, Seiji Miyashiro
Abstract High boosting technology is commonly applied to diesel engines in recent years. Amid this trend, the study of spray behavior at ignition delay period still plays an important role in diesel combustion. This study focuses on the effect of ambient condition on diesel spray. The study investigates both macro-scale and micro-scale dynamic behaviors of diesel spray affected by ambient density and temperature at early stage of injection. A study via dual nano-spark shadowgraph method and rapid compression machine has been carried out to simulate real diesel engine combustion and to further understand the dynamics behavior of droplet evaporation and size distribution at early stage of mixture formation in the chamber. The micro-scale images captured reveal a shape variation of branch-like structures formed at the spray boundary. The evaporation of droplets is also captured clearly in macro- and micro scale photographs under the condition of high temperature ambient.
2014-11-11
Journal Article
2014-32-0124
Keiya Nishida, Kuichun LI, Takeru Matsuo, Daisuke Shimo, Wu Zhang
Abstract Spray characteristics under very small injection amount injected by the hole-type nozzle for a D.I. Diesel engine were investigated using the spray test rig consisting a high-pressure and high-temperature constant volume vessel with optical accesses and a common rail injection system. The Laser Absorption Scattering (LAS) technique was used to visualize the liquid and vapor phase distributions in the evaporating spray. In the very small injection amount condition of the evaporating and free (no wall impingement) spray, the both spray tip penetration and spray angle are larger than those of the non-evaporating free spray. This tendency contradicts the previous observation of the diesel spray with large injection amount and the quasi steady state momentum theory. In the case of the spray impinging on a 2-dimensional piston cavity wall, the spray tip penetration of the evaporating spray is larger than that of the non-evaporating spray.
2014-11-11
Technical Paper
2014-32-0040
John Walters, Francois Brun
Abstract Stringent emissions legislation is being applied to small motorcycles and scooters around the world. This is forcing, gradually, the replacement of carburetors by electronic fuel injection (EFI) systems. The integration of this new technology creates new constraints on the engine and also on the vehicle. This study will provide an overview of these constraints and also technical solutions to reduce the impact on engine and vehicle. A special focus will be done on the fuel system, where the development of an advanced technology will be discussed in detail. This technology marks a break with the standard automotive fuel system architecture in order to fulfill the specific requirements of scooters and small motorcycles: low size, low weight, low energy demand, as well as simple integration.
2014-11-11
Technical Paper
2014-32-0041
Luigi Allocca, Alessandro Montanaro, Rita Di Gioia, Giovanni Bonandrini
Abstract In the next future, improvements of direct injection systems for spark-ignited engines are necessary for the potential reductions in fuel consumptions and exhaust emissions. The admission and spread of the fuel in the combustion chamber is strictly related to the injector design and performances, such as to the fuel and environmental pressure and temperature conditions. In this paper the spray characterization of a GDI injector under normal and flash-boiling injection conditions has been investigated. The paper is mainly focused both on the capability of the injection apparatus/temperatures controller system to realize flash-boiling conditions, and the diagnostic setup to catch the peculiarities of the spray behavior. The work aims reporting the spray characterization under normal and flash-boiling conditions.
2014-11-01
Journal Article
2014-01-9079
Yongming Bao, Qing Nian Chan, Sanghoon Kook, Evatt Hawkes
Abstract The spray development of ethanol, gasoline and iso-octane has been studied in an optically accessible, spark-ignition direct-injection (SIDI) engine. The focus is on how fuel properties impact temporal and spatial evolution of sprays at realistic ambient conditions. Two optical facilities were used: (1) a constant-flow spray chamber simulating cold-start conditions and (2) a single-cylinder SIDI engine running at normal, warmed-up operating conditions. In these optical facilities, high-speed Mie-scattering imaging is performed to measure penetrations of spray plumes at various injection pressures of 4, 7, 11 and 15 MPa. The results show that the effect of fuel type on the tip penetration length of the sprays depends on the injection conditions and the level of fuel jet atomisation and droplet breakup.
2014-10-13
Technical Paper
2014-01-2660
Jacek Hunicz, Pawel Kordos, Piotr Ignaciuk
Abstract A single cylinder research engine with negative valve overlap (NVO) and direct gasoline injection was run in a homogeneous charge compression ignition (HCCI) mode. The split fuel injection technique was used, where the first injection was applied during exhaust re-compression, while the second injection was applied at the beginning of main compression. The quantities of the fuel injected at the two timings were varied from the whole fuel injection during NVO to the whole fuel injection during the main compression event. These split fuel ratio sweeps were repeated both for a stoichiometric mixture and for a slightly lean mixture. In the study, NVO reactions were assessed via analysis of the exhaust-fuel mixture composition after the NVO period and referred to the main event combustion. The results showed that fuel injection during NVO resulted in the production of substantial quantities of auto-ignition promoting species, such as acetylene and formaldehyde.
2014-10-13
Journal Article
2014-01-2670
Xinyan Wang, Hua Zhao, Hui Xie, Bang-Quan He
Abstract SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In order to stabilize the hybrid combustion process, the port fuel injection (PFI) combined with gasoline direct injection (GDI) strategy is proposed in this study to form the in-cylinder fuel stratification to enhance the early flame propagation process and control the auto-ignition combustion process. The effect of bowl piston shapes and fuel injection strategies on the fuel stratification characteristics is investigated in detail using three-dimensional computational fluid dynamics (3-D CFD) simulations. Three bowl piston shapes with different bowl diameters and depths were designed and analyzed as well as the original flat piston in a single cylinder PFI/GDI gasoline engine.
2014-10-13
Technical Paper
2014-01-2673
Amine Labreche, Fabrice Foucher, Christine Rousselle
Abstract In this work, the first injection of gasoline was maintained at 30 CAD Before TDC and the second one was swept between 10 CAD Before TDC to 5 CAD After TDC, in order to demonstrate the ideal positioning of the second injection. The results showed that when it was placed near TDC, low emissions, acceptable noise and acceptable efficiencies could be obtained. The effect of EGR, simulated by N2 addition, was also studied. As expected, globally the effect of the EGR rate was to delay the combustion phasing and to decrease NOx emissions. The optimal EGR dilution rate was found to be 30% with respect to the cycle-to-cycle variation criterion (< 5%). Increasing the dilution rate increased HC, CO and PM emissions, due to a considerable delay in combustion phasing caused by the reduction in the fuel reaction rate and the in-cylinder lack of oxygen when the EGR rate reached 30%. The impact of the fuel mass distribution between the two injections was also considered.
2014-10-13
Journal Article
2014-01-2669
Jesus Benajes, Bernardo Tormos, Antonio Garcia, Javier Monsalve-Serrano
Abstract Along the last years, engine researchers are more and more focusing their efforts on the advanced low temperature combustion (LTC) concepts with the aim of achieving the stringent limits of the current emission legislations. In this regard, several studies based on highly premixed combustion concepts such as HCCI has been confirmed as a promising way to decrease drastically the most relevant CI diesel engine-out emissions, NOx and soot. However, the major HCCI drawbacks are the narrow load range, bounded by either misfiring (low load, low speed) or hardware limitations (higher load, higher speeds) and the combustion control (cycle-to-cylce control and combustion phasing). Although several techniques have been widely investigated in order to overcome these drawbacks, the high chemical reactivity of the diesel fuel remains as the main limitation for the combustion control.
2014-10-13
Technical Paper
2014-01-2681
Zufeng Bao, Xiaobei Cheng, Liang Qiu, Xingcun Luan
The performance of Partially Premixed Combustion (PPC) relies heavily on the proper mixing between the injected fuel and the in-cylinder gas mixture. This pre-mixing aims to eliminate over-rich regions where the mixture forms soot, and at the same time to avoid the NOX formation region by lowering the combustion temperature by introduction of a large amount of EGR The main effort of this paper focuses on investigating the characteristic of PPC combustion and a suitable injection strategy for achieving the PPC combustion mode. Two injection strategies (i.e. double and single injection) were investigated on a four-cylinder heavy-duty diesel engine operating at low, medium and high load conditions.
2014-10-13
Technical Paper
2014-01-2680
Martin Tuner, Thomas Johansson, Hans Aulin, Per Tunestal, Bengt Johansson, William Cannella
This work investigates the performance potential of an engine running with partially premixed combustion (PPC) using commercial diesel engine hardware. The engine was a 2.01 SAAB (GM) VGT turbocharged diesel engine and three different fuels were run - RON 70 gasoline, RON 95 Gasoline and MK1 diesel. With the standard hardware an operating range for PPC from idle at 1000 rpm up to a peak load of 1000 kPa IMEPnet at 3000 rpm while maintaining a peak pressure rise rate (PPRR) below 7 bar/CAD was possible with either RON 70 gasoline and MK1 diesel. Relaxing the PPRR requirements, a peak load of 1800 kPa was possible, limited by the standard boosting system. With RON 95 gasoline it was not possible to operate the engine below 400 kPa. Low pressure EGR routing was beneficial for efficiency and combined with a split injection strategy using the maximum possible injection pressure of 1450 bar a peak gross indicated efficiency of above 51% was recorded.
2014-10-13
Journal Article
2014-01-2677
Slavey Tanov, Robert Collin, Bengt Johansson, Martin Tuner
Abstract Partially Premixed Combustion (PPC) is used to meet the increasing demands of emission legislation and to improve fuel efficiency. PPC with gasoline fuels have the advantage of a longer premixed duration of fuel/air mixture which prevents soot formation at higher loads. The objective of this paper is to investigate the degree of stratification for low load (towards idle) engine conditions using different injection strategies and negative valve overlap (NVO). The question is, how homogenous or stratified is the partially premixed combustion (PPC) for a given setting of NVO and fuel injection strategy. In this work PRF 55 has been used as PPC fuel. The experimental engine is a light duty (LD) diesel engine that has been modified to single cylinder operation to provide optical access into the combustion chamber, equipped with a fully variable valve train system. Hot residual gases were trapped by using NVO to dilute the cylinder mixture.
2014-10-13
Journal Article
2014-01-2676
Takayuki Fuyuto, Masahiro Taki, Reiko Ueda, Yoshiaki Hattori, Hiroshi Kuzuyama, Tsutomu Umehara
Abstract An author's previous studies addressed a combustion system which reduces emissions, noise, and fuel consumption by using PCCI with the split injection of fuel. This concept relies on the premixed combustion of the first injected fuel and accelerated oxidation by the second injected fuel. Although this combustion system requires the optimization of the timing of the second injection, the details of how noise and emissions are reduced have not been elucidated. In this paper, the authors explain the mechanism whereby emissions and noise are reduced by the second injection. In-cylinder visualizations and numerical simulations both showed an increase in smoke and CO as the second injection timing was advanced, as induced by the inhibited oxidation of the rich flame. When the second injection timing is excessively retarded, the amount of soot forming around the near-nozzle increased.
2014-10-13
Journal Article
2014-01-2632
Clemens Brückner, Panagiotis Kyrtatos, Konstantinos Boulouchos
Abstract New emission legislations applicable in the near future to sea-going vessels, off-road and off-highway vehicles require drastic nitric oxides emission reduction. A promising approach to achieve part of this decrease is charge air temperature reduction using Miller timing. However, it has been shown in literature that the reduction potential is limited, achieving a minimum in NOx emissions at a certain end-of-compression temperature. Further temperature reduction has shown to increase NOx emissions again. Some studies have shown that this increase is correlated to an increased amount of premixed combustion. In this work, the effects of pilot injection on engine out NOx emissions for very early intake valve closure (i.e. extreme Miller), high boost pressures and cold end-of-compression in-cylinder conditions are investigated.
2014-10-13
Technical Paper
2014-01-2634
Naoto Horibe, Tatsuya Komizo, Takashi Sumimoto, Hao Wang, Takuji Ishiyama
Abstract A series of experiments using a single-cylinder direct injection diesel engine was conducted to investigate the smoke reduction effect of post injection while varying numerous parameters: the post-injection quantity, post-injection timing, injection pressure, main-injection timing, intake pressure, number of injection nozzle orifices, and combustion chamber shape. The experiments were performed under a fixed NOx emission condition by selecting the total injection quantities needed to obtain the predetermined smoke emission levels without post injection. The smoke reduction effects were compared when changing the post injection timing for different settings of the above parameters, and explanations were found for the measured smoke emission trends. The results indicate that close post injection provides lower smoke emission for a combination of a reentrant combustion chamber and seven-hole nozzle.
Viewing 1 to 30 of 5743