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Viewing 1 to 30 of 42298
2011-05-17
Journal Article
2011-01-1649
Andrew J. Morello, Jason R. Blough, Jeffrey Naber, Libin Jia
Research into the estimation of diesel engine combustion metrics via non-intrusive means, typically referred to as “remote combustion sensing” has become an increasingly active area of combustion research. Success in accurately estimating combustion metrics with low-cost non-intrusive transducers has been proven and documented by multiple sources on small scale diesel engines (2-4 cylinders, maximum outputs of 67 Kw, 210 N-m). This paper investigates the application of remote combustion sensing technology to a larger displacement inline 6-cylinder diesel with substantially higher power output (280 kW, 1645 N-m) than previously explored. An in-depth frequency analysis has been performed with the goal of optimizing the estimated combustion signature which has been computed based upon the direct relationship between the combustion event measured via a pressure transducer, and block vibration measured via accelerometers.
2011-05-17
Technical Paper
2011-01-1644
Greg Uhlenhake, Ahmet Selamet, Kevin Fogarty, Kevin Tallio, Philip Keller
A cold turbocharger test facility was designed and developed at The Ohio State University to measure the performance characteristics under steady state operating conditions, investigate unsteady surge, and acquire acoustic data. A specific turbocharger is used for a thermodynamic analysis to determine the capabilities and limitations of the facility, as well as for the design and construction of the screw compressor, flow control, oil, and compression systems. Two different compression system geometries were incorporated. One system allows compressor performance measurements left of the surge line, while the other incorporates a variable-volume plenum. At the full plenum volume and a specific impeller tip speed, the temporal variation of the compressor inlet and outlet and the plenum pressures as well as the turbocharger speed is presented for stable, mild surge, and deep surge operating points.
2011-05-17
Technical Paper
2011-01-1660
Ienkaran Arasaratnam, Saeid Habibi, Christopher Kelly, Tony J. Fountaine, Jimi Tjong
Advanced engine test methods incorporate several different sensing and signal processing techniques for identifying and locating manufacturing or assembly defects of an engine. A successful engine test method therefore, requires advanced signal processing techniques. This paper introduces a novel signal processing technique to successfully detect a faulty internal combustion engine in a quantitative manner. Accelerometers are mounted on the cylinder head and lug surfaces while vibration signals are recorded during engine operation. Using the engine's cam angular position, the vibration signals are transformed from the time domain to the crank-angle domain. At the heart of the transformation lies interpolation. In this paper, linear, cubic spline and sinc interpolation methods are demonstrated for reconstructing vibration signals in the crank-angle domain.
2011-05-17
Technical Paper
2011-01-1636
Chiharu Togashi PhD, Mitsuo Nakano PhD, Masao Nagai PhD
A lot of countermeasures have been developed in order to reduce interior noise. For example, improvements of rubber mount characteristics and other measures have been implemented. Recently electromagnetic active engine mounts based on a hydraulic engine mount have been developed. They are significantly effective for the reduction of the booming noise which is unpleasant for passengers. Although the LMS algorithm has been generally used for the active control, it has been used only for reducing booming noise. The authors developed a new control method in order to reduce not only the booming noise but also the noise and the vibration over wide frequency band for comfortable vehicle interior space. The authors studied the method which determines the feedback gain according to various conditions by modifying LMS algorithm. In this modified LMS algorithm, only an error signal was used as an input signal.
2011-05-17
Technical Paper
2011-01-1565
Jennifer Durfy, Sang-Bum Hong, Bibhu Mahanta
As fuel prices continue to be unstable the drive towards more fuel efficient powertrains is increasing. For engine original equipment manufacturers (OEMs) this means engine downsizing coupled with alternative forms of power to create hybrid systems. Understanding the effect of engine downsizing on vehicle interior NVH is critical in the development of such systems. The objective of this work was to develop a vehicle model that could be used with analytical engine mount force data to predict the vehicle interior noise and vibration response. The approach used was based on the assumption that the largest contributor to interior noise and vibration below 200 Hz is dominated by engine mount forces. An experimental transfer path analysis on a Dodge Ram 2500 equipped with a Cummins ISB 6.7L engine was used to create the vehicle model. The vehicle model consisted of the engine mount forces and vehicle paths that define the interior noise and vibration.
2011-05-17
Technical Paper
2011-01-1563
Ki-Hwa Lee, Chung-Guen Nam, Hyung-Shin KIm, Dong-Kyu Yoo, Koo-Tae Kang
A comprehensive investigation was carried out in order to develop the idle sound quality for diesel V6 engine when the engine development process is applied to power-train system, which included new 8-speed automatic transmission for breaking down the noise contribution between the mechanical excitation and the combustion excitation. First of all, the improvement of dynamic characteristic can be achieved during the early stages of the engine development process using experimental modal analysis (EMA) & the robust design of each engine functional system. In addition, the engine structural attenuation (SA) is enhanced such that the radiated combustion noise of the engine can be maintained at a target level even with an increased combustion excitation. It was found that the engine system has better parts and worse parts in frequency range throughout the SA analysis. It is important that weak points in the system should be optimized.
2011-05-17
Journal Article
2011-01-1562
Tamer Elnady, Sara Elsaadany, D. W. Herrin
Diesel engines produce harmful exhaust emissions and high exhaust noise levels. One way of mitigating both exhaust emissions and noise is via the use of after treatment devices such as Catalytic Converters (CC), Selective Catalytic Reducers (SCR), Diesel Oxidation Catalysts (DOC), and Diesel Particulate Filters (DPF). The objective of this investigation is to characterize and simulate the acoustic performance of different types of filters so that maximum benefit can be achieved. A number of after treatment device configurations for trucks were selected and measured. A measurement campaign was conducted to characterize the two-port transfer matrix of these devices. The simulation was performed using the two-port theory where the two-port models are limited to the plane wave range in the filter cavity.
2011-05-17
Technical Paper
2011-01-1566
Thomas Reinhart, Mitchel Smolik
Several new or significantly upgraded heavy duty truck engines are being introduced in the North American market. One important aspect of these new or revised engines is their noise characteristics. This paper describes the noise related characteristics of the new DD15 engine, and compares them to other competitive heavy truck engines. DD15 engine features relevant to noise include a rear gear train, isolated oil pan and valve cover, and an amplified high pressure common rail fuel system. The transition between non-amplified and amplified common rail operation is shown to have a significant noise impact, not unlike the transition between pilot injection and single shot injection in some other engines.
2011-05-17
Technical Paper
2011-01-1591
Kumbhar S. Mansinh, Atul Miskin, Vishal Vasantrao Chaudhari, Ashish Rajput
The noise and vibration performance of diesel fueled automotives is critical for overall customer comfort. The stationary vehicle with engine running idle (Vehicle Idle) is a very common operating condition in city driving cycle. Hence it is most common comfort assessment criteria for diesel vehicles. Simulations and optimization of it in an early stage of product development cycle is priority for all OEMs. In vehicle idle condition, powertrain is the only major source of Noise and Vibrations. The key to First Time Right Idle NVH simulations and optimization remains being able to optimize all Transfer paths, from powertrain mounts to Driver Ear. This Paper talks about the approach established for simulations and optimization of powertrain forces entering in to frame by optimizing powertrain mount hard points and stiffness. Powertrain forces optimized through set process are further used to predict the vehicle passenger compartment noise and steering vibrations.
2011-05-17
Journal Article
2011-01-1527
Rick Dehner, Ahmet Selamet, Philip Keller, Michael Becker
The unsteady surge behavior of a turbocharger compression system is studied computationally by employing a one-dimensional engine simulation code. The system modeled represents a new turbocharger test stand consisting of a compressor inlet duct breathing from ambient, a centrifugal compressor, an exit duct connected to an adjustable-volume plenum, followed by another duct which incorporates a control valve and an orifice flow meter before exhausting to ambient. Characteristics of mild and deep surge are captured as the mass flow rate is reduced below the stability limit, including discrete sound peaks at low frequencies along with their amplitudes in the compressor (downstream) duct and plenum. The predictions are then compared with the experimental results obtained from the cold stand placed in a hemi-anechoic room.
2011-05-17
Technical Paper
2011-01-1530
Uday Senapati, Graham Evans, Aaron Hankinson
The drive for lower CO₂ emissions places ever greater demand on cooling dissipation for a multi-cylinder internal combustion engine. This challenge has increased the requirements of the engine cooling system, particularly in countries where high ambient temperatures prevail and HVAC usage is high. Environmental necessity coupled with market demands have resulted in cars which emit a higher level of cooling fan noise which is intrusive in an urban environment and objectionable to customers. Conventional quantification of noise using traditional units and metrics was found to be insufficient for effective Sound Quality analysis. To assist Bentley Motors, a high performance luxury vehicle manufacturer, with its brand cachet and its commitment to the environment and customer, a new sound metric analysis has been devised to help the business deliver an ever-quieter exterior power unit cooling system.
2011-05-17
Technical Paper
2011-01-1532
Charlie Teng, Fumin Pan, Jemai Missaoui, Scott Deraad
Turbocharged gasoline engines are typically equipped with a compressor anti-surge valve or CBV (compressor by-pass valve). The purpose of this valve is to release pressurized air between the throttle and the compressor outlet during tip-out maneuvers. At normal operating conditions, the CBV is closed. There are two major CBV mounting configurations. One is to mount the CBV on the AIS system. The other is to mount the CBV directly on the compressor housing, which is called an integrated CBV. For an integrated CBV, at normal operating conditions, it is closed and the enclosed passageway between high pressure side and low pressure side forms a “side-branch” in the compressor inlet side (Figure 12). The cavity modes associated with this “side-branch” could be excited by shear layer flow and result in narrow band flow noises.
2011-05-17
Technical Paper
2011-01-1536
Mohammad Kazem Baghi Abadi, Ali Hajnayeb, Ali Hosseingholizadeh, Ahmad Ghasemloonia
This paper presents an algorithm for the detection of single and multiple misfires in internal combustion engines, using only the signal of the knock sensor. Several experiments were conducted on a four-cylinder engine to obtain the necessary signals in the healthy and faulty conditions. The faulty conditions were created by disconnecting the wires of the spark-plugs. The signal of the knock sensor is analyzed and the time-domain signals of different orders of engine vibrations are extracted using a Vold-Kalman filter (VKF). A set of statistical features were then extracted from the time-domain signals of each order. These features are representative of the engine condition. In the next step, the computed features were plotted for different states and are analyzed. Consequently, a criterion for identifying the engine misfire is obtained based on the extracted features.
2011-05-17
Technical Paper
2011-01-1535
Christopher Edward Baker, Homer Rahnejat, Ramin Rahmani PhD, Stephanos Theodossiades
Piston compression rings are thin, incomplete circular structures which are subject to complex motions during a typical 4-stroke internal combustion engine cycle. Ring dynamics comprises its inertial motion relative to the piston, within the confine of its seating groove. There are also elastodynamic modes, such as the ring in-plane motions. A number of modes can be excited, dependent on the net applied force. The latter includes the ring tension and cylinder pressure loading, both of which act outwards on the ring and conform it to the cylinder bore. There is also the radial inward force as the result of ring-bore conjunctional pressure (i.e. contact force). Under transient conditions, the inward and outward forces do not equilibrate, resulting in the small inertial radial motion of the ring.
2011-05-17
Technical Paper
2011-01-1545
Chi La, Marco Poggi, Patrick Murphy, Ondrej Zitko
In response to environmental and fossil fuel usage concerns, the automotive industry will gradually move from Hybrid Electric Vehicles (HEV) which includes a shift of internal combustion engines toward Zero Emissions Vehicles (ZEV). Refinement is an important aspect in the successful adoption of any new technology and ZEV brings its own NVH challenges owing to the unique dynamic characteristics of the powertrain and driveline system. This paper presents considerations for addressing dynamic driveline NVH issues that are common to 100% electric vehicles; issues that manifest themselves as groans, rattles and clunks. A dynamic torsional analytical model of the powertrain & driveline will be presented. The analytical model served as the baseline for an extensive parametric study using the Genetic Algorithm (GA) technique, whereby the effectiveness of practical countermeasures was investigated.
2011-05-17
Journal Article
2011-01-1550
Wei Sun, Yinong Li, Jingying Huang
Dual Mass Flywheel (DMF) has better damping capacity than the conventional Clutch Torsional Damper (CTD), and is more suitable for diesel engine, Dual Clutch Transmission (DCT) and hybrid vehicles. Dual Mass Flywheel-Radial Spring (DMF-RS) is a DMF that has a specific structure. In the light of working principal and static analysis, the hard nonlinear torsional stiffness of DMF-RS is derived in this paper, which is very important to a driveline damper. On this basis, a simulation model is developed to analyze the dynamic response of DMF and CTD excited by idle engine; the comparison of the two dampers reveals that the DMF has better damping capacity, high-frequency filter ability and can reduce crankshaft load.
2011-05-17
Technical Paper
2011-01-1559
X. Hua, J. Liu, D. W. Herrin, T. Elnady
This paper documents a finite element approach to predict the attenuation of muffler and silencer systems that incorporate diesel particulate filters (DPF). Two finite element models were developed. The first is a micro FEM model, where a subset of channels is modeled and transmission matrices are determined in a manner consistent with prior published work by Allam and Åbom. Flow effects are considered at the inlet and outlet to the DPF as well as viscous effects in the channels themselves. The results are then used in a macro FEM model of the exhaust system where the transmission relationship from the micro-model is used to simulate the DPF. The modeling approach was validated experimentally on an example in which the plane wave cutoff frequency was exceeded in the chambers upstream and downstream to the DPF.
2011-05-17
Technical Paper
2011-01-1560
Giancarlo Chiatti, Erasmo Recco, Ornella Chiavola
The optimization of the combustion process in diesel engines is one of the challenges to improve performance, emissions, fuel consumption and NVH characteristics. This work constitutes one of the last steps of a comprehensive research program in which vibration sensors are used with the purpose of developing and setting up a methodology that is able to monitor and optimize the combustion process by means of non-intrusive measurements. Previously published results have demonstrated the direct relationship that exists between in-cylinder pressure and engine block vibration signals, as well as the sensitivity of the engine surface vibration to variation of injection parameters when the accelerometer is placed in a sensitive location of the engine block.
2011-05-17
Technical Paper
2011-01-1561
George Bailey, Douglas Fussner
Geartrain noise can be a significant contribution to the overall sound level of diesel engines. Some engine manufacturers employ isolation solutions such as sound deadening covers and foam panels to combat the problem, but these add cost. Little has been published on geartrain noise reduction, and public standards for diesel geartrain design and development are not available. This paper describes an experimental study of the relative influence of gear design parameters on the rattle noise of a diesel engine timing geartrain. The geartrains of several diesel engines were benchmarked to determine the noise reduction strategies employed. A total of three gear sets were designed and tested in a 3.3L four cylinder normally aspirated diesel engine. The experimentation quantified the influence of an anti backlash idler gear in reducing gear rattle noise, and revealed that a key path for gear rattle noise transmission is through an idler gear journal bearing shaft.
2011-04-12
Journal Article
2011-01-1386
Mark Sellnau, James Sinnamon, Kevin Hoyer, Harry Husted
A single-cylinder engine was used to study the potential of a high-efficiency combustion concept called gasoline direct-injection compression-ignition (GDCI). Low temperature combustion was achieved using multiple injections, intake boost, and moderate EGR to reduce engine-out NOx and PM emissions engine for stringent emissions standards. This combustion strategy benefits from the relatively long ignition delay and high volatility of regular unleaded gasoline fuel. Tests were conducted at 6 bar IMEP - 1500 rpm using various injection strategies with low-to-moderate injection pressure. Results showed that triple injection GDCI achieved about 8 percent greater indicated thermal efficiency and about 14 percent lower specific CO2 emissions relative to diesel baseline tests on the same engine. Heat release rates and combustion noise could be controlled with a multiple-late injection strategy for controlled fuel-air stratification. Estimated heat losses were significantly reduced.
2011-04-12
Technical Paper
2011-01-1385
Yi Ren, Xianguo Li
The importance of using biodiesel as an alternative in diesel engines has been demonstrated previously. A reduction in the soot, CO and HC emissions and an increase in the NO emission burning biodiesel fuels were reported consistently in previous technical papers. However, a widely accepted NO formation mechanism for biodiesel-fueled engines is currently lacking. As a result, in past multi-dimensional simulation studies, the NO emission of biodiesel combustion was predicted unsatisfactorily. In this study, the interaction between the soot and NO formations is considered during the prediction of the soot and NO emissions in a biodiesel-fueled engine. Meanwhile, a three-step soot model and an eight NO model which includes both the thermal NO mechanism and prompt mechanism are implemented.
2011-04-12
Technical Paper
2011-01-1389
Kihyun Kim, Sangwook Han, Choongsik Bae
Mode transition between low temperature combustion and conventional combustion was investigated in a direct injection diesel engine. Low temperature diesel combustion was realized by means of high exhaust gas recirculation rate (69~73%) and early injection timing (-28~ -16 crank angle degree after top dead center) compared with those (20% exhaust gas recirculation rate and -8 crank angle degree after top dead center) of conventional combustion. Tests were carried out at different engine speeds and injection pressures. Exhaust gas recirculation rate was changed transiently by controlling each throttle angle for fresh air and exhaust gas recirculation to implement mode transition. Various durations for throttle transition were applied to investigate the effect of speed change of exhaust gas recirculation rate on the characteristics of mode transition.
2011-04-12
Technical Paper
2011-01-1388
Andrew Smallbone, Amit Bhave, Aaron R. Coble, Sebastian Mosbach, Markus Kraft, Robert McDavid
In recent decades, “physics-based” gas-dynamics simulation tools have been employed to reduce development timescales of IC engines by enabling engineers to carry out parametric examinations and optimisation of alternative engine geometry and operating strategy configurations using desktop PCs. However to date, these models have proved inadequate for optimisation of in-cylinder combustion and emissions characteristics thus extending development timescales through additional experimental development efforts. This research paper describes how a Stochastic Reactor Model (SRM) with reduced chemistry can be employed to successfully determine in-cylinder pressure, heat release and emissions trends from a diesel fuelled engine operated in compression ignition direct injection mode using computations which are completed in 147 seconds per cycle.
2011-04-12
Technical Paper
2011-01-1382
Wenbin Yu, Bin Liu, Yang Li, Qingpeng Su, Yiqiang Pei, Wanhua Su
Combustion control strategy for high efficiency and low emissions in a heavy duty (H D) diesel engine was investigated experimentally in a single cylinder test engine with a common rail fuel system, EGR (Exhaust Gas Recirculation) system, boost system and retarded intake valve closing timing actuator. For the operation loads of IMEPg (Gross Indicated Mean Effective Pressure) less than 1.1 MPa the low temperature combustion (LTC) with high rate of EGR was applied. The fuel injection modes of either single injection or multi-pulse injections, boost pressure and retarded intake valve closing timing (RIVCT) were also coupled with the engine operation condition loads for high efficiency and low emissions. A higher boost pressure played an important role in improving fuel efficiency and obtaining ultra-low soot and NOx emissions.
2011-04-12
Journal Article
2011-01-1381
Ezio Mancaruso, Luigi Sequino, Bianca Maria Vaglieco, Claudio Ciaravino, Alberto Vassallo
The present paper describes the results of a cooperative research project between GM Powertrain Europe and Istituto Motori - CNR aimed at studying the impact of both fresh and highly oxidized RME at two levels of blending on spray formation and combustion in modern automotive diesel engines. The tests were performed on an optical single-cylinder engine sharing combustion system configuration with the 2.0L Euro5 GM diesel engine for passenger car application. Two blends (B50 and B100) blending were tested for both fresh and aged RME and compared with commercial diesel fuel in two different operating points typical of NEDC (1500rpm/2bar BMEP and 2000rpm/5bar BMEP). The experimental activity was devoted to an in-depth investigation of the spray density, breakup and penetration, mixture formation, combustion and soot formation, by means of optical techniques.
2011-04-12
Journal Article
2011-01-1384
Michael J. Tess, Chang-Wook Lee, Rolf D. Reitz
Several diffusion combustion scaling models were experimentally tested in two geometrically similar single-cylinder diesel engines with a bore diameter ratio of 1.7. Assuming that the engines have the same in-cylinder thermodynamic conditions and equivalence ratio, the combustion models primarily change the fuel injection pressure and engine speed in order to attain similar performance and emissions. The models tested include an extended scaling model, which scales diffusion flame lift-off length and jet spray penetration; a simple scaling model, which only scales spray penetration at equal mean piston speed; and a same speed scaling model, which holds crankshaft rotational velocity constant while also scaling spray penetration. Successfully scaling diffusion combustion proved difficult to accomplish because of apparent differences that remained in the fuel-air mixing and heat transfer processes.
2011-04-12
Journal Article
2011-01-1383
Clément Chartier, Oivind Andersson, Bengt Johansson, Mark Musculus, Mohan Bobba
Post-injection strategies aimed at reducing engine-out emissions of unburned hydrocarbons (UHC) were investigated in an optical heavy-duty diesel engine operating at a low-load, low-temperature combustion (LTC) condition with high dilution (12.7% intake oxygen) where UHC emissions are problematic. Exhaust gas measurements showed that a carefully selected post injection reduced engine-out load-specific UHC emissions by 20% compared to operation with a single injection in the same load range. High-speed in-cylinder chemiluminescence imaging revealed that without a post injection, most of the chemiluminescence emission occurs close to the bowl wall, with no significant chemiluminescence signal within 27 mm of the injector. Previous studies have shown that over-leaning in this near-injector region after the end of injection causes the local equivalence ratio to fall below the ignitability limit.
2011-04-12
Technical Paper
2011-01-1395
Cody William Squibb, Harold Schock, Thomas Stuecken, Mulyanto Poort, Kyle Crayne, Charles Gray, Fakhri Hamady
This work presents a method for simultaneously capturing visible and infrared images along with pressure data in an optical Diesel engine based on the International 4.5L VT275 engine. This paper seeks to illustrate the merits of each imaging technique for visualizing both in-cylinder fuel spray and combustion. The engine was operated under a part load, high simulated exhaust gas recirculation operating condition. Experiments examining fuel spray were conducted in nitrogen. Overlays of simultaneously acquired infrared and visible images are presented to illustrate the differences in imaging between the two techniques. It is seen that the infrared images spatially describe the fuel spray, especially fuel vapors, and the fuel mixing process better than the high-speed visible images.
2011-04-12
Technical Paper
2011-01-1394
Carl Magnus Lewander, Bengt Johansson, Per Tunestal
Partially Premixed Combustion (PPC) is a combustion concept by which it is possible to get low smoke and NOx emissions simultaneously. PPC requires high EGR levels to extend the ignition delay so that air and fuel mix prior to combustion to a larger extent than with conventional diesel combustion. This paper investigates the operating region of single injection PPC for three different fuels; Diesel, low octane gasoline with similar characteristics as diesel and higher octane standard gasoline. Limits in emissions are defined and the highest load that fulfills these requirements is determined. The investigation shows the benefits of using high octane number fuel for Multi-Cylinder PPC. With high octane fuel the ignition delay is made longer and the operating region of single injection PPC can be extended significantly. Experiments are carried out on a multi-cylinder heavy-duty engine at low, medium and high speed.
2011-04-12
Technical Paper
2011-01-1397
Vladimir Marcov, Sergey Gladyshev, Sergey Devianin
Parameters of the fuel economy and the exhaust gases pollution of the high-speed diesel engines, with unshared and half-shared combustion chambers, are predetermined by processes of fuel spray and fuel-air mixture creation. The parameters of these processes (fuel spraying and development of flame structure dynamic) appreciably depend from design features of a flowing part of the injector tips. The major parameters of the injector tips design are the spraying nozzles length and the ratio of the length these nozzles to their diameters. The experimental research of the D-245.12C type diesel engine has been carried out. Fuel injectors of the diesel engine were equipped with injector tips of different spray nozzles lengths. The experimental data show improvement fuel efficiency, reduction of emissions and smoke due to optimization of geometries in the injector tip.
Viewing 1 to 30 of 42298

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