GM Diesel Research Articles

Sources of Noise Pollution in Mashhad Railway Station

Background: Exposure to noise is an important safety and health problem in many industries. The rail transport industry is one of the industries involved with this problem due to the variety of equipment and its scope. The present study aimed to evaluate noise pollution and determine the sources of noise at Mashhad railway station. Methods: In this descriptive-analytic study in 2014, the departments with noise pollution were identified and studied based on an initial assessment of all parts of the railway station. Noise was measured in ten departments and units. The environmental and local noise was measured by calibrated sound level meter Model CEL485 in A and C networks according to ISO9612 and ISO 11200 standards. Then the collected data entered and analyzed in Surfer V.10 and Excel software. Results: The results of noise measurement showed that the average sound pressure level in units of Diesel GM, repair shop, refueling station, Diesel Siemens, and platform 3 was in hazard range. The results of measurement of the average sound pressure level in departments and units and the isosonic mappings drawn by Surfer V.10 software as well as the results of the average noise level in GM diesel showed that GM diesel (with LP=87.60 dB (A)) is the main source of noise at Mashhad railway station. The results of this study showed that diesel engines, gearboxes, moving trains, and beeps are the main noise generator components in GM diesel. The highest mean sound pressure level among these components was related to the diesel engine with an average sound pressure level of 87.60 dB (A). In general, the average sound pressure level of this diesel was 95.45 dB in the dominant frequency of 63 Hz. Conclusion: Based on the result of this study, GM diesel plays a major role in transporting at Mashhad railway station, accordingly the design and implementation of technical control measures such as chamber and enclosure of noise generator components are essential to reduce the average sound pressure level.

Development and Assessment of a Fast Calibration Tool for Zero-dimensional Combustion Models in DI Diesel Engines

Abstract A fast calibration tool for the tuning of zero-dimensional combustion models has been developed and assessed on a 1.6 L Euro 6 GM diesel engine. The tool is capable of identifying the optimal set of model tuning parameters on the basis of a few combustion metrics related to heat release, as well as of peak firing pressure and indicated mean effective pressure. The method has been assessed and validated for a real-time zero dimensional combustion model previously developed by the authors. A detailed comparison has been made between the conventional and the newly proposed calibration procedures, at both steady-state and transient-state conditions.

Comparison of performance and emission characteristics of diesel and diesel-water blend under varying injection timings

The present work is focused on comparison of diesel and diesel-water blend on emissions and performance parameters of the diesel engine. The emission parameters such as NO, CO and soot are investigated numerically by using commercially available CFD software AVL FIRE. In addition to that, performance parameters in terms of thermal efficiency, indicated power, torque and brake specific fuel consumption is also analyzed numerically. For better understanding of the software, two validations are provided in the present study. In first validation, the commercial code is validated by experimental data available in the literature; and it is found to be satisfactory in terms of pressure and temperature. Whereas, second validation is taken out with model-TV1 of Kirloskar single cylinder diesel engine and results of pressure and heat release rate are acceptable. Numerical simulation is conducted on a four-cylinder, 1.9L GM diesel engine with piston having a rectangular cavity. The blend is prepared by using 95% diesel and 5% water and compared with diesel fuel. As a part of the above study, injection timing is varied as 6°, 10° and 14° BTDC for diesel as well as diesel-water blend. The result shows that, diesel-water blend reduces emission without affecting the engine performance parameters, when engine fueled with diesel alone. Nevertheless, at an injection angle of 6° BTDC, diesel-water blend with 5% by mass is seems to be an effective substitute in diesel engines in terms of engine emissions and operation parameters. Keywords: Diesel engine, combustion modeling, diesel-water blends, NO, CO and soot emission, efficiency and power

Development and Validation of a Real-Time Model for the Simulation of the Heat Release Rate, In-Cylinder Pressure and Pollutant Emissions in Diesel Engines

A real-time mean-value engine model for the simulation of the HRR (heat release rate), in-cylinder pressure, brake torque and pollutant emissions, including NOx and soot, has been developed, calibrated and assessed at both and transient conditions for a Euro 6 1.6L GM diesel engine. The chemical energy release has been simulated using an improved version of a previously developed model that is based on the accumulated fuel mass approach. The in-cylinder pressure has been evaluated on the basis of the inversion of a single-zone model, using the net energy release as input. The latter quantity was derived starting from the simulated chemical energy release, and evaluating the heat transfer of the charge with the walls. NOx and soot emissions were simulated on the basis of semiempirical correlations that take into account the in-cylinder thermodynamic properties, the chemical energy release and the main engine parameters. The model is also referred to as steady-state as the main thermodynamic properties in the intake and exhaust manifolds, as well as the inducted mass flow rate, have been evaluated by means of cor relations that were calibrated under conditions. This has allowed a very low computational time to be obtained, so that the approach is suitable for implementation in an ECU for real-time applications. The model has been calibrated over several experimental tests carried out at a dynamic test bench at GMPT-E (General Motors powertrain-Europe). The tests include a complete engine map as well as several full-factorial variation lists of the main engine parameters, which have been conducted for seven representative operating conditions of the NEDC (New European Driving Cycle). The validation has been carried out under transient conditions over NEDC and WLTP missions, which were simulated at the dynamic test bench for a C-class vehicle.

Spray and Soot Formation Analysis by Means of a Quasi-Dimensional Multizone Model in a Single Cylinder Diesel Engine under Euro 4 Operating Conditions

An investigation has been carried out on the spray penetration and soot formation processes in a research diesel engine by means of a quasi-dimensional multizone combustion model. The model integrates a predictive non stationary 1D spray model developed by the Sandia National Laboratory, with a diagnostic multizone thermodynamic model, and is capable of predicting the spray formation, combustion and soot formation processes in the combustion chamber. The multizone model was used to analyze three operating conditions, i.e., a zero load point (BMEP = 0 bar at 1000 rpm), a medium load point (BMEP = 5 bar at 2000 rpm) and a medium-high load point (BMEP = 10 bar at 2000 rpm). These conditions were experimentally tested in an optical single cylinder engine with the combustion system configuration of a 2.0L Euro4 GM diesel engine for passenger car applications. The experimental spray tip penetration and spreading angle were evaluated on the basis of images acquired by means of a high-speed CCD camera, while the experimental trend of the in-cylinder soot concentration was derived by means of the two-color pyrometry method. The acquired experimental data have allowed useful information to be obtained for the assessment of the multizone model. Well-defined trends between some of the model parameters and the engine operating conditions (namely, speed and load) have been found and preliminary correlations have been developed

Assessment of a New Quasi-Dimensional Multizone Combustion Model for the Spray and Soot Formation Analysis in an Optical Single Cylinder Diesel Engine

An innovative quasi-dimensional multizone combustion model for the spray formation, combustion and emission formation analysis in DI diesel engines was assessed and applied to an optical single cylinder engine. The model, which has been recently presented by the authors, integrates a predictive non stationary 1D spray model developed by the Sandia National Laboratory, with a diagnostic multizone thermodynamic model. The 1D spray model is capable of predicting the equivalence ratio of the fuel during the mixing process, as well as the spray penetration. The multizone approach is based on the application of the mass and energy conservation laws to several homogeneous zones identified in the combustion chamber. A specific submodel is also implemented to simulate the dilution of the burned gases. Soot formation is modeled by an expression which derives from Kitamura et al.'s results, in which an explicit dependence on the local equivalence ratio is considered. The model was used to analyze low load (BMEP = 2 bar at 1500 rpm) and medium load (BMEP = 5 bar at 2000 rpm) operating conditions in an optical single cylinder engine sharing the combustion system configuration of the 2.0L Euro5 GM diesel engine for passenger car application.

The Key Role of the Closed-loop Combustion Control for Exploiting the Potential of Biodiesel in a Modern Diesel Engine for Passenger Car Applications

The present paper describes the results of a cooperative research project between GM Powertrain Europe and Istituto Motori CNR aimed at studying the capability of GM Combustion Closed-Loop Control (CLCC) in enabling seamless operation with high biodiesel blending levels in a modern diesel engine for passenger car applications. As a matter of fact, fuelling modern electronically-controlled diesel engines with high blends of biodiesel leads to a performance reduction of about 12-15% at rated power and up to 30% in the low-end torque, while increasing significantly the engine-out NOx emissions. These effects are both due to the interaction of the biodiesel properties with the control logic of the electronic control unit, which is calibrated for diesel operation. However, as the authors previously demonstrated, if engine calibration is re-tuned for biodiesel fuelling, the above mentioned drawbacks can be compensated and the biodiesel environmental inner qualities can be fully deployed. In order to enable such calibration re-tuning, it is fundamental to achieve a reliable biodiesel blending detection, and to use it for realtime combustion optimization, chiefly by optimizing the injection train. Therefore, the authors investigated the capability of CLCC to detect biodiesel blending ratio on the recently released 2.0L Euro5 GM diesel engine equipped with embedded pressure sensors in the glow plugs. Various blends of biodiesel were tested, notably 20% by volume (B20), 50% (B50) and pure biodiesel (B100). Tests on the multicylinder engine were carried out in a wide range of engine operating points for the complete characterization of the biodiesel performance in the NEDC cycle. The results demonstrated the successful capability of the CLCC control to detect biodiesel blending with reasonable accuracy and to implement the corrective actions to avoid emission drift and performance losses.

Conspiracy or Consumer Choice?

Conspiracy or Consumer Choice? Gregory Thompson (bio) David W. Jones, Mass Motorization, Mass Transit: An American History and Policy Analysis In this sweeping history of urban transportation modernization and postmodernization in the United States (Bloomington: Indiana University Press, 2008, pp. 268, $39.95), David Jones debunks popular explanations for the decline of mass transit and the rise of mass motorization. In their place he resurrects an earlier explanation based on rising income and personal choice. Unlike other proponents of the personal choice explanation, however, Jones is alarmed about its consequences, including foreign oil dependence, global warming, and ever-worsening congestion. One of his more interesting chapters accounts for the collapse of the domestic automobile industry despite the public’s overwhelming endorsement of automobility. He concludes with prescriptions for dealing with the negative consequences of mass mobility that are consistent with the public’s enthusiasm for it. There are two schools of thought on the decline of mass transit and the rise of mass motorization in the United States. The first developed in the 1960s, when economic historian John Meyer, economist John Kain, and several followers explained these phenomena in terms of rising personal incomes. More income provided middle-class Americans more choices for travel and places to live, and middle-class Americans overwhelmingly chose to buy cars and live in large, single-family homes in the suburbs. Such choices greatly stimulated traffic growth, to which federal and state governments responded into the 1970s by building highways thought to have sufficient capacity to alleviate congestion. The second school coalesced in the early 1970s, when Bradford Snell, counsel to the U.S. Senate Subcommittee on Antitrust and Monopoly, argued a counterthesis that some scholars embraced and that was popularized by a Hollywood movie, Who Framed Roger Rabbit, and a public television [End Page 673] documentary, Taken for a Ride. Snell and his followers blamed the demise of mass transit and the subsequent mass motorization of American society on corporate and government manipulation of transportation supply in contravention of middle-class American demands. They told how General Motors and other auto interests had set up holding companies that bought up viable street-railway systems throughout the nation and replaced them with GM diesel buses whose service was so inferior to that of streetcars that Americans turned to private automobiles and stopped using mass transit. Federal and state highway policy sought to enhance demand for autos with a massive interstate highway system and urban freeways that ultimately lured Americans and their jobs out of the cities and to the distant suburbs where mass-transit service could not possibly be provided. According to this view, one has only to look to Canada and to western Europe to see where different government policies toward highways and mass transit have resulted in different and more socially benign cities and travel behavior. Jones’s historical narrative speaks to the two theses, though with insufficient credit to their originators, as it weaves together relationships among various statistics from the United States, Canada, and several European countries over the span of roughly thirteen decades. These statistics include real per-capita income, transit investments, transit ridership, transit profitability, automobile ownership, annual vehicle miles, and auto industry output and profitability, among others. Informed by a limited number of interviews with government transportation specialists, Jones compares trends indicated by these statistics. He also sets the trends against transportation policies of the various countries while commenting on the plausibility of the two explanations. Numerous points that generally refute the Snell thesis and affirm the Meyer thesis emerge from the narrative. For example, the streetcar industry went into the red during World War I, two decades before automotive interests began purchasing operating companies. When automotive interests did show interest in streetcars, there were no competing interests against which they had to bid, because streetcars had become hopelessly unprofitable. Even during the prosperous 1920s streetcar patronage fell in all but the largest U.S. cities as auto ownership soared. At the same time, beginning with adoption of the income tax and the simultaneous exemption of interest on home mortgages in 1913, auto-oriented suburbs grew at an astounding rate. Jones makes a convincing argument that consumer...

GM diesel complaints may go to BBB arbitration

GM diesel complaints may go to BBB arbitration