Optical Investigations of an Oxygenated Alternative Fuel in a Single Cylinder DISI Light Vehicle Gasoline Engine

A novel first principle based control oriented model of a gasoline engine is proposed which also carries diagnostic capabilities. Unlike existing control oriented models, the formulated model reflects dynamics of the faultless as well as faulty engine with high fidelity. In the proposed model, the torque production subsystem is obtained by integration of further two subsystems that is model of a single cylinder torque producing mechanism and an analytical gasoline engine cylinder pressure model. Model of a single cylinder torque producing mechanism is derived using constrained equation of motion (EOM) in Lagrangian mechanics. While cylinder pressure is evaluated using a closed form parametric analytical gasoline engine cylinder pressure model. Novel attributes of the proposed model include minimal usage of empirical relations and relatively wider region of model validity. Additionally, the model provides model based description of crankshaft angular speed fluctuations and tension in the rigid bodies. Capacity of the model to describe the system dynamics under fault conditions is elaborated with case study of an intermittent misfire condition. Model attains new capabilities based on the said novel attributes. The model is successfully validated against experimental data.

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Comparative assessment of engine vibration, combustion, performance and emission characteristics between single and twin-cylinder diesel engines in unifuel and dual-fuel mode

Journal of Energy Resources Technology ◽

10.1115/1.4052998 ◽

2021 ◽

pp. 1-39

Author(s):

Akash Chandrabhan Chandekar ◽

Sushmita Deka ◽

Biplab K. Debnath ◽

Ramesh Babu Pallekonda

Keyword(s):

Natural Gas ◽

Alternative Fuels ◽

Load Condition ◽

Alternative Fuel ◽

Dual Fuel ◽

Cylinder Pressure ◽

Compressed Natural Gas ◽

Single Cylinder ◽

Engine Vibration ◽

Single Cylinder Engine

Abstract The persistent efforts among the researchers are being done to reduce emissions by the exploration of different alternative fuels. The application of alternative fuel is also found to influence engine vibration. The present study explores the potential connection between the change of the engine operating parameters and the engine vibration pattern. The objective is to analyse the effect of alternative fuel on engine vibration and performance. The experiments are performed on two different engines of single cylinder and twin-cylinder variants at the load range of 0 to 34Nm, with steps of 6.8Nm and at the constant speed of 1500rpm. The single cylinder engine, fuelled with only diesel mode, is tested at two compression ratios of 16.5 and 17.5. While, the twin-cylinder engine with a constant compression ratio of 16.5, is tested at both diesel unifuel and diesel-compressed natural gas dual-fuel modes. Further, in dual-fuel mode, tests are conducted with compressed natural gas substitutions of 40%, 60% and 80% for given loads and speed. The engine vibration signatures are measured in terms of root mean square acceleration, representing the amplitude of vibration. The combustion parameters considered are cylinder pressure, rate of pressure rise, heat release rate and ignition delay. At higher loads, the vibration amplitude increases along with the cylinder pressure. The maximum peak cylinder pressure of 95bar is found in the case of the single cylinder engine at the highest load condition that also produced a peak vibration of 3219m/s2.

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Sound & vibration control for a single-cylinder gasoline engine based on parameter optimization of timing-chain system

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407017744426 ◽

2017 ◽

Vol 232 (13) ◽

pp. 1815-1827

Author(s):

Xianjun Hou ◽

Songze Du ◽

Chihua Lu ◽

Zien Liu ◽

Hao Zheng ◽

...

Keyword(s):

Optimization Design ◽

Gasoline Engine ◽

Subjective Evaluation ◽

Dynamic Performance ◽

Transverse Displacement ◽

Single Cylinder ◽

Chain System ◽

Design Scheme ◽

Single Cylinder Engine ◽

Timing System

In order to promote the idling noise quality of a single-cylinder gasoline engine, this paper addresses sound source identification and noise control research. The noise was identified by the application of subjective evaluation, acoustic spectrum and sound intensity analysis. It was found that the noise was caused by the anomalous dynamic performance of the timing system under idling conditions. Furthermore, sound and vibration characteristics of timing system were improved by design methodology research of key components. A multi-body dynamic model was established to characterize dynamic characteristics of the timing system under idling conditions. The key factor of producing noise was that the fluctuation of contact force between the chain and guide and transverse displacement of the chain were much higher than those of the allowable design limit. For the lowest design alternation and manufacturing costs, the work analyzed six timing system improvement schemes obtained by cross combination of tensioner blade line and guide strip radian parameters. After that, the optimal design scheme which could improve dynamic performance parameters of the timing system was derived. The design scheme was conducted with a acoustic test of engine to derive the following results. The noise level of a single-cylinder engine under idling conditions decreased by 3 dB(A). The abnormal noise of the original engine was eliminated under subjective evaluation. The sound quality under other working conditions had no apparent deterioration. Research shows that guide and tensioner blade line optimization design could improve dynamic performance of the timing chain system to eliminate abnormal noise, thereby significantly improving the acoustic characteristic of a single-cylinder engine.

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