Noise, Emissions and Fuel Economy Investigation on a Small DI Diesel Engine Working on Jatropha Bio-Diesel, Using Taguchi Methods

Author(s):  
Vineet Kumar ◽  
Rakesh Parkash Gakkhar

Experimental investigation was carried out in order to optimize the performance of a small high speed direct injection diesel engine running on Jatropha methyl ester (JME), using Taguchi methods. In the investigation three controlled parameters — injection timing, load and speed — were varied at three levels and their effect on the engine output responses — engine noise, combustion noise, smoke, NOx, HC emissions and brake specific fuel consumption were studied. Taguchi method was found to be efficient for investigating the effect of speed, load and injection timing on the engine noise, emissions and fuel economy. Analysis of variance (ANOVA) was used to find out the percentage contributions of the controlled parameters on the engine output responses. To optimize the performance, optimum combinations of the controlled parameters were found using the signal to noise (S/N) ratio. The engine output responses were predicted at those combinations. Further, confirmation runs were carried out which showed good agreement with the predicted engine output responses.

Author(s):  
Z Win ◽  
R P Gakkhar ◽  
S C Jain ◽  
M Bhattacharya

In order to optimize the performance of a small direct injection (DI) diesel engine with respect to noise, emissions, and fuel economy, an experimental investigation was undertaken using Taguchi methods. A single-cylinder 3.5 kW diesel engine was selected for performance tests at different levels of two operating parameters (speed and load) and six injection parameters of the engine (static injection timing, plunger diameter, nozzle valve opening pressure, nozzle hole diameter, number of nozzle holes, and nozzle tip protrusion). These controlled parameters were varied at two levels, and the resulting changes in responses were investigated, namely engine noise, combustion noise, smoke, brake specific fuel consumption (b.s.f.c.), and emissions of unburned hydrocarbons (HC), oxides of nitrogen (NO x), and carbon monoxide (CO) were investigated. The optimum values of engine noise, combustion noise, smoke, emissions, and b.s.f.c. could be predicted using signal-noise ( S/N) ratios, and a relevant combination of controlled input parameters was specified. Results of confirmation runs of the engine showed good agreement with the predicted quantities of interest based on Taguchi analysis. The relative importance of the controlled parameters to the above responses was evaluated in terms of the percentage contributions of the parameters using analysis of variance (ANOVA). The Taguchi method of experimental design was found to be robust and more cost effective for understanding the relationship between diesel engine parameters and noise, emissions, and b.s.f.c. than full factorial design.


Author(s):  
Raouf Mobasheri ◽  
Zhijun Peng

High-Speed Direct Injection (HSDI) diesel engines are increasingly used in automotive applications due to superior fuel economy. An advanced CFD simulation has been carried out to analyze the effect of injection timing on combustion process and emission characteristics in a four valves 2.0L Ford diesel engine. The calculation was performed from intake valve closing (IVC) to exhaust valve opening (EVO) at constant speed of 1600 rpm. Since the work was concentrated on the spray injection, mixture formation and combustion process, only a 60° sector mesh was employed for the calculations. For combustion modeling, an improved version of the Coherent Flame Model (ECFM-3Z) has been applied accompanied with advanced models for emission modeling. The results of simulation were compared against experimental data. Good agreement of calculated and measured in-cylinder pressure trace and pollutant formation trends were observed for all investigated operating points. In addition, the results showed that the current CFD model can be applied as a beneficial tool for analyzing the parameters of the diesel combustion under HSDI operating condition.


Author(s):  
I P Gilbert ◽  
A R Heath ◽  
I D Johnstone

The need to increase power, to improve fuel economy and to meet stringent exhaust emissions legislation with a high level of refinement has provided a challenge for the design of a compact high-speed direct injection (HSDI) diesel engine. This paper describes various aspects of cylinder head design with particular consideration of layout and number of valves, valve actuation, port selection strategy, fuel injection systems and cylinder head construction.


Author(s):  
Amy M. Peterson ◽  
Po-I Lee ◽  
Ming-Chia Lai ◽  
Ming-Cheng Wu ◽  
Craig L. DiMaggio

This paper compares 20% bio-diesel (B20-choice white grease) fuel with baseline ultra low sulfur diesel (ULSD) fuel on the performance of combustion and emissions of a light-duty 4-cylinder 2.8-liter common-rail DI diesel engine. The results show that operating the engine in the Low Temperature Combustion (LTC) regime produces lower PM and NOx with a slight penalty in fuel consumption, THC, and CO emissions. B20, in general, produces less soot. A slight increase in NOx emissions is shown with B20 compared to ULSD, with an exception at the high speed point where B20 has lower NOx values. In addition, the performance and emission characteristics are investigated as a function of the ECU injection strategy. The addition of pilot injections is found to effectively reduce combustion noise and extends the injection retard window to reach LTC combustion regimes with acceptable noise level for LD diesel engines.


1987 ◽  
Vol 109 (2) ◽  
pp. 187-192 ◽  
Author(s):  
A. C. Alkidas

The factors influencing premixed burning and the importance of premixed burning on the exhaust emissions from a small high-speed direct-injection diesel engine were investigated. The characteristics of premixed and diffusion burning were examined using a single-zone heat-release analysis. The mass of fuel burned in premixed combustion was found to be linearly related to the product of engine speed and ignition-delay time and to be essentially independent of the total amount of fuel injected. Accordingly, the premixed-burned fraction increased with increasing engine speed, with decreasing fuel-air ratio and with retarding injection timing. The hydrocarbon emissions did not correlate well with the premixed-burned fraction. In contrast, the oxides of nitrogen emissions were found to increase with decreasing premixed-burned fraction, indicating that diffusion burning, and not premixed burning, is the primary source of oxides of nitrogen emissions.


Author(s):  
Wang Hewu ◽  
Zhou Longbao

A quantity of 10 per cent dimethyl ether (DME) was added to diesel fuel, and an investigation of the performance of a direct injection (DI) diesel engine fuelled with blend fuel was carried out. The test results showed that, in comparison with diesel operation, the torque at low engine speed was increased; the brake specific fuel consumption (b.s.f.c.) with speed characteristics at full load was reduced by 20 g/kW h on average; the smoke was reduced significantly, and the coeffcient of light absorption of smoke decreased by 50 per cent; the NOx and HC emissions were also clearly reduced, and the CO emission was at the same level as that of a diesel engine.


Author(s):  
T-G Fang ◽  
R E Coverdill ◽  
C-F F Lee ◽  
R A White

An optically accessible high-speed direct-injection diesel engine was used to study the effects of injection angles on low-sooting combustion. A digital high-speed camera was employed to capture the entire cycle combustion and spray evolution processes under seven operating conditions including post-top-dead centre (TDC) injection and pre-TDC injection strategies. The nitrogen oxide (NO x) emissions were also measured in the exhaust pipe. In-cylinder pressure data and heat release rate calculations were conducted. All the cases show premixed combustion features. For post-TDC injection cases, a large amount of fuel deposition is seen for a narrower-injection-angle tip, i.e. the 70° tip, and ignition is observed near the injector tip in the centre of the bowl, while for a wider-injection-angle tip, namely a 110° tip, ignition occurs near the spray tip in the vicinity of the bowl wall. The combustion flame is near the bowl wall and at the central region of the bowl for the 70° tip. However, the flame is more distributed and centralized for the 110° tip. Longer spray penetration is found for the pre-TDC injection timing cases. Liquid fuel impinges on the bowl wall or on the piston top and a fuel film is formed. Ignition for all the pre-TDC injection cases occur in a distributed way in the piston bowl. Two different combustion modes are observed for the pre-TDC injection cases including a homogeneous bulky combustion flame at earlier crank angles and a heterogeneous film combustion mode with luminous sooting flame at later crank angles. In terms of soot emissions, NO x emissions, and fuel efficiency, results show that the late post-TDC injection strategy gives the best performance.


2004 ◽  
Vol 126 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Renshan Liu ◽  
Chao Zhang

A numerical study of NOx reduction for a Direct Injection (DI) Diesel engine with complex geometry, which includes intake/exhaust ports and moving valves, was carried out using the commercial computational fluid dynamics software KIVA-3v. The numerical simulations were conducted to investigate the effects of engine operating and geometrical parameters, including fuel injection timing, fuel injection duration, and piston bowl depth, on the NOx formation and the thermal efficiency of the DI Diesel engine. The tradeoff relationships between the reduction in NOx and the decrease in thermal efficiency were established.


Author(s):  
Sukhbir Singh Khaira ◽  
Amandeep Singh ◽  
Marcis Jansons

Acoustic noise emitted by a diesel engine generally exceeds that produced by its spark-ignited equivalent and may hinder the acceptance of this more efficient engine type in the passenger car market (1). This work characterizes the combustion noise from a single-cylinder direct-injection diesel engine and examines the degree to which it may be minimized by optimal choice of injection parameters. The relative contribution of motoring, combustion and resonance components to overall engine noise are determined by decomposition of in-cylinder pressure traces over a range of load, injection pressure and start of injection. The frequency spectra of microphone signals recorded external to the engine are correlated with those of in-cylinder pressure traces. Short Time Fourier Transformation (STFT) is applied to cylinder pressure traces to reveal the occurrence of motoring, combustion noise and resonance in the frequency domain over the course of the engine cycle. Loudness is found to increase with enhanced resonance, in proportion to the rate of cylinder pressure rise and under conditions of high injection pressure, load and advanced injection timing.


1999 ◽  
Vol 123 (1) ◽  
pp. 167-174 ◽  
Author(s):  
P. J. Tennison ◽  
R. Reitz

An investigation of the effect of injection parameters on emissions and performance in an automotive diesel engine was conducted. A high-pressure common-rail injection system was used with a dual-guided valve covered orifice nozzle tip. The engine was a four-valve single cylinder high-speed direct-injection diesel engine with a displacement of approximately 12 liter and simulated turbocharging. The engine experiments were conducted at full load and 1004 and 1757 rev/min, and the effects of injection pressure, multiple injections (single vs pilot with main), and pilot injection timing on emissions and performance were studied. Increasing the injection pressure from 600 to 800 bar reduced the smoke emissions by over 50 percent at retarded injection timings with no penalty in oxides of nitrogen NOx or brake specific fuel consumption (BSFC). Pilot injection cases exhibited slightly higher smoke levels than single injection cases but had similar NOx levels, while the single injection cases exhibited slightly better BSFC. The start-of-injection (SOI) of the pilot was varied while holding the main SOI constant and the effect on emissions was found to be small compared to changes resulting from varying the main injection timing. Interestingly, the point of autoignition of the pilot was found to occur at a nearly constant crank angle regardless of pilot injection timing (for early injection timings) indicating that the ignition delay of the pilot is a chemical delay and not a physical (mixing) one. As the pilot timing was advanced the mixture became overmixed, and an increase of over 50 percent in the unburned hydrocarbon emissions was observed at the most advanced pilot injection timing.


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