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Avinash Kumar Agarwal

Bio: Avinash Kumar Agarwal is an academic researcher from Indian Institute of Technology Kanpur. The author has contributed to research in topic(s): Diesel fuel & Combustion. The author has an hindex of 53, co-authored 422 publication(s) receiving 14279 citation(s). Previous affiliations of Avinash Kumar Agarwal include University of Wisconsin-Madison & Indian Institutes of Technology.
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Journal ArticleDOI
Nikhil Sharma1, Avinash Kumar Agarwal1Institutions (1)
Abstract: Optimized fuel injection timings in internal combustion engines exhibit superior performance, combustion characteristics, and lower emissions. Particularly, particulate emissions from a gasoline direct injection (GDI) engines are highly dependent on fuel injection timings. GDI engines have emerged as a popular choice of power plants for automobiles among customers worldwide. They are preferred over multiple-port fuel injection (MPFI) engines in the transport sector because of their superior fuel economy and performance characteristics. The main objective of this study is to optimize a GDI engine for the lowest particulate emission at different fuel injection timings. GDI engine was investigated for particulate matter (PM) mass/particulate number (PN) emissions at five fuel injection timings (230, 250, 270, 290, and 310 deg bTDC), covering the entire envelope. Once the optimum fuel injection timing was determined, an engine exhaust particle sizer was used to measure the particle size-number distribution. Particulate samples from the engine were also collected on a filter paper for morphological investigations of particulates collected under optimized fuel injection timings. These experiments confirmed the importance and need to optimize the fuel injection timings at every engine operating point to reduce the PM/PN emissions from a GDI engine, which remains one of the biggest unresolved challenges to this technology.

1 citations

Journal ArticleDOI
Abstract: Researchers have investigated reactivity-controlled compression ignition (RCCI) combustion in the past several years because of its excellent combustion, performance, and emission features. In this experimental study, the RCCI combustion strategy was investigated using mineral diesel/butanol fuel-pair at various premixed ratios (rp) on an energy basis (rp = 0.25, 0.50, and 0.75) at varying engine loads (BMEP = 1, 2, 3, and 4 bars) vis-à-vis baseline compression ignition (CI) combustion (rp = 0.0) strategy. Experiments were performed at constant engine speed (1500 rpm) in a single-cylinder research engine equipped with state-of-the-art features. The outcome of the investigation showed that port injection of Butanol as low reactivity fuel (LRF) improved the combustion and yielded superior engine performance than baseline CI combustion strategy. Engine exhaust emissions exhibited significantly lower nitrogen (NOx) oxides with butanol RCCI combustion strategy than baseline CI combustion strategy. Increasing rp of butanol showed improved combustion and emission characteristics; however, performance characteristics were not affected significantly. Particulate characteristics of the RCCI combustion strategy also showed a significant reduction in particle number concentration than baseline CI combustion. Slightly different combustion, performance, and emission characteristics of mineral diesel/ butanol-fueled RCCI combustion strategy compared to other test fuels such as mineral diesel/methanol, and mineral diesel/ethanol-fueled RCCI combustion strategy was an interesting observation of this study. Overall, this study indicated that butanol could be used as LRF in RCCI combustion engines to achieve superior combustion and emission characteristics.

2 citations

Journal ArticleDOI
Abstract: In situ spatial soot and temperature distributions were investigated experimentally for B20 (20% v/v butanol and balance mineral diesel blend) vis-a-vis mineral diesel using endoscopic visualization technique. Endoscope captured the in-cylinder combustion images in a production-grade direct injection compression ignition (DICI) engine at varying engine operating conditions. A comparative combustion data analysis using pressure-crank angle history and the captured endoscopic images was performed. An attempt was made to correlate the results of these two experimental investigations. Combustion duration (CD) obtained from the endoscopic images was relatively longer than the CD calculated from the thermodynamic analysis. Most research on soot and NOx emitted from the engine using a raw exhaust gas emission analyzer provides bulk, time-averaged, and cycle-averaged information about the pollutant formation. This investigation is unique wherein the spatial or time-resolved soot and NOx formation (Via spatial temperature distribution) are evaluated. The findings of this study support the research finding available in the open literature using an emission analyzer. This study and the technique therein on the deployment of engine endoscopy as an emerging optical technique is potentially useful to original automotive manufacturers (OEMs) in designing more efficient engines, capable of meeting upcoming stringent emission norms.

Journal ArticleDOI
15 Jan 2022-Fuel
Abstract: Modifications and improvements in fuel properties have become imperative to reduce engine-out emissions to comply with the existing and upcoming emission norms. Previous studies have demonstrated that using oxygenated fuels such as ethers and alcohols to augment diesel can reduce emissions significantly. An experimental investigation was performed to explore di-ethyl ether (DEE)-diesel blends on combustion, performance, and emissions characteristics of an off-road CI engine used in tractors. The test engine was fueled with three different DEE-diesel blends: DEE15 (15% v/v DEE and 85% v/v mineral diesel), DEE30 (30% v/v DEE and 70% v/v mineral diesel), DEE45 (45% v/v DEE and 55% v/v mineral diesel), and baseline mineral diesel. The engine was operated at a constant speed of 1500 rpm at varying engine loads, and results were compared. Peak in-cylinder pressure for DEE-diesel blends was lower than baseline diesel. At high loads, a relatively longer combustion duration was observed for DEE-diesel blends than baseline diesel. DEE-diesel blends exhibited slightly higher brake thermal efficiency (BTE), comparable exhaust gas temperature (EGT), and lower brake specific energy consumption (BSEC) compared to baseline diesel, owing to improved combustion of the oxygenated fuel blends. BSNOx emissions were relatively lower for all DEE-diesel blends compared to baseline diesel. The experimental investigations demonstrated that the test engine could work up to 45% (v/v) diesel substitution by DEE, without significant engine hardware modifications, but for low-to-medium engine loads only. At the highest substitution (DEE45), the test engine exhibited improved engine performance and lower NOx emissions than baseline mineral diesel operation. This experimental study demonstrated the potential for using DEE as a partial diesel substitute in the agricultural sector with significant performance and emission benefits.

Journal ArticleDOI
15 Jan 2022-Fuel
Abstract: The use of oxygenated fuels, including ethanol, methanol, diethyl ether (DEE), and dimethyl ether (DME) in CI engines has emerged as an effective way to reduce CO, HC, and PM emissions. DEE, in particular, has significant potential to be used in CI engines. Unlike DME, it exists as a liquid state at room temperature and pressure, making its handling very smooth. In this experimental study, DEE-diesel blends were used to power an off-road tractor engine. Previous studies investigated the performance and regulated emission characteristics of DEE-fueled vehicles/ engines; unregulated emissions and particulate characteristics were not studied thoroughly. This study, therefore, investigates the effect of DEE-diesel blends on unregulated and particulate emissions from the engine. Unregulated pollutants investigated in this study include individual oxides of nitrogen (NO, NOx, NO2), saturated and unsaturated hydrocarbons (n-pentane (n-C5H12), n-octane (n-C8H18), iso-butene (iso-C4H8)), and organic and inorganic species (Sulphur dioxide (SO2), formic acid (HCOOH) and formaldehyde (HCHO)). Particulate emission characteristics include total particle mass (TPM), total particle number (TPN), particulate mass-size distributions, and count mean diameter (CMD). Four test fuels were used in this study namely: DEE0, DEE15, DEE30 and DEE45 (0%, 15%, 30% and 45% DEE (v/v) blended with mineral diesel). The results from DEE-diesel blends were compared with baseline mineral diesel (DEE0). The experiments were conducted at a constant engine speed of 1500 rpm at varying engine loads. At all engine operating conditions, DEE-diesel blends resulted in significantly lower TPN compared to baseline mineral diesel. A similar trend was observed for TPM; however, DEE15 showed slightly higher TPM than baseline mineral diesel. Emissions of individual oxides of nitrogen were also relatively lower than baseline mineral diesel. The addition of DEE in mineral diesel exhibited a slight increase in unregulated emission species concentrations such as formaldehyde, formic acid, sulfur dioxide, n-pentane, n-octane, iso-butene. However, the absolute concentration levels were still quite low. This study concluded that DEE could potentially displace mineral diesel partially, without any changes in fuel injection equipment, and achieve an improvement in PM-NOx trade-off in off-road transport diesel engines.

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Journal ArticleDOI
Abstract: The present investigation accentuates the impact of Undi biodiesel blended diesel on combustion, performance, and exhaust fume profiles of a single-cylinder, four-stroke diesel engine. Five Undi biodiesel-diesel blends were prepared and tested at four variable loads over a constant speed of 1500 (±10) rpm. The Undi biodiesel incorporation to diesel notably improved the in-cylinder pressure and heat release rate (HRR) of the engine. The higher amount of Undi biodiesel addition enhanced the brake thermal efficiency (BTE) and brake specific energy consumption (BSEC) of the engine. In addition, the Undi biodiesel facilitated the reduction of the major pollutants, such as unburned hydrocarbon (UHC), carbon monoxide, and particulate matter (PM) emissions with slightly higher oxides of nitrogen emissions of the engine. To this end, a trade-off study was introduced to locate the favorable diesel engine operating conditions under Undi biodiesel-diesel strategies. The optimal results of the engine operation were found to be 32.65% of brake thermal efficiency, 1.21 g/kWh of brake specific cumulated oxides of nitrogen and unburned hydrocarbon, 0.94 g/kWh of brake specific carbon monoxide (BSCO), and 0.32 g/kWh of brake specific particulate matter (BSPM) for 50% (by volume) Undi biodiesel blend at 5.6 bar brake mean effective pressure (BMEP) with a relative closeness value of 0.978, which brings up the pertinence of the trade-off study in diesel engine platforms.

Journal ArticleDOI
Abstract: Experimental evaluation of cyclic variability or combustion instabilities of waste cooking oil biodiesel–diesel blends powered compression ignition engine is presented in this article. An advanced in-vehicle combustion analyzer armed with a piezoelectric pressure sensor was used for accurate measurements eradicating the experimental uncertainty. Cyclic variation in the combustion was investigated using the statistical and wavelet analysis method. Results of statistical methods and wavelet analysis were agreeing with each other toward self-validation. Statistical methods were used to calculate the mean and coefficient of variations, while the wavelet method has the potential to analyze the cyclic variation topography together with the intensity of variations in the engine combustion cycle, especially at low engine load conditions. Overall combustion analysis including wavelet analysis and statistical method indicates a more silent and smoother engine operation with biodiesel blending as it enhances combustion stability in unmodified diesel engines in comparison with conventional diesel fuel.

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Author's H-index: 53

No. of papers from the Author in previous years