Theoretical Study of the Effects of Spark Timing on the Performance and Emissions of a Light-Duty Spark Ignited Engine Running under Either Gasoline or Ethanol or Butanol Fuel Operating Modes

Abstract

Much research is ongoing to find suitable alternate fuels in order to reduce the exhaust emission levels without deteriorating the basic performance characteristics of conventional spark-ignited (SI) engines. One of the methods to achieve the above problem is the use of alcohols as full supplement fuels to normal gasoline. At the same time, many related research studies have shown that the use of alcohols has a negative impact on some basic engine performance characteristics, e.g., brake power output, etc. On the other hand, spark timing is one of the critical engine operating parameters that significantly influences the combustion mechanism inside the combustion chamber of a SI engine. Therefore, the primary objective of the present work is to investigate the effect of spark timing on the performance and emissions characteristics of a conventional, four-stroke, SI engine running under three different fuel operating modes, viz. with conventional gasoline or ethanol or butanol. The specific investigation is conducted by using an in-house, comprehensive, two-zone phenomenological model. The predictive ability of the model is tested against pertinent experimental data and it is found that the computed results are in good agreement with the respective experimental ones. For all test cases examined herein, the results concern basic engine performance characteristics, i.e., cylinder pressure, power output, specific fuel consumption etc., as well as NO and CO emissions. The main objectives of the work were to record and evaluate the impact that spark timing has on the performance characteristics and emitted pollutants of a conventional SI engine, operating under either conventional gasoline or ethanol or butanol fuel operating modes. Moreover, it deals with the determination of an optimum combination between the type of fuel used and the spark timing, so that probable undesirable effects on engine performance characteristics would be avoided. By comparing this investigation results, it is revealed that the use of alcohols as a full substitute fuel of gasoline accompanied with an appropriate alteration of the spark timing, could be a promising solution to improving both the efficiency and environmental behavior of a light-duty, spark-ignited (SI) engine, without causing any harmful problems to the engine operational lifetime. The conclusions from the study may prove valuable for the application of this technological solution to existing conventional SI engines.

Investigation on the Potential of High Efficiency for Internal Combustion Engines

“…The energy consumption of internal combustion engines has caused a substantial negative impact on the ecological environment and energy security. Moreover, the ever-increasing energy demands, coupled with their detrimental environmental effects, have guided research to seek alternative fuels for gradually substituting conventional ones [3][4][5][6][7][8][9][10][11]. However, it should be noted that improving engine efficiency is the primary option to reduce energy consumption and greenhouse gas emissions simultaneously.…”

Evaluation of the Air Oxygen Enrichment Effects on Combustion and Emissions of Natural Gas/Diesel Dual-Fuel Engines at Various Loads and Pilot Fuel Quantities

“…Strong motivation emanating from the necessity to advance both the performance and emission attributes of internal combustion engines, have forced scientists and engineers working in this arena to conceive and propose various technological solutions [1]. Such solutions include diverse techniques linked to either the design and operating engine conditions [2][3][4][5][6] or to the use of various types of alternative fuels, such as liquid bio-fuels [7][8][9][10][11] or gaseous fuels (e.g., natural gas) [12][13][14][15][16]. A number of gaseous fuels such as natural gas, liquefied petroleum gas (LPG), hydrogen, biogas, coal gas, and methanol, are considered as good alternative fuels for cars, trucks or stationary engines applications, as they accomplish several of the critical requirements of a fuel, such as abundance, domestic availability, non-expensive energy, safety in use, clean combustion, etc.…”

Diesel and Spark Ignition Engines Emissions and After-Treatment Control: Research and Advancements

“…In this paper, various blends of biodiesel (consisting of rapeseed oil, soybean oil and recycled cooking oils) with diesel fuel are under consideration, ranging from 20 to 100% (neat biodiesel). Two other papers focus on SI engine operation; Papagiannakis et al [5] report on the theoretically-studied effects of spark timing on the performance and emissions of a single-cylinder, four-stroke, light-duty SI engine running under gasoline, (neat) ethanol or (neat) butanol fuel operating modes. Unlike their conventional counterparts, direct injection SI (DISI) engines, being characterized by partially premixed combustion resembling that of the compression ignition engine, are not exempt from PM emissions; actually this is something that has been reflected in the European legislation beginning with the Euro 5 emission standard.…”

“…The articles contained in the Special Issue "Automotive Engines Emissions and Control" [4][5][6][7][8][9][10][11][12][13] were published online by Energies between September 2016 and October 2017; they deal with various issues of automotive engines emissions and after-treatment control. Both diesel and spark ignition engines are covered, under stationary and transient conditions.…”

“…There are four papers that incorporate in their analysis the effects of biofuels [4][5][6][7], two on diesel and two on SI engines operation. This is actually a very timely subject, as biofuels, being by nature renewable, can offer distinctive advantages over conventional fuels.…”