Spark-ignition engine

About: Spark-ignition engine is a research topic. Over the lifetime, 4352 publications have been published within this topic receiving 66550 citations.

Comparative Performance of Alcohol and Hydrocarbon Fuels

Abstract: Calculated and experimental comparative performance characteristics of alcohols (methanol and ethanol) and hydrocarbons (octane and benzene) as spark ignition engine fuels are presented. These characteristics were derived from analysis of relative amounts of combustion products produced per unit of inducted charge, energy in the charge, and latent heat of evaporation. The thermodynamic properties of methanol and air, ethanol and air, and benzene and air were also analyzed. Differences in the stoichiometry and thermochemistry of the hydrocarbons and alcohols confirm the observed increase in power output with ethanol and methanol, in particular, as engine fuels. Accompanying any increase in output is a disproportionate rise in fuel consumption. Principal factors influencing output are the product volume/inducted charge volume and the fuel latent heat as it may influence compression work. More sophisticated analysis, based upon thermodynamic charts of combustion products, do not necessarily improve correspondence between calculated and experimental results.

Combustion Analysis of a CNG Direct Injection Spark Ignition Engine

Abstract: An experimental study was carried out on a dedicated compressed natural gas direct injection (CNG-DI) engine with a compression ratio (CR) of 14 and a central injection system. Several injection timing parameters from early injection timing (300 BTDC) to partial direct injection (180 BTDC) to full direct injection (120 BTDC) were investigated. The 300 BTDC injection timing experiment was carried out to simulate the performance of a port injection engine and the result is used as a benchmark for engine performance. The full DI resulted in a 20% higher performance than the early injection timing for low engine speeds up to 2750 rpm. 180 BTDC injection timing shows the highest performance over an extensive range of engine speed because it has a similar volumetric efficiency to full DI. However, the earlier injection timing allowed for a better air–fuel mixing and gives superior performance for engine speeds above 4500 rpm. The engine performance could be explained by analysis of the heat release rate that shows that at low and intermediate engine speeds of 2000 and 3000, the full DI and partial DI resulted in the fastest heat release rate whereas at a high engine speed of 5000 rpm, the simulated port injection operation resulted in the fastest heat release rate.