Lawand, Vaibhav (2009-12). Use of a Thermodynamic Engine Cycle Simulation to Study a Turbocharged Spark-ignition Engine. Master's Thesis. Thesis uri icon

abstract

  • The second law analysis is a powerful tool for assessing the performance of engines and has been employed for few decades now. Turbocharged diesel engines have been explored in much detail with the help of second law analyses. There is also a need to examine the turbocharged spark-ignition engines in greater detail using second law analyses as they are gaining popularity in high performance and conventional automobiles as well. A thermodynamic simulation was developed in order to investigate the effects of turbocharging on spark-ignition engines from second law perspective. The exergy values associated with the components of the turbocharger along with the engine components were quantified as a percentage of fuel exergy. The exergy balance values indicated that turbocharger does not add considerably to the overall irreversibilities and combustion irreversibility is still the major source of exergy destruction. A comprehensive parametric investigation was also performed to investigate the effects of compression ratio, intercooler effectiveness, etc. for the turbocharged spark-ignition engine over the entire load and speed range. The simulation studies helped in understanding the behavior of turbocharged sparkignition engine with these parameters. A simulation study was also performed to compare the turbocharged engine with the naturally aspirated spark-ignition engine. This study examined the engines for operating parameters like bmep and bsfc over the entire speed range and revealed that turbocharging offers higher bmep and lower bsfc values for most of the operating range. In an additional study, these engines were analyzed for the brake thermal efficiency values at part load. The results indicated that turbocharging offers marginally higher brake thermal efficiency at part loads.
  • The second law analysis is a powerful tool for assessing the performance of engines
    and has been employed for few decades now. Turbocharged diesel engines have been
    explored in much detail with the help of second law analyses. There is also a need to
    examine the turbocharged spark-ignition engines in greater detail using second law
    analyses as they are gaining popularity in high performance and conventional
    automobiles as well. A thermodynamic simulation was developed in order to
    investigate the effects of turbocharging on spark-ignition engines from second law
    perspective. The exergy values associated with the components of the turbocharger
    along with the engine components were quantified as a percentage of fuel exergy. The
    exergy balance values indicated that turbocharger does not add considerably to the
    overall irreversibilities and combustion irreversibility is still the major source of exergy
    destruction. A comprehensive parametric investigation was also performed to
    investigate the effects of compression ratio, intercooler effectiveness, etc. for the
    turbocharged spark-ignition engine over the entire load and speed range. The
    simulation studies helped in understanding the behavior of turbocharged sparkignition
    engine with these parameters.
    A simulation study was also performed to compare the turbocharged engine with the
    naturally aspirated spark-ignition engine. This study examined the engines for
    operating parameters like bmep and bsfc over the entire speed range and revealed
    that turbocharging offers higher bmep and lower bsfc values for most of the operating
    range. In an additional study, these engines were analyzed for the brake thermal efficiency values at part load. The results indicated that turbocharging offers
    marginally higher brake thermal efficiency at part loads.

publication date

  • December 2009