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Ignition Flame Kernel Growth Under Idle Simulated Conditions

Conference ·
OSTI ID:5952600
 [1];  [1]
  1. Pennsylvania State Univ., University Park, PA (United States)

At idle operation, current spark ignition engines typically exhibit what is referred to as "engine roughness". This is generally attributed to poor ignition quality as a result of the relatively low temperature, low pressure, dilute charge conditions at idle operation. More specifically, however, it is a consequence of the slow and non-repeatable growth of the ignition flame kernel immediately following ignition. In this study, ignition flame kernel growth has been studied in a turbulent flow reactor under conditions which simulate the turbulent flow field in an engine at idle operation. The experiments were conducted with a propane-air equivalence ratio of 1.0, at a pressure of 1 atmosphere, temperature of 300 K, mean velocity of 1 m/sec, turbulence intensity of 0.5 m/sec and turbulence integral length scale of approximately 3 mm. Of particular interest were the effects of charge dilution and ignition energy on the ignition flame kernel growth rate and its variation. Charge dilution, which can be as high as 30 percent at idle, was varied between 0 and 30 percent with nitrogen addition. Ignition was achieved with standard automotive systems, arranged to supply variable energy and duration sparks using standard plugs.

Research Organization:
Pennsylvania State Univ., University Park, PA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE); US Air Force Office of Scientific Research (AFOSR)
DOE Contract Number:
AS04-86AL38027
OSTI ID:
5952600
Report Number(s):
CONF-881215--5; ON: DE92006777
Resource Relation:
1988 Fall technical meeting of the Eastern states section of the Combustion Institute, Clearwater Beach, FL (United States), 5-7 Dec 1988
Country of Publication:
United States
Language:
English