An estimation of quench-gas bias in internal combustion engine in-cylinder sampling

✍ Scribed by S.R. Turns; G.L. Borman

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 779 KB
• Volume: 39
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(80)90010-3

✦ Synopsis

A simplified empirical-analytic model of flame quenching and subsequent removal of probe boundary-layer gases during in-cylinder sampling was used to study the quench-bias problem. For conditions similar to those of a diesel cylinder the model showed that the flame temperature has the greatest influence on the mass fraction of quench gas in a sample; cylinder pressure, orifice size, and sampling interval have less influence. For flame temperatures greater than 1900°K, the quench-mass fraction was computed to be relatively small--about 4% of the total mass. Even when the hydrodynamic boundary layer is neglected, the quench gas assumed at a uniform temperature equal to the wall temperature and the flame temperature taken at 2222°K, the quench-mass fraction is calculated to be only 9 to 16%. Extension of the model to the case where the bulk gas is flowing did not alter the conclusion that quench bias appears to be relatively unimportant in high temperature regions.