Heat transfer coefficient on the combustion chamber wall surfaces in a naturally aspirated direct-injection diesel engine

Autor: Yoshiteru Enomoto, Yuta Aoki, Shuji Kimura, Masahiko Emi
Rok vydání: 2013
Předmět:
Zdroj: International Journal of Engine Research. 15:606-625
ISSN: 2041-3149
1468-0874
DOI: 10.1177/1468087413500060
Popis: Thin-film thermocouples were used to measure the instantaneous temperature at 100 points on all the combustion chamber wall surfaces in a naturally aspirated direct-injection diesel engine. Instantaneous heat flux at each measured point was also obtained through heat transfer analysis with the measured instantaneous wall surface temperature applied as a boundary condition. In addition, the instantaneous mass-averaged gas temperature in the combustion chamber was calculated through the equation of state of an ideal gas. As a result, the local and overall heat transfer coefficients were evaluated using the corresponding wall surface temperatures and heat fluxes. The overall heat transfer coefficients thus obtained were compared with those calculated with Eichelberg’s and Woschni’s empirical equations for five ignition timings and three engine speeds. As a result, it was revealed that an overall average heat transfer coefficient obtained through the authors’ experiments has characteristics different from those of the heat transfer coefficients calculated from the empirical equations proposed by Eichelberg and Woschni.
Databáze: OpenAIRE