Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4991592 | Applied Thermal Engineering | 2017 | 25 Pages |
Abstract
The sensitivity of each Wiebe parameter, namely, the efficiency factor (a), form factor (m), crank angle of combustion start (Ï0), and combustion crank angle duration (ÎÏ), is analysed to ensure that these parameters are estimated reasonably and precisely. The sensitivity of each Wiebe parameter is roughly positively associated with the heat release rate normalized by the total fuel energy. The sensitivities of m and Ï0 are larger than the sensitivities of a and ÎÏ. m and Ï0 should be estimated carefully, while a and ÎÏ can be roughly confirmed. All of sensitivities, the signal-to-noise ratio in cylinder pressure and the certainty in the heat release analysis in the middle stage of combustion are larger than in the early and last stages. Therefore, it is reasonable and necessary to ignore the early and last stages of the combustion process during the confirmation of the Wiebe parameters. The estimated value of Ï0 using the 50-per cent burnt angle, the angle associated with the maximum value of the sensitivity of Ï0 and ignition time are Ï0-50, Ï0-smax and Ïignite. The simulation results indicate that, compared with Ïignite and Ï0-50, Ï0-smax is the most suitable to be set as Ï0 in standard and double Wiebe functions.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Song Hu, Hechun Wang, Chuanlei Yang, Yinyan Wang,