| 摘要 |
PROBLEM TO BE SOLVED: To accurately estimate an air-fuel mixture concentration in consideration of various phenomena varying the degree of the mixing of a fuel with a cylinder gas in the process of an air-fuel mixture moving in a combustion chamber. SOLUTION: This air-fuel mixture concentration estimating device provides the excess air ratioλof the air-fuel mixture by multiplying the value of an air-fuel mixture dilution rate (dλ/dt) base calculated from a general expression obtained by utilizing the low of conservation of momentum by the dilution factors K1, K2, K3 corresponding to breakup, evaporation, and thermal expansion to correct the air-fuel mixture dilution rate and integrating the corrected air-fuel mixture dilution rate ((dκ/dt)base*K1*K2*K3). The dilution factors k1, K2, K3 are all set to [1] when an elapsed time after injection is t=0. When the breakup of the air-fuel mixture occurs (t=t1), only K1 is changed to a value larger than [1] thereafter. When a droplet fuel in the air-fuel mixture is evaporated (t=t2), the dilution factor K2 is set to less than [1] thereafter, and the dilution factor K3 is set to a value larger than [1]. COPYRIGHT: (C)2007,JPO&INPIT
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