Improving the Determination of Mass Fraction Burnt 900351

The Rassweiler and Withrow method for determining mass fraction burnt from S.I. engine cylinder pressure data is widely used, but implementation details vary. The best form of implementation, and the effect of uncertainties in the assumptions made, have been investigated. Attention has been given to determining the end of combustion, the effect of signal noise on the pressure data, the effect of assumptions regarding the value and variation of apparent compression and expansion polytropic indices and, particularly, how these should be determined. The treatment of late burning cycles is also discussed. Versatile software has been developed for idle to full load studies with good tolerance to signal noise.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 40% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.