Insights into the Role of Autoignition during Octane Rating University of Cape Town

Format:

Conference/Event

Author/Creator:

Swarts, André, author.

Conference Name:

2007 Fuels and Emissions Conference (2007-01-23 : Cape Town, South Africa)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2007

Summary:

The paper describes the emulation of the knock measurement equipment on the CFR engine used during octane rating. It was found during engine measurements that the low-pass filtered rate-of-change of the pressure signal from Primary Reference Fuels (PRF) established the definitive metric of standard knock intensity and that non-PRF fuels exhibited similar pressure rise rates at standard knock intensity. The effect of fuel octane number, compression ratio and air-fuel ratio was also clearly distinguishable.Further modelling interpretation revealed that a non-instantaneous, cascading autoignition was a likely origin for the measured pressure development. Thermal inhomogeneities, which were the result of a heat loss gradient in the trapped mass, served to explain the observed behaviour of both RON and MON test conditions and a range of fuels of different octane numbers. A predictive model was ultimately applied to demonstrate that the pressure development and pressure rise rate can be predicted from the physical conditions in the engine, coupled to a fuel ignition delay descriptor

Notes:

Vendor supplied data

Publisher Number:

2007-01-0008

Access Restriction:

Restricted for use by site license