Modeling End-Gas Autoignition of Ethanol/Gasoline Surrogate Blends in the Cooperative Fuel Research Engine

Abstract

This paper presents an experimental and numerical investigation of the autoignition of ethanol blended with several primary reference fuels (PRFs) and toluene reference fuels (TRFs) in a Cooperative Fuel Research (CFR) engine. Autoigniting, in-cylinder pressure traces are acquired under standard research octane number (RON) conditions. Equivalent, non-autoignitiing traces are obtained by adding a small amount of tetraethyl lead (TEL) to each fuel to suppress knock, and these are used to calibrate a two-zone engine model of autoignition. The simulated autoignition timing of the PRFs without ethanol, TRFs without ethanol, and ethanol/PRF and ethanol/TRF blends are then compared to those measur..