Experimental and Numerical Investigation of Iso-Octane, Methanol and Ethanol Regarding Laminar Burning Velocity at Elevated Pressure and Temperature

Abstract

<div class="htmlview paragraph">The laminar burning velocity is one key parameter for the numerical simulation of gasoline engine combustion processes. In order to understand the effect of the laminar burning velocity of different fuel components on modern engine development it is of great interest to conduct experiments under high initial pressure and temperature. Initial conditions in this publication are a pressure of p = 10bar and a temperature of T = 373K.</div> <div class="htmlview paragraph">Special focus has been laid on the common C1 and C2 alcohols, methanol and ethanol, which are frequently used for blending components in standard gasoline.</div> <div class="htmlview paragraph">The experimental setup consists of a spherical closed pressurized combustion vessel with optical access. Schlieren measurements coupled with a high speed camera are used for image acquisition to track the expanding flame front. Finally, a post processing tool is used to extrapolate the measurements to zero stretch.</div> <div class="htmlview paragraph">Experiments were done at different fuel-air ratios between Φ = 0.8 and up to Φ = 1.2. Test fuels were the pure component iso-octane, methanol and ethanol or mixtures iso-octane / methanol and iso-octane / ethanol with a maximum blend rate of 10% vol<sub>liq</sub> regarding the alcohol.</div> <div class="htmlview paragraph">Thereafter, numerical simulations using high temperature chemical models were undertaken to estimate the laminar burning velocity for a distinct amount of experimental test points.</div> <div class="htmlview paragraph">Experimental results are discussed in detail and compared with the numerical simulations as well as references from literature.</div>