Dimension reduction model for auto-ignition in micro flowreactor with controlled temperature profile

A simplified modeling strategy with dimension reduction (1-D to 0-D) was presented for auto-ignition in a micro flowreactor with controlled temperature profile. Since diameter of the reactor channel was chosen to be equal to or smaller than the ordinal quenching diameter, flow field in the reactor channel can be modeled as a plug flow with controlled temperature profile only in a flow direction given by an external heat source. Then, auto-ignition in a straight channel with controlled temperature profile can be described as spatially zero-dimensional, transient problem by defining a control volume flowing in the channel which has convective heat transfer with heated wall and volumetric expansion at constant pressure. As a result, computational load of the given system can be drastically reduced. Auto-ignition temperatures for stoichiometric methane-air mixture estimated by the proposed model using GRI-mech 3.0 were in good agreement with those by our previous experiments. Auto-ignition temperatures calculated using C1-chemistry completely disagree with those using GRI-mech 3.0, while those using GRI-mech 2.11 and 1.2 agree. A normalized sensitivity coefficient suitable for auto-ignition in the micro flowreactor was proposed. The present sensitivity analysis identified important elementary reactions for auto-ignition.