AN EXPERIMENTAL-STUDY OF FLOW AND THERMAL TRANSIENT-RESPONSE IN A RACE-TRACK MONOLITH CATALYTIC-CONVERTER

A model for the pressure drop was proposed and compared to experimenta l results. Global flow characteristics and velocity distribution were studied from residence time distribution measurements in a ''race-trac k'' monolith. Significant dead volumes were detected and the velocity distribution was determined. The effect of flow-rate, inlet tube diame ter and flow deflector was investigated. Study of the time evolution o f outlet temperature and temperature distribution in a monolith coated or not with catalyst makes it possible to determine the thermal chara cteristics of heat-up. The influence of flow rate, velocity distributi on and developing laminar flow regime in the channel were qualitativel y estimated. Theses results allow one to determine the hydrodynamic an d thermal behavior of the catalytic converter and to propose reliable and realistic assumptions for subsequent modeling.