The tool will simulate full-scale catalytic converters with realistic chemistry in less than overnight turnaround time. The simulator will support on the order of 1000 channels with implicit coupling between fluid flow, heat transfer (including conjugate heat transfer), mass transfer, and heterogeneous chemical reactions. This will allow catalytic converter developers to explore several design modifications including the size of the converter, the number of channels per square inch of the monolith, the flow rate, and the catalyst loading, among others. This will make catalytic converter modeling more useful and affordable to the industry, especially for small/mid-sized manufacturing and engineering firms.