This paper presents the results of studies on a range of different catalyst substrates warmed by engineexhaust. Engine speeds were in the range 1200 to 3000 rpm. One substrate was non-washcoated, fourwere washcoated but non-reactive, and four were washcoated and reactive. The temperature at fourlocations within the non-reactive substrates was measured. The reactive substrates were warmed tolight off by the pulsating exhaust flow from an engine running fuel rich of stoichiometric. Bothsubstrate temperatures and hydrocarbon conversion were measured. Predicted temperatures andconversion were obtained from a 1D CFD model. The model was based on the porous mediumapproach and incorporated a simple 3-way chemical scheme. Comparison was made of measurementswith predictions, with particular reference to the time taken to achieve light-off. Pulsing flow CFDpredictions were found to be almost identical to steady flow predictions for the conditions investigated.The CFD predictions were found to be in fair agreement with the engine test results, but using kineticrate constants higher than previously reported values
