Increased awareness of health effects from microscopic dust particles is leading to a rising demand for particulate filters in diesel cars and trucks. Simulations for filter design and especially for the study of their regeneration behaviour are needed to improve their layout. This paper shows the current state of a detailed one-dimensional model developed at J. Eberspächer GmbH & Co. KG based on a pair of channels. Results for pressure drop, soot loading and mainly for regeneration are shown. This model is being implemented by Fluent Inc. into the code FLUENT as a User Defined Function (UDF). Hence, a combined 1D/3D-mode! is generated with which the effect of the three-dimensional inflow and surroundings can be considered without losing the advantage of a low cell count from a one-dimensional channel model. Current progress will be shown in this paper. The one-dimensional model will be coupled with FLUENT as a UDF by Fluent Inc. The aim here is to achieve a CFD model of a particulate filter that fulfils the requirements of realistic filter behaviour. In particular, a detailed regeneration approach is needed that describes partial regenerations by considering the incoming flow and the temperature losses to the environment. The combined model will solve a special number of single channels that interact with each other directly by heat conduction and indirectly by a change of the distribution of the inlet mass flow. Considering the commonly used brick structure of SiC-filters will be an option. Only then will it be possible to simulate effects as shown. It is illustrated a filter after a special regeneration process in which only the area behind the central efflux of the filter was regenerated whereas the cooler edge regions are still full of soot.