The surface structure of different needled felts can be characterized quantitatively by a few key parameters, which are used to build model structures in a simple way. These model structures are then used to simulate the cake-forming dust filtration via CFD simulation and calculation of particle trajectories. By systematic variation of the key parameters for simulation calculations, the changes in the dust cake structure and in the operating behavior of surface filters from differently structured needled felts can be evaluated for a systematic theoretical study.