Flow Analysis during Soot Trapping on Aluminum Titanate Ceramics Filter with Hexagonal Cell Geometry

The phenomena of soot trapping and oxidation in a hexagonal cell geometry DPF made of aluminum titanium oxide were investigated through microscopic visualization experiment and a simple analysis based on Darcy’s law through the wall and the deposited soot layer. There were two types of flow: one was a flow through a wall between inlet and outlet channels (inlet/outlet wall flow), and the other was a flow which was introduced into a wall between inlet and inlet channels, and was turned toward the direction parallel to the wall, and finally exited into the outlet channel (bypass flow). The flow rate of the bypass flow was increased with a thickness of soot layer deposited on the inlet/outlet wall. As a result, the soot was trapped even on the inlet/inlet wall surface. In the regeneration process, depending on the flow rate of the bypass flow, the maximum temperature for the hexagonal cell DPF became lower compared with that for the conventional DPF.