Diesel Particulate Filter (DPF) Challenges

Diesel Particulate Filter (DPF) challenges
The innate challenges of DPF include the following although the filtration efficicency is greater than 70%. (1) Pressure in the exhaust system increases even when the filter gets cleaned (2) Steady increase in pressure rise had been found during soot filtration (3) Soot doesn’t ignite or oxidize during normal diesel engine operation (4) Soot burning process needs to be carefully controlled as excessive temperature might damage the trap structure [2,3].
Several studies and research focus on addressing these challenges through associated technologies [2,3].
This paper focusses on the CFD modeling of cyclone based exhaust system with the aim of complementing DPF during their operation.

Proposed system

Kh.Elsayed et al [5] examined Cyclones for their

geometric simplicity and relative economy in power consumption. They are relatively maintenance-free as there are no moving parts. Few researchers indicate that cone is not essential for cyclone separation although it helps in delivering collected particles to the central discharge point. Effects of cone dimensions on the flow field of cyclone separators had been studied using LES model in CFD. It has been found that LES results agree with Xiang’s experiment that cyclone with a smaller cone tip diameter results in higher pressure drop when compared to a cyclone with a bigger cone diameter

Xiang et al [6] performed experiments with cyclones of different cone dimensions and are qualitatively validated by few models, namely Barth, Leith and Licht and Iozia and Leith. Xiang’s experimental results reveal that cyclones with a smaller cone diameter result in a slightly higher collection efficiency when compared to cyclones with a bigger cone tip diameter. Change in pressure drop was not significant when the cone size was

It has been found that tangential velocity is axially constant in the cylinder-on-cone cyclone whereas the tangential vecity decreases slightly as it descends down the cyclone. Radial velocity is fairly uniform over the length of the separation zone in the cylinder-on-cone cyclone except for a localized lip leakage. Inward flow is largely limited to regions of strong inward velocity under the votex finder and in the bottom of the body. CFD results agree well with LDA