3-D Transient Elastic Thermal Stress Field during Diesel Particulate Filter Regeneration

A displacement based finite element model is developed to predict 3-D thermal stress induced by high temperature and temperature gradient during diesel particulate filter (DPF) regeneration. The temperature field predicted by 3-D conservation of energy is used as input. This finite element model is self-contained and independent of commercial package. It includes functions of meshing body, assembling global stiffness matrix and force vector, solving final equilibrium equations as well as post-processing. This model is validated by commercial software ANSYS and good agreement is observed. Typically, it is the peak temperature rather than temperature gradients that lead to maximum compressive thermal stress in DPF during regeneration. The maximum stress always appears at the channel corner located at the end of DPF. Parametric studies of DPF during loading and regeneration as well as the effect of particulate loading on thermal stress during regeneration are carried out. This model can provide insight to the physical processes in the DPF and can be used as an engineering tool for DPF design.