CD-adapco will be demonstrating an exciting new approach for simulating Diesel Particulate Filters at the upcoming SAE 2006 Commercial Vehicle Engineering Congress and Exhibition (October 31 to November 2, Donald E. Stephens Convention Center, Rosemont Illinois).
The current generation of DPFs are complex thermo-chemical devices that are subject to numerous potential failure modes, not all of which are can be easily captured for robust vehicle calibration, and which therefore are potentially the cause of serious warranty issues. Until recently the numerical modeling of DPFs has been prohibitively difficult, due to unique difficulties in accurately accounting for flow physics, chemical kinetics and conjugate heat transfer. However, in response to considerable demand from the automotive industry, CD-adapco has recently undertaken a comprehensive industrial validation exercise to assess the DPF prediction capabilities of es-aftertreatment, their dedicated tool for the numerical analysis of aftertreatment devices.
es-aftertreatment simulates both the DPF proper, and the Diesel Oxidation Catalyst that sits just upstream of it, through both soot loading and regeneration cycles. By using a multiple representative channel approach es-aftertreatment captures the full 3D detailed flow characteristics both upstream and downstream of monolith and accounts for the conjugate heat transfer of the entire system. In each channel both the catalytic and gas phase reactions are modeled using a detailed chemistry solver.
The validation exercise took place using a DPF geometry and experimental data kindly provided by the Ford Motor Company, and produced generally excellent results es-aftertreatment accurately predicted the actual soot loading mechanism, by which any non-uniformity in the initial soot distribution causes a self-correcting blockage, resulting in a fairly even distribution of soot throughout the "dirty" filter. Using model parameters freely available in existing literature, the predictions were qualitatively and many instances quantitatively in agreement with the pressure probe and thermal couple measurements, demonstrating that es-aftertreatment is a powerful tool in DPF design.
For more information on CD-adapco, STAR-CD or es-aftertreatment, please visit:
CD-adapco is the leading global provider of full-spectrum engineering simulation solutions for fluid flow, heat transfer and stress, including CFD software, CAD-embedded CFD options, CAE consulting services and training.