Measuring velocity and turbulent diffusivity in wall-flow filters using compressed sensing magnetic resonance
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Elsevier
https://doi.org/10.1016/j.cej.2018.08.076
https://doi.org/10.1016/j.cej.2018.08.076
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Gas-phase compressed sensing magnetic resonance methods have been used to image gas flow velocity and turbulent diffusivity in wall-flow particulate filters. Two-dimensional magnetic resonance velocity imaging was used to observe the local distribution of gas velocity in the direction of superficial flow (z) in the entrance and exit regions of the filter at an in-plane spatial resolution of 140 µm (x) × 140 µm (y) and 140 µm (x) × 390 µm (z) perpendicular to and parallel with the direction of superficial flow, respectively. Images were acquired in 14 min. Three-dimensional images of the turbulent diffusivity were acquired at a spatial resolution of 280 µm (x) × 280 µm (y) × 1250 µm (z) for channel Reynolds numbers, Rec, of 210, 360, 720 and 1140. These data provide evidence of regions of turbulence inside the filter that has not been predicted by earlier numerical simulations. For Rec = 1140, a three-dimensional velocity image was also obtained at the same spatial resolution as the image of turbulent diffusivity; the data acquisition time was 2 h. Co-registration of these two images enables visualisation of the spatial extent and magnitude of these two characteristics of the flow field.
JDC would like to thank Johnson Matthey and the EPSRC for a CASE award (award reference 1628588).
JDC would like to thank Johnson Matthey and the EPSRC for a CASE award (award reference 1628588).