Experimental and numerical study of flow passing through a series of angled plates*

Air pollution capturing techniques have gained considerable attention over the past few decades as air pollution has significantly increased. For instance, selective catalytic reduction (SCR) systems eliminate nitrogen oxide (NO_x) within a catalyst. Our previous studies have revealed that the uniformity of the flow entering the catalyst is a key factor in regards to efficiency. Often, flow straighteners are placed above the catalyst to straighten out the flow, turning around a corner. Thus, we intended to examine the effect of straightener ribs on flow uniformity in this research by utilizing particle image velocimetry (PIV) and large eddy simulation (LES). The flat straightener ribs are emulated by multiple parallel plates. Two variables are considered: the flow angle of attack and the separation distance between the plates. Compared to a single plate, the results illustrated a substantial difference in the wake size and shedding frequency, which varies from the first to last plate. This variation is due to multiple mechanisms related to the interaction of neighboring plates. The results are anticipated to provide insightful data and reveal mechanisms involved in the flow separation and vortex shedding from a straightener at an intermediate Reynolds number of 10,000. This will help design more efficient SCR systems.