Oblique inlet pressure loss for swirling flow entering a catalyst substrat

This experimental study investigates the oblique inlet pressure loss for the entry of an annular swirling flow into an automotive catalyst substrate. The results are applicable to a wide range of compact heat exchangers. For zero swirl, the total pressure loss agrees with established expressions for pressure loss in developing laminar flow in parallel channels with finite wall thickness. For positive swirl, the additional pressure loss due to oblique flow entry is correlated to the tangential velocity upstream of the catalyst, measured using laser-Doppler anemometry. The obtained oblique inlet pressure loss correlation can improve the accuracy of numerical calculations of the flow distribution in catalysts.