Numerical investigation of honeycomb channel design: Effect of rounded corners on selective catalytic reduction of NO

Abstract

In this work, single-channel models are established to investigate the effect of rounded corners on overall performance of honeycomb catalyst with various channel geometries and cell densities (Ncell). As channel shape factor (γ) increases, pressure drops all rise slowly at low γ (0 ∼ 0.5) and increases dramatically when γ > 0.5, aligning with monolith voidage and hydraulic diameter variations. Hexagon-channel catalysts with open corners exhibit the smallest pressure drop increase (17.3 %), while triangle-channel catalysts with acute corners show the highest rise (100.1 %). The increase in Ncell leads to a similar rise (43 %) in pressure drop. NO conversions decrease with γ due to reduced external surface area, with maximum conversions observed for triangle-channels (low γ) and hexagon-channels (high γ). Increasing Ncell enhances NO removal and mitigate rounded-corner effect on conversion (4.5 % to 1.2 % reduction). Based on that, a design strategy suggesting γ = 0.5 is proposed to eliminate ash accumulation and maintain acceptable catalyst performance.