An Experimental and Computational Study of Flow Characteristics in Exhaust Manifold and CCC (Close-Coupled Catalyst)

Experimental study of flow dynamics in close-coupled catalyst manifolds

“…Regardless of differences in exhaust system geometries, the findings of the present research are in agreement with those of Adam et al [8], Liu et al [9], Park et al [10] and Benjamin et al [11]. §3.2 discusses and explains the Helmholtz resonances observed in the current study.…”

“…The results by the aforementioned authors [8,9,10,11] indicate strong flow reversal immediately following blowdown. The occurrence of reverse flow throughout the engine operating range may be surprising, considering the pressure drop generated by the CC catalyst.…”

“…Park et al [10] present experimental data obtained using phase-locked LDA on a fired engine. The time-resolved runner velocity shows typical fluctuations at frequencies consistent with a Helmholtz resonance.…”

“…However, the exit cone cannot be solely responsible for the occurrence of flow reversal. Liu et al [9], Park et al [10], Benjamin et al [11] and Kim et al [12] present experimental or numerical results showing reverse flow in a CC catalyst monolith in fired conditions, including an outlet section. Reverse flow consistently occurs after blowdown.…”

“…Park et al [10] present experimental results using LDA for a close-coupled catalyst exhaust manifold, mounted on a fired engine. Figure 5 in their paper shows the velocity in runner #3 for 2000 rpm at part load.…”