This study investigates oblique entry pressure loss in automotive catalyst monoliths. Experiments have been performed on a specially designed flow rig using different lengths of monolith (17—100 mm) over a range of Reynolds number and angles of incidence (0–75°). Losses were found to be a function of Reynolds number and angle of incidence and a general correlation has been derived. Computational fluid dynamics predictions of the flow distribution across axisymmetric catalyst assemblies have been performed. Incorporating the oblique entry loss provided much better agreement with experimental data with the assumption that such losses were constant above an angle of incidence of 81°.
LaiM. C.KimJ. Y.ChengC. Y.LiP.ChuG.PakkoJ. D., ‘Three-dimensional simulations of automotive catalytic converter internal flow’ (1991): SAE paper 910200.
2.
KimJ. Y.LaiM. C.LiP.ChuG., ‘Modeling diffuser-monolith flows and its implications to automotive catalyst converter design’ (1992): SAE paper 921093.
3.
BenjaminS. F.ClarksonR. J.HaimadN.GirgisN. S., An experimental and predictive study of flow in axisymmetric automotive exhaust catalyst systemsSAE Trans., J. Fuels Lubr.105 4 (1996): 1008–1019.
4.
BenjaminS. F.HaimadN.RobertsC. A.WollinJ., Modelling the flow distribution through automotive catalytic convertersProc. IMechE, Part C: J. Mechanical Engineering Science215 C4 (2001): 379–383 DOI: 10.1243/0954406011520779.
5.
BenjaminS. F.ZhaoH.Arias-GarciaA., Predicting the flow field inside a close-coupled catalyst-the effect of entrance lossesProc. IMechE, Part C: J. Mechanical Engineering Science217 C3 (2003): 283–288 DOI: 10.1243/095440603762870036.
6.
KüchemannD.WeberJ., Aerodynamics of propulsion (New York: McGraw-Hill1953).
7.
MooreF. K.TorrenceK. E., ‘Air flow in dry natural-drought cooling towers subject to wind’ 1977) Cornell Energy multiple-tube systems, Cornell Energy Report, Ithaca, New York.
8.
MohandesM. A.JonesT. V.RussellC. M. B., ‘Pressure loss mechanisms in resistances inclined to an air flow with application to fin tubes’ (In Proceedings of the First National Heat Transfer Conference, Leeds, 1984).
PersoonsT.VanierschotM.Van den BulckE., Oblique inlet pressure loss for swirling flow entering a catalyst substrateExpl. Therm. Fluid Sci.32 (2008): 1223–1231.
11.
ShahR. K., A correlation for laminar hydrodynamic entry length solutions for circular and noncircular ductsTrans. ASME, J. Fluids Eng.100 (1978): 177–179.
12.
WendlandD. W.SorellP. L.KreucherJ. E., ‘Sources of monolith catalytic converter pressure loss’ (1991): SAE paper 912372.
13.
QuadriS. S., The effect of oblique entry flow in automotive catalytic converters (2008) PhD Thesis.
14.
Star-CD user guide, version 3.26, 2005 (CD-Adapco).
15.
IaccarinoG., Predictions of a turbulent separated flow using commercial CFD codesTrans. ASME, J. Fluids Eng.123 (2001): 819–828.
