Experimental study of flow dynamics in close-coupled catalyst manifolds

Abstract

Time-resolved flow dynamics in an automotive exhaust manifold with a close-coupled catalyst is investigated experimentally on a charged motored engine (CME) flow rig. Flow similarity between CME and fired engine conditions is discussed analytically. Oscillating hot-wire anemometry (OHW) is used to measure the bidirectional phase-locked velocity. Strong time-resolved mean catalyst velocity fluctuations are observed. These are analysed as Helmholtz resonances, using a one-dimensional gas dynamic model of the manifold. The spatial and temporal occurrence of instantaneous reverse flow in the catalyst are investigated, for varying engine load conditions. Periodic backflow occurs throughout large portions of the catalyst cross-section, and proves to be linked strongly to the observed Helmholtz resonances.

Keywords

exhaust manifold close-coupled catalyst reverse flow Helmholtz resonance oscillating hot-wire anemometry

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References

Persoons

Van den Bulck

Fausto

Study of pulsating flow in close-coupled catalyst manifolds using phase-locked hot-wire anemometry

Exp. Fluids 2004, 36(2), 217–232.

Persoons

Hoefnagels

Van den Bulck

Experimental validation of the addition principle for pulsating flow in close-coupled catalyst manifolds

Trans. ASME J. Fluids Engng 2006, 128(4), 656–670.

Benjamin

S. F.

Roberts

C. A.

Wollin

A study of pulsating flow in automotive catalyst systems

Exp. Fluids 2002, 33(5), 217–232.

Arias-Garcia

Benjamin

S. F.

Zhao

Farr

A comparison of steady, pulsating flow measurements and CFD simulations in close-coupled catalysts

SAE paper 2001-01-3662, 2001.

Liu

Benjamin

S. F.

Roberts

C. A.

Pulsating flow maldistribution within an axisymmetric catalytic converter: Flow rig experiment and transient CFD simulation

SAE paper 2003-01-3070, 2003.

Bressler

Rammoser

Neumaier

Terres

Experimental and predictive investigation of a close-coupled catalyst converter with pulsating flow

SAE paper 960564, 1996.

Hwang

Lee

Mueller

Stuecken

Schock

H. J.

Lee

J. C. T.

Dynamic flow study in a catalytic converter using LDV and high speed flow visualisation

SAE paper 950786, 1995.

Adam

Heinrich

Hopp

Lang

Optimierung von Abgasanlagen mit analytischen Methoden

MTZ 2002, 63(10), 838–846.

Liu

Benjamin

S. F.

Roberts

C. A.

Zhao

Arias-Garcia

A coupled 1D/3D simulation for the flow behaviour inside a close-coupled catalytic converter

SAE paper 2003-01-1875, 2003.

10.

Park

S. B.

Kim

H. S.

Cho

K. M.

Kim

W. T.

An experimental and computational study of flow characteristics in exhaust manifold and CCC (close-coupled catalyst)

SAE paper 980128, 1998.

11.

Benjamin

S. F.

Disdale

Liu

Roberts

C. A.

Zhao

Velocity predictions from a coupled one-dimensional/three-dimensional computational fluid dynamics simulation compared with measurements in the catalyst system of a firing engine

Int. J. Engine Res. 2006, 7(1), 29–40.

12.

Kim

H. S.

Min

Myung

C. L.

Park

A combined experimental and computational approach to improve catalyst flow uniformity and light-off behaviour

Proc. Instn Mech. Engrs, Part D: J. Automobile Engineering 2002, 216(5), 413–430.

13.

Bruun

H. H.

Hot-wire anemometry: Principles and signal analysis, 1995 (Oxford University Press, Oxford).

14.

Thompson

B. E.

Whitelaw

J. H.

Flying hotwire anemometry

Exp. Fluids 1984, 2(1), 47–55.

15.

Persoons

Hoefnagels

Van den Bulck

Calibration of an oscillating hot-wire anemometer for bidirectional velocity measurements

Exp. Fluids 2006, 40(4), 555–567.

16.

Watson

Janota

M. S.

Turbocharging the internal combustion engine, 1982, chapter 15 (MacMillan Press, London).

17.

Weltens

Bressler

Terres

Neumaier

Rammoser

Optimisation of catalytic converter gas flow distribution by CFD prediction

SAE paper 930780, 1993.

18.

Vandevoorde

Vierendeels

Sierens

Dick

A new total variation diminishing scheme for the calculation of one-dimensional flow in inlet and exhaust pipes of internal combustion engines

Proc. Instn Mech. Engrs, Part D: J. Automobile Engineering 1998, 212(5), 437–448.