Flow Structures and Losses in the Exhaust Port of an Internal Combustion Engine

Wang, Yue; Semlitsch, Bernhard; Mihăescu, Mihai; Fuchs, László

doi:10.1115/imece2013-64610

Cited by 3 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the upper side of the valve, two lobes bend with the annular jet into the exhaust pipe, which originate from the outer edges of the valve. These large scale vortical structures have also been noted by Wang et al [30] and the structures have been shown on a cut plane in terms of the streamwise vorticity. These structures can be considered as Deanlike vortices [33], which are induced due to the bending of the L valve port.…”

Section: Static Mass Flow Rate Inletsupporting

confidence: 73%

“…3. A grid sensitivity study for this kind of case setup and a comparison to experimental data has been presented previously [30]. The grid sensitivity study revealed that minor differences occur in the velocity and turbulence kinetic energy line plots.…”

Section: Numerical Mesh-gridmentioning

confidence: 95%

“…At the valve head, Görtlerlike vortical structures form due to the contracting jet streams and therefore, the jets do not remain attached to the valve head surfaces. A small wake forms in this region behind the valve stems close to the top wall and vortex shading takes place [30]. Further downstream, the flow follows the shape of the wall into the exit pipe.…”

Section: Constant Mass Flow Rate Casementioning

confidence: 99%

“…At the pulse peak, the velocity magnitudes in the exhaust port can reach up to 145 m/s, whereas for the constant mass flow rates, the velocity magnitudes in the exhaust port stay below 130 m/s. The components of total pressure losses have been investigated by Wang et al [30]. Kinetic energy losses in the exhaust port scale quadratically with the velocity magnitude in the exhaust port.…”

Section: Pulsating Mass Flow Rate Casementioning

confidence: 99%

“…With that the low momentum stream from valve port L flows towards the low pressure region generated. This induces a strong swirling motion in the exhaust pipe [30]. Due to the change of the low static pressure zone with flow pulsation, the swirling motion in the exhaust pipe is influenced.…”

Section: Pulsating Mass Flow Rate Casementioning

confidence: 99%

See 4 more Smart Citations

Flow effects due to pulsation in an internal combustion engine exhaust port

Semlitsch¹,

Wang²,

Mihăescu³

2014

Energy Conversion and Management

Self Cite

View full text Add to dashboard Cite

In an internal combustion engine, the residual energy remaining after combustion in the exhaust gasses can be partially recovered by a downstream arranged device. The exhaust port represents the passage guiding the exhaust gasses from the combustion chamber to the energy recovering device, e.g. a turbocharger. Thus, energy losses in the course of transmission shall be reduced as much as possible. However, in one-dimensional engine models used for engine design, the exhaust port is reduced to its discharge coefficient, which is commonly measured under constant inflow conditions neglecting engine-like flow pulsation. In this present study, the influence of different boundary conditions on the energy losses and flow development during the exhaust stroke are analyzed numerically regarding two cases, i.e. using simple constant and pulsating boundary conditions. The compressible flow in an exhaust port geometry of a truck engine is investigated using three-dimensional Large Eddy Simulations (LES). The results contrast the importance of applying engine-like boundary conditions in order to estimate accurately the flow induced losses and the discharge coefficient of the exhaust port. The instantaneous flow field alters significantly when pulsating boundary conditions are applied. Thus, the induced losses by the unsteady flow motion and the secondary flow motion are increased with inflow pulsations. The discharge coefficient decreased about 2% with flow pulsation. A modal flow decomposition method, i.e. Proper Orthogonal Decomposition (POD), is used to analyze the coherent structures induced with the particular inflow and outflow conditions. The differences in the flow field for different boundary conditions suggest to incorporate a modeling parameter accounting for the quality of the flow at the turbocharger turbine inlet in one-dimensional simulations.

show abstract

Section: Static Mass Flow Rate Inletsupporting

confidence: 73%

Section: Numerical Mesh-gridmentioning

confidence: 95%

Section: Constant Mass Flow Rate Casementioning

confidence: 99%

Section: Pulsating Mass Flow Rate Casementioning

confidence: 99%

Section: Pulsating Mass Flow Rate Casementioning

confidence: 99%

See 3 more Smart Citations

Flow effects due to pulsation in an internal combustion engine exhaust port

Semlitsch¹,

Wang²,

Mihăescu³

2014

Energy Conversion and Management

Self Cite

View full text Add to dashboard Cite

show abstract

An approach for the thermal analysis of internal combustion engines’ exhaust valves

Cerdoun

Carcasci

Ghenaiet

2016

Applied Thermal Engineering

View full text Add to dashboard Cite

Influences of the dead end on the flow characteristics at the exhaust manifold of a marine diesel engine

Benek

Özsoysal

2021

Journal of Thermal Engineering

View full text Add to dashboard Cite

A 3D Computational Fluid Dynamics (CFD) model of an exhaust manifold with and without a dead end has been developed to investigate the impacts of its geometry on the flow structure and the pressure distribution within the manifold. The model differs from previously studied models principally for its ability to approach the realistic operating principle of an engine as the modelled exhaust valves of the investigated engine open and close according to the firing order. The experimental results of an exhaust manifold without a dead end has been used to validate the CFD model through the pressure distribution and the flow structure. The outcomes demonstrated that the developed CFD model concurred well with the experimental data. The effects of the dead end on the exhaust manifold were then investigated using the validated CFD model. The study has revealed that the addition of a dead end (i) provides a smoother pressure distribution inside the manifold and increase in the efficiency of the turbocharger and (ii) decreases the pressure inside of the interconnection pipes of cylinders while the exhaust gas discharges. Moreover, the results disclose a smoother discharge of exhaust gases leading to a more effective sweeping of the exhaust gas thorough the cylinder without causing any exhaust backpressure. Furthermore, the dead end reduces the turbulence kinetic energy at the blind end of the exhaust manifold resulting in a decrease of pressure loss within. The abovementioned findings regarding to the flow structure and the pressure distribution within the exhaust manifold improve the efficiency of the engine.Cite this article as: Gorkem B, Osman A. Influences of the dead end on the flow characteristics at the exhaust manifold of a marine diesel engine.

show abstract

Flow Structures and Losses in the Exhaust Port of an Internal Combustion Engine

Cited by 3 publications

References 10 publications

Flow effects due to pulsation in an internal combustion engine exhaust port

Flow effects due to pulsation in an internal combustion engine exhaust port

An approach for the thermal analysis of internal combustion engines’ exhaust valves

Influences of the dead end on the flow characteristics at the exhaust manifold of a marine diesel engine

Contact Info

Product

Resources

About