Characterization of Flow Produced by a High-Swirl Inlet Port

Uzkan, Teoman; Borgnakke, Claus; Morel, Thomas

doi:10.4271/830266

Cited by 41 publications

(11 citation statements)

References 12 publications

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“…Coefficient of variation (COV) in indicated mean effective pressure (IMEP) is calculated from measured incylinder pressures as IMEP IMEP COV 100% IMEP (10) to characterize the cyclic variation, with IMEP IMEP and being the mean and standard deviation for 256 consecutive cycles, respectively. Lowest normalized value (LNV) in IMEP defined as lowest IMEP IMEP LNV 100%, IMEP (11) is another useful parameter to quantify combustion instability, where IMEP lowest designates the lowest IMEP for 256 cycles. Lower LNV would usually suggest a less stable combustion.…”

Section: Discussionmentioning

confidence: 99%

“…The steady flow testing of cylinder head is a common practice in engine development to quantify the breathing capacity and in-cylinder charge motion. To capture swirl, typically paddle wheels and flow torque meters are used, hence the calculated swirl ratio can reflect the mixture motion under the corresponding engine operating conditions [11,12]. To measure tumble characteristics, on the other hand, different approaches have been developed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Impact of Tumble on Combustion in SI Engines: Correlation between Flow and Engine Experiments

He¹,

Selamet²,

Reese³

et al. 2007

SAE Technical Paper Series

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The introduction of tumble into the combustion chamber is an effective method of enhancing turbulence intensity prior to ignition, thereby accelerating the burn rates, stabilizing the combustion, and extending the dilution limit. In this study, the primary intake runners are partially blocked to produce different levels of tumble motion in the cylinder during the air induction process. Experiments have been performed with a Chrysler 2.4L 4-valve I4 engine at maximum brake torque timing under two operating conditions: 2.41 bar brake mean effective pressure (BMEP) at 1600 rpm, and 0.78 bar BMEP at 1200 rpm. A method has been developed to quantify the tumble characteristics of blockages under steady flow conditions in a flow laboratory, by using the same cylinder head, intake manifold, and tumble blockages from the engine experiments. A refined tumblemeter is installed under cylinder head to measure the compressive load of the tumble vortex, allowing for the calculation of angular momentum of the incoming air, tumble number, and tumble ratio at varying intake valve lifts. A correlation is then sought between the engine and flow experiments to help quantify the impact of tumble motion on combustion and cyclic variation. The air flow rate into the cylinder, discharge coefficient of the intake system, and the flow loss coefficient across the blockage are also analyzed for different levels of tumble motion. The validity of the method under steady flow conditions is confirmed by comparison of the results with the engine experiments.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Impact of Tumble on Combustion in SI Engines: Correlation between Flow and Engine Experiments

He¹,

Selamet²,

Reese³

et al. 2007

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…However, a great deal of information can be deduced about the running engine by using a test rig in which the relationship between ow and pressure drop is studied for xed con gurations, such as constant valve lift and piston position for a steady ow. 14 By running a steady-state analysis we may obtain performance measures akin to those achieved experimentally. For this study we use a geometry that has a xed valve lift and xed piston.…”

Section: Cfd Analysis Of Swirl Portsmentioning

confidence: 98%

Partial Differential Equation Surface Generation and Functional Shape Optimization of a Swirl Port

Dekanski

Bloor

Wilson

1997

Journal of Propulsion and Power

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In this paper we demonstrate how a novel approach to surface design may be used for the representation of a generic swirl port geometry. The advantage of this methodology, referred to as the partial differential equation (PDE) method, lies in the rapid generation and speed of alteration of geometries, coupled with the fact that a small parameter set controls the geometry. In the rst part of the paper, we illustrate how a generic swirl port may be generated, which, when analyzed using computational uid dynamics (CFD) techniques, is shown to give performance characteristics similar to the geometries of existing designs. In the second part of the paper we discuss performance characteristics, in particular we deal with the swirl generated in the ow. We discuss how steady-state CFD calculations may be used to calculate established rule-of-thumb performance measures and illustrate how the PDE geometry may be easily manipulated to show the impact the geometry has on the performance measures. Finally, we demonstrate the bene ts of using the PDE method for functional design, speci cally how the control of the swirl port geometry with a small number of parameters enables us to use numerical optimization to obtain an improved performance measure by altering the surface geometry.

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“…How GT-POWER calculates the above-mentioned in-cylinder flow can be seen in [13], [14] and [15]. In GT-POWER, the swirl, tumble and NTI can be plotted as a function of CAD.…”

Section: Calculations Of Swirl and Tumblementioning

confidence: 99%

Optical Study of Swirl during Combustion in a CI Engine with Different Injection Pressures and Swirl Ratios Compared with Calculations

Dembinski¹,

Ångström²

2012

SAE Technical Paper Series

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Spray and mixture formation in a compression-ignition engine is of paramount importance in the diesel combustion process. In an engine transient, when the load increases rapidly, the combustion system needs to handle low λ operation without producing high NO x emissions and large amounts of particulate matter. By changing the in-cylinder flow, the emissions and engine efficiency are affected. Optical engine studies were therefore performed on a heavy-duty engine geometry at different fuel injection pressures and inlet airflow characteristics. By applying different inlet port designs and valve seat masking, swirl and tumble were varied. In the engine tests, swirl number was varied from 2.3 to 6.3 and the injection pressure from 500 to 2500 bar. To measure the in-cylinder flow around TDC, particle image velocimetry software was used to evaluate combustion pictures. The pictures were taken in an optical engine using a digital high-speed camera. Clouds of glowing soot particles were captured by the camera and traced with particle image velocimetry software. The velocity-vector field from the pictures was thereby extracted and a mean swirl number was calculated. The swirl number was then compared with 1D simulation program GT-POWER and CFD based correlations. The GT-POWER simulations and CFD based correlation calculations were initiated from steady-state flow bench data on tested cylinder heads.The main conclusions from this study were that the mean swirl numbers, evaluated with the PIV software from combustion pictures around TDC, agreed with CFD based correlations and the low swirl numbers also correlated with the 1D-simulation program. Most of the induced swirl motion survives the compression and combustion, while the induced tumble does not survive to the late combustion phase. The tumble however, disturbs the swirl motion and offsets the swirl centre. This offset survives the compression and combustion. The diesel sprays that are injected symmetrically in the combustion chamber are thereby exposed to the swirl asymmetrically. This study also shows that the angular velocity at different piston bowl radii deviates from solid body rotation. The angular velocity is higher closer to the centre and decreases to be at the lowest value at the outer piston bowl edge. When the injection pressure is increased, the deviation from solid body rotation increases due to spray effects.

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Characterization of Flow Produced by a High-Swirl Inlet Port

Cited by 41 publications

References 12 publications

Impact of Tumble on Combustion in SI Engines: Correlation between Flow and Engine Experiments

Impact of Tumble on Combustion in SI Engines: Correlation between Flow and Engine Experiments

Partial Differential Equation Surface Generation and Functional Shape Optimization of a Swirl Port

Optical Study of Swirl during Combustion in a CI Engine with Different Injection Pressures and Swirl Ratios Compared with Calculations

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