The Measurement and Analysis of Swirl in Steady Flow

Stone, C. R.; Ladommatos, Nicos

doi:10.4271/921642

Cited by 47 publications

(33 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Meanwhile, the discharge coefficient with different MVL was measured for have further understanding to the effects of reduced MVL on volumetric efficiency. The measurement was conducted on a steady flow test rig which is based on the principle originally suggested by Ricardo Consulting Engineers [25,26]. In Fig.…”

Section: Optical Engine and Test Conditionsmentioning

confidence: 99%

“…However, under some conditions, it increases the possibility of cycle-to-cycle variation [21][22][23][24]. In an initial measurement by authors on steady flow test rig which is based on the principle originally suggested by Ricardo Consulting Engineers [25,26], results (as shown in Fig. 1) have demonstrated that reduced MVL With those complicated influences of VVL on in-cylinder flow, it will be necessary to explore the detail how air-fuel mixing and combustion would be affected under those conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Investigation into In-Cylinder Tumble Flow Characteristics with Variable Valve Lift in a Gasoline Engine

Wang

Liu

Tan

et al. 2014

Flow Turbulence Combust

View full text Add to dashboard Cite

In this paper, the investigation into in-cylinder tumble flow characteristics with reduced Maximum Valve Lifts (MVL) is presented. The experimental work was conducted in a modified four-valve Spark-Ignition (SI) test engine, with optical accesses for measuring in-cylinder air motion in the vertical direction. Three different MVL of 6.8 mm, 4.0 mm and 1.7 mm were tested and Particle Image Velocimetry (PIV) was employed for those measurements. Measurement results were analysed by examining the tumble flow field, the tumble ratio variation and the fluctuating kinetic energy distribution. Meanwhile, a numerical analysis method for detecting the vortex centre was developed. From results of the vortex centre distribution, the cyclic variation of the in-cylinder flow was explored. The phase-averaged flow fields show that higher MVLs could produce stronger vertical flows which turn more toward to the piston top and finally are possible to form big scale tumble flow structure. Although lower MVLs create a higher tumble ratio when the piston is close to the Bottom Dead Centre (BDC), higher MVLs substantially produce higher tumble ratios when the piston is moving close to the Top Dead Centre (TDC). In terms of kinetic energy, lower MVLs result in higher values including higher total kinetic energy and higher fluctuating energy. Finally, the vortex centres results demonstrate lower MVLs could enhance cycle-to-cycle variation due to the weakened tumble vortex.

show abstract

Section: Optical Engine and Test Conditionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Investigation into In-Cylinder Tumble Flow Characteristics with Variable Valve Lift in a Gasoline Engine

Wang

Liu

Tan

et al. 2014

Flow Turbulence Combust

View full text Add to dashboard Cite

show abstract

“…In this paper, the AVL method [17][18], was used to evaluate the performance of intake port. Although several parameter was acquired during the tests, only the swirl number will be presented in this paper, since the goal is to compare the results of a complete cylinder head vs. intake ports produced via AM (3D printing).…”

Section: In-cylinder Flow Measurementsmentioning

confidence: 99%

“…The swirl coefficient, , is a ratio obtained from the angular momentum measured by the honeycomb at each valve lift, is defined as [17][18]:…”

Section: In-cylinder Flow Measurementsmentioning

confidence: 99%

Swirl Number Measurements Using Intake Ports Produced by Additive Manufacturing

Martioli¹,

Massarani²

2017

Blucher Engineering Proceedings

View full text Add to dashboard Cite

The present work proposes to execute bench test swirl number measurements using a modular device and cylinder head intake ports from a diesel engine manufactured via additive manufacturing (AM). Swirl number measurements with intake ports produced by AM, bring the following advantages: Tests reproducibility, since having the geometric model (CAD) of tested models is enough to re-build the geometry analyzed in the bench test. Easy to measure the swirl number variances in consequence of potential manufacturing process deviations and time reduction to the development of new intake ports geometry. The research is experimental, one sample of the investigated cylinder head was sent to the Polytechnic School of Sao Paulo (EPUSP) laboratory, and the swirl number was measured and recorded for later results comparison with proposed method. This cylinder head sample was then sectioned and digitalized as to know to have the same internal geometry in the intake ports produced via AM. All tests were performed in the same rig and with the same control system aiming to reduce the external variables during data acquisition. When the swirl number results between the complete cylinder head and modular device using AM were compared, no statistically significant changes were found.

show abstract

“…By measuring the torque on the honeycomb at different valve lifts and constant pressure drop over the valves of 25 mbar, the resulting SN was calculated both in GT-POWER and by the Thien method [12]. Tumble was measured in the same rig, but the cylinder head was mounted on a liner with a 90 degree L-type adaptor to enable tumble measurement in the swirl rig (see [13]). Swirl and tumble were measured separately and together for both inlet valves.…”

Section: Steady State Flow Rigmentioning

confidence: 99%

An Experimental Study of the Influence of Variable In-Cylinder Flow, Caused by Active Valve Train, on Combustion and Emissions in a Diesel Engine at Low Lambda Operation

Dembinski¹,

Ångström²

2011

SAE Technical Paper Series

View full text Add to dashboard Cite

Spray and mixture formation in a compression ignition engine is of paramount importance for diesel combustion. In engine transient operation, when the load increases rapidly, the combustion system needs to handle low lambda (λ) operation while avoiding high particle emissions. Single cylinder tests were performed to evaluate the effect of differences in cylinder flow on combustion and emissions at typical low λ transient operation. The tests were performed on a heavy duty single cylinder test engine with Lotus Active Valve Train (AVT) controlling the inlet airflow. The required swirl number (SN) and tumble were controlled by applying different inlet valve profiles and opening either both inlet valves or only one or the other. The operating point of interest was extracted from engine transient conditions before the boost pressure was increased and investigated further at steady state conditions. The AVT enabled the resulting SN to be controlled at bottom dead centre (BDC) from ~0.3 to 6.8 and tumble from ~0.5 to 4. The fuel injection pressure was varied from 500 bar up to 2000 bar, with increments of 500 bar, for each SN and tumble setting. No exhaust gas recirculation was used in following tests. GT-POWER was used to calculate SN, tumble, and turbulent intensity with the different valve settings. The input data for the GT-POWER flow calculations were measured in a steady-state flow rig with honeycomb torque measurement. The main conclusion of this study was that the air flow structure in the cylinder, characterized by SN, tumble, and turbulent intensity, has a significant effect on the resulting engine combustion and emissions for the investigated range of fuel injection pressures. By increasing SN above 3, while maintaining tumble at low levels, the engine could be run with richer air/fuel mixtures without further increasing smoke emissions at injection pressures 1000 bar and above. Also, NOx emissions decreased at λ below 1.3; ignition delay time decreased at higher tumble and turbulent levels; and higher levels of swirl resulted in more rapid combustion, decreasing smoke emissions at injection pressures over 1000 bar. Smoke emissions increase at higher engine speeds (above 1200 rpm) and high SN (above 6). The results of this study demonstrate that the mixing process controlled by in-cylinder flow (swirl and tumble) has a dominant effect on combustion.

show abstract

The Measurement and Analysis of Swirl in Steady Flow

Cited by 47 publications

References 5 publications

An Investigation into In-Cylinder Tumble Flow Characteristics with Variable Valve Lift in a Gasoline Engine

An Investigation into In-Cylinder Tumble Flow Characteristics with Variable Valve Lift in a Gasoline Engine

Swirl Number Measurements Using Intake Ports Produced by Additive Manufacturing

An Experimental Study of the Influence of Variable In-Cylinder Flow, Caused by Active Valve Train, on Combustion and Emissions in a Diesel Engine at Low Lambda Operation

Contact Info

Product

Resources

About