Development of a high-speed UV particle image velocimetry technique and application for measurements in internal combustion engines

Fajardo, Claudia M.; Sick, Volker

doi:10.1007/s00348-008-0535-z

Cited by 36 publications

(13 citation statements)

References 39 publications

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“…For the swirl view measurements, the Laser beam was converted to a sheet of about 0.5-1 mm thickness by a combination of spherical and cylindrical lenses, fired horizontally through the pentroof of the engine in full optical setup (quartz liner and sapphire piston window); the camera was positioned in front of the 45° mirror that was situated within the Bowditch piston arrangement, see Figure 2 Several aspects of the PIV technique, including practical application, precision and uncertainties were optimised according to [23] in consultation with seminal publications on the specifics of PIV [24][25][26][27][28][29][30][31] and previously published PIV studies focused on internal combustion engine measurements [6][7][8][9][32][33][34]. In this context, Table 3 summarises the system's main settings and several other details of the PIV measurements presented in this paper, e.g.…”

Section: Test Procedures Pivmentioning

confidence: 99%

Modulation of integral length scales of turbulence in an optical SI engine by direct injection of gasoline, iso -octane, ethanol and butanol fuels

Aleiferis

Behringer

2017

Fuel

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In-cylinder air flow structures are known to play a major role in mixture preparation and engine operating limits for spark-ignition engines. In this paper PIV measurements were undertaken in an optical spark-ignition at 1500 RPM, part-load with 0.5 bar intake plenum pressure. One of the PIV planes was vertical, cutting through the centrally located spark plug (tumble plane). The other plane was horizontal 1 mm below the spark plug ground electrode (swirl plane). The effect of engine head temperature was also examined by using engine-head coolant temperatures of 20 °C and 80 °C. The flow field was examined late in the compression stroke at typical ignition timing. The study was conducted under air-only motoring engine conditions but also under fuelled conditions in the early intake stroke using direct injection of gasoline, iso-octane, ethanol and butanol fuels. The flow field under air-only motored conditions showed velocities between 3-5 m/s predominantly from intake to exhaust. Little differences were observed between hot and cold engine-head temperature; typically ~10% larger mean velocity and turbulent kinetic energy was seen on the intake side. Integral length scales were on the tumble plane between 2-4.5 mm in the vertical and 4-7 mm in the horizontal direction. The swirl view showed scales between 4-10 mm, larger at cold than at hot engine-head conditions. The vertical length scales appeared to be limited by the clearance height, scaling typically by about 10-15%. The horizontal components scaled to the cylinder bore diameter by about 5-12%. The fuel injection process in the early intake stroke led to little differences in the general mean flow structure at ignition timing, except for a small increase in the maximum velocities, ~10%. The turbulent kinetic on the tumble plane was highest towards the exhaust side of the engine under non-fuelled engine conditions but fuel injection resulted in highest values on the intake side. The integral length scales with fuel injection were of the same order of magnitude to those of air only measurements on the tumble plane, but showed distinctly larger areas with length scales up to 9 mm on the swirl plane. Differences between fuels for their fuel specific injection duration were small, with average length scales between 4-6 mm. Ethanol exhibited typically largest scales and butanol smallest.3

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Section: Test Procedures Pivmentioning

confidence: 99%

Modulation of integral length scales of turbulence in an optical SI engine by direct injection of gasoline, iso -octane, ethanol and butanol fuels

Aleiferis

Behringer

2017

Fuel

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“…In configurations with low throughplane motion, such diagnostics have the capability of explicitly resolving important dynamic processes [51][52][53][54][55][56][57]. High-repetitionrate diagnostics also have been applied to study swirl-stabilized flames in gas-turbine-like combustors [50,58].…”

Section: Introductionmentioning

confidence: 99%

Flow–flame interactions causing acoustically coupled heat release fluctuations in a thermo-acoustically unstable gas turbine model combustor

Steinberg

Boxx

Stöhr

et al. 2010

Combustion and Flame

271

149

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a b s t r a c tA detailed analysis of the flow-flame interactions associated with acoustically coupled heat-release rate fluctuations was performed for a 10 kW, CH 4 /air, swirl stabilized flame in a gas turbine model combustor exhibiting self-excited thermo-acoustic oscillations at 308 Hz. High-speed stereoscopic particle image velocimetry, OH planar laser induced fluorescence, and OH* chemiluminescence measurements were performed at a sustained repetition rate of 5 kHz, which was sufficient to resolve the relevant combustor dynamics. Using spatio-temporal proper orthogonal decomposition, it was found that the flow-field contained several simultaneous periodic motions: the reactant flux into the combustion chamber periodically oscillated at the thermo-acoustic frequency (308 Hz), a helical precessing vortex core (PVC) circumscribed the burner nozzle at 515 Hz, and the PVC underwent axial contraction and extension at the thermo-acoustic frequency. The global heat release rate fluctuated at the thermo-acoustic frequency, while the heat release centroid circumscribed the combustor at the difference between the thermoacoustic and PVC frequencies. Hence, the three-dimensional location of the heat release fluctuations depended on the interaction of the PVC with the flame surface. This motivated the compilation of doubly phase resolved statistics based on the phase of both the acoustic and PVC cycles, which showed highly repeatable periodic flow-flame configurations. These include flames stabilized between the inflow and inner recirculation zone, large-scale flame wrap-up by the PVC, radial deflection of the inflow by the PVC, and combustion in the outer recirculation zones. Large oscillations in the flame surface area were observed at the thermo-accoustic frequency that significantly affected the total heat-release oscillations. By filtering the instantaneous reaction layers at different scales, the importance of the various flow-flame interactions affecting the flame area was determined. The greatest contributor was large-scale elongation of the reaction layers associated with the fluctuating reactant flow rate, which accounted for approximately 50% of the fluctuations. The remaining 50% was distributed between fine scale stochastic corrugation and large-scale corrugation due to the PVC.

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“…Their work depicted that at the lower surrounding pressures, spray angle is directly related to the amount of bio-ethanol in the blend, while spray tip penetration is inversely related to bio-ethanol of blend as well. Fajardo and Sick [10] presented an extension of high speed PIV suitable for high luminous combustion condition of internal combustion engines. They reported the velocity domain at the top dead center in a DI engine with speed of 2000 RPM at the red situation.…”

Section: Introductionmentioning

confidence: 99%

Experimental and theoretical investigation on spray characteristics of bio-ethanol blends using a direct injection system

Ghahremani¹,

Jafari²,

Ahari³

et al. 2017

Scientia Iranica

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Abstract. In the present work, the spray characteristics of bio-ethanol and its blends have been experimentally and theoretically investigated. To have a comprehensive study, the e ects of ambient condition and injection pressure on the spray of di erent blends have been considered. Macroscopic and microscopic characteristics of spray such as tip penetration length, cone angle, projected area, volume, Sauter Mean Diameter (SMD), and Ohnesorge number are investigated precisely. Besides, air entrainment and atomization analyses have been carried out to improve mixture formation process. Using curve tting and least squares method, theoretical correlations have been suggested in such a way to predict experimental results with the accuracy of 9.9%. To have a good estimation of the calculated parameters, uncertainty analysis has been performed. The results demonstrate that enhancing the injection pressure or decreasing the ambient pressure improves the atomization characteristics of spray. Moreover, outcomes of this study indicate that spray tip penetration is enhanced by increasing the injection pressure or bio-ethanol percentage in the blend, while spray cone angle showing the opposite behavior.

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Development of a high-speed UV particle image velocimetry technique and application for measurements in internal combustion engines

Cited by 36 publications

References 39 publications

Modulation of integral length scales of turbulence in an optical SI engine by direct injection of gasoline, iso -octane, ethanol and butanol fuels

Modulation of integral length scales of turbulence in an optical SI engine by direct injection of gasoline, iso -octane, ethanol and butanol fuels

Flow–flame interactions causing acoustically coupled heat release fluctuations in a thermo-acoustically unstable gas turbine model combustor

Experimental and theoretical investigation on spray characteristics of bio-ethanol blends using a direct injection system

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