Unburned gas temperature measurements in a surrogate Diesel jet via two-color toluene-LIF imaging

Tea, Gabrielle; Bruneaux, Gilles; Kashdan, Julian T.; Schulz, Christof

doi:10.1016/j.proci.2010.05.074

Cited by 26 publications

(12 citation statements)

References 17 publications

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“…At each measurement, one of these filters was mounted to the camera lens. For mapping of the images at two different colors, a strategy developed by (Tea et al 2011) was used. The gate width of the camera for both color bands was set to 20 ms.…”

Section: Two-color Pyrometry Imagingmentioning

confidence: 99%

Investigations of the long-term effects of LII on soot and bath gas

Cenker

Bennett

Roberts

2017

Aerosol Science and Technology

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A combination of high-repetition rate imaging, laser extinction measurements, two-color soot pyrometry imaging, and high-resolution transmission electron microscopy of thermophoretically sampled soot is used to investigate the long-term and permanent effects of rapid heating of inflame soot during laser-induced incandescence (LII). Experiments are carried out on a laminar nonpremixed co-annular ethylene/air flame with various laser fluences. The high-repetition rate images clearly show that the heated and the neighboring laser-border zones undergo a permanent transformation after the laser pulse, and advect vertically with the flow while the permanent marking is preserved. The soot volume fraction at the heated zone reduces due to the sublimation of soot and the subsequent enhanced oxidation. At the laser-border zones, however, optical thickness increases that may be due to thermophoretic forces drawing hot particles towards relatively cooler zones and the rapid compression of the bath gas induced by the pressure waves created by the expansion of the desorbed carbon clusters. Additionally sublimed carbon clusters can condense onto existing particles and contribute to increase of the optical thickness. Timeresolved two-color pyrometry imaging show that the increased temperature of soot both in the heated and neighboring laser-border zones persists for several milliseconds. This can be associated to the increase in the bath-gas temperature, and a change in the wavelength-dependent emissivity of soot particles induced by the thermal annealing of soot. Ex-situ analysis show that the lattice structure of the soot sampled at the laser-border zones tend to change and soot becomes more graphitic. This may be attributed to thermal annealing induced by elevated temperature.

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Section: Two-color Pyrometry Imagingmentioning

confidence: 99%

Investigations of the long-term effects of LII on soot and bath gas

Cenker

Bennett

Roberts

2017

Aerosol Science and Technology

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“…To date, investigations of diesel fuel–air mixing processes have mostly used the typical gasoline tracers TOL in a gasoline surrogate fuel blend of nHEP and ISO. 11–13 Surrogate fuels based on these gasoline PRFs do not match the physical properties of diesel very well, so the authors suggest using a blend of nHD and heptamethylnonane (HMN) instead. These diesel PRFs have cetane numbers (CNs) of 100 for nHD and 15 for HMN; hence, every CN in between can be simulated by an appropriate blend.…”

Section: Tracer Selectionmentioning

confidence: 99%

“…1–8 It can be applied with high temporal and spatial resolution to image fuel or exhaust gas recirculation (EGR) distributions as well as temperature inside optically accessible IC engines. Commonly applied tracers are acetone, 3,7 3-pentanone, 9,10 toluene (TOL) 7,11–13 and triethylamine, 8 all of which are used for concentration or fuel/air ratio imaging in gasoline engines. A new technique, which employs 1-methylnaphthalene as a tracer in a mixture of the diesel primary reference fuels (PRFs) n-hexadecane (nHD) (cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane), overcomes the shortcomings of mismatched fuel volatility and density associated with commonly used TOL/n-heptane (nHEP)/iso-octane (ISO) PLIF techniques 11–13 for measurements in diesel engines.…”

Section: Introductionmentioning

confidence: 99%

“…Commonly applied tracers are acetone, 3,7 3-pentanone, 9,10 toluene (TOL) 7,11–13 and triethylamine, 8 all of which are used for concentration or fuel/air ratio imaging in gasoline engines. A new technique, which employs 1-methylnaphthalene as a tracer in a mixture of the diesel primary reference fuels (PRFs) n-hexadecane (nHD) (cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane), overcomes the shortcomings of mismatched fuel volatility and density associated with commonly used TOL/n-heptane (nHEP)/iso-octane (ISO) PLIF techniques 11–13 for measurements in diesel engines. Here, this technique has been applied to investigate the influence of pilot injections on mixture formation in a diesel engine.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fuel concentration imaging inside an optically accessible diesel engine using 1-methylnaphthalene planar laser-induced fluorescence

Trost

Zigan

Leipertz

et al. 2014

International Journal of Engine Research

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The performance and emissions of modern automotive diesel engines are highly dependent on the application of pilot injection technology. This technology also appears well suited for application to low-temperature combustion strategies. In this study, the first results of a new quantitative planar laser-induced fluorescence equivalence ratio measurement technique of pilot injections inside an optically accessible diesel engine are presented using 1-methylnaphthalene as a tracer in a mixture of the diesel primary reference fuels, n-hexadecane (cetane) and 2,2,4, 4,6,8,8-heptamethylnonane (isocetane). This combination overcomes the shortcomings of mismatched fuel volatility and density associated with commonly used toluene/n-heptane/iso-octane planar laser-induced fluorescence techniques. A tracer characterization in a flow cell and a calibration in the internal combustion engine are performed. The internal combustion engine measurements illustrate the mixture formation process for a pilot injection. Even at low injection mass of 3 mg, a strong penetration of the pilot is observed; fuel hits the piston bowl wall and is redirected upward to the cylinder head. Small amounts of fuel are also found to have penetrated into the bottom of the piston bowl. At top dead center, the pilot injection is still not completely homogeneously distributed in the piston bowl, and local equivalence ratios of F . 1 are found in the bowl.

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“…The study emphasized the importance of multicomponent evaporation models which include mixing within the droplets to properly predict the spray behavior at high pressure conditions. Twocolor toluene LIF was utilized by Tea et al [30] to obtain temperature measurements of the unburned fuel/air mixture in diesel sprays which can be used to infer the vapor phase distribution. However, this technique has some limitations at temperatures above 700 K. Trost et al [31] recently used 1-methylnaphthalene planar laserinduced fluorescence (PLIF) to study fuel concentration for pilot injections of diesel primary reference fuels cetane and iso-cetane in an optically accessible diesel engine.…”

Section: Introductionmentioning

confidence: 99%

Large eddy simulations of complex multicomponent diesel fuels in high temperature and pressure turbulent flows

Srivastava

Jaberi

2017

International Journal of Heat and Mass Transfer

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A multicomponent droplet evaporation model, which discretizes the one-dimensional species and temperature profiles inside a droplet with a finite volume method and treats the liquid phase as thermodynamically real, has been developed and used for large-eddy simulations of high speed diesel sprays in high temperature and pressure closed chambers. Single drop evaporation results obtained by the variable property multicomponent model are shown to match with the constant property model in the limiting conditions. The multicomponent liquid model used together with the Kelvin-Helmholtz-Rayleigh-Taylor droplet breakup model is found to reasonably well predict the experimentally observed non-linear behavior of spray penetration with changing ambient conditions for n-hexadecane and 4 different multicomponent surrogate diesel fuels with 2-8 components. The effects of various modeling assumptions and gas and liquid parameters on the drop and spray evolution and evaporation are investigated in details.

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Unburned gas temperature measurements in a surrogate Diesel jet via two-color toluene-LIF imaging

Cited by 26 publications

References 17 publications

Investigations of the long-term effects of LII on soot and bath gas

Investigations of the long-term effects of LII on soot and bath gas

Fuel concentration imaging inside an optically accessible diesel engine using 1-methylnaphthalene planar laser-induced fluorescence

Large eddy simulations of complex multicomponent diesel fuels in high temperature and pressure turbulent flows

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