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| 2. |
- Jedrzejowski, Stanislaw, et al.
(författare)
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Determination of a Heat Transfer Between Injected Diesel Fuel and a Temperature Controlled Wall
- 2006
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Ingår i: Journal of KONES Powertrain and Transport. ; 13, s. 179-185
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The paper presents results of the experimental determination of heat fluxes between diesel fuel jet and a steel wall. The experiments were performed in the high pressure and temperature rig at the Chalmers University. Theexperimental stand allowed setting the pressures and the temperatures in the chamber similar to the conditions in adiesel engine during the compression stroke. A standard common rail injecting system and an injector with a singlehole nozzle were used. The measurements were taken for different pressures/temperature combinations. However, inrespect to have similar jet formation conditions and fuel droplets penetration range, the air density in the chamberwas kept on constant level.The temperature-controlled wall was mounted perpendicular to the fuel jet. The wall was equipped with coaxialthermocouples for recording the surface temperatures. The thermocouples had very thin vacuum deposited junctionsthat offered very fast response. The recorded time histories of the surface temperatures were used to calculate the local heat fluxes on a basis of the one-dimensional transient heat conduction model.The experimental chamber had an optical access allowing observing the jet and the swirl formation when the fuelreached the wall. A high-speed camera was used to record the jet behaviour.
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| 3. |
- Magnusson, Alf, 1958, et al.
(författare)
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A Comparison of Heat Transfer and Spray Characteristics for a Model Fuel and Standard Diesel Interacting with a Temperature-Controlled Wall
- 2006
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Ingår i: Thiesel 2006. - 8497059824
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Konferensbidrag (refereegranskat)abstract
- The objective of this work is to compare the heat transfer and liquid penetration of two different diesel fuels when they impinge on a temperature-controlled wall. The study was performed in a high pressure, high temperature spray rig at conditions corresponding to a direct injected diesel engine. Two fuels were used in this study, a standard diesel fuel and a two-component model fuel.The temperature-controlled wall on which the fuel impinged was mounted at different distances downstream of the nozzle in the spray chamber. It was equipped with four coaxialthermocouples for recording the surface temperature. The thermocouples had a vacuum deposited junction that offered a response time of approximately \unit{3}{\micro\second}.Recorded time histories of the surface temperatures showed that the two fuels have a similar heat transfer at two different wall temperatures. It could also be seen that walland air temperature had a great influence on the heat transfer.The spray characteristics were measured with a Phase Doppler Particle Analyzer and high speed imaging. Image analysis showed that the two fuels have a similar penetration even though both methods showed that the model fuel, Idea, evaporates faster. PDPA data show that the axial mean velocity behaves the same close to the spray centre but changes further out. The radial (mode) velocities are mainly dependant on height position for both fuels. The droplet diameter is larger for the diesel fuel at all positions, probably because of a stronger evaporation of the model fuel.
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| 4. |
- Magnusson, Alf, 1958, et al.
(författare)
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Spray-wall interaction: an experimental study of multiple injections of standard diesel
- 2005
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Ingår i: Ilass Europe 2005. ; , s. 425-429
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Spray-wall phenomena were investigated in a high-pressure/high-temperature spray rig with optical access. The spray impinged on a tempered wall 32 mm downstream of the nozzle tip. The properties that were studied were axial and radial penetration, and heat transferred between the fuel and the wall, and how these were influenced by fuel pressure, air density and wall temperature. The injection was split into two and the behaviour of the two injections was compared.
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| 5. |
- Magnusson, Alf, 1958, et al.
(författare)
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Spray-wall interaction: Diesel fuels impinging on a tempered wall
- 2006
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Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627.
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Tidskriftsartikel (refereegranskat)abstract
- Heat transfer from impinging sprays in direct injected diesel engines has been found to influence the rate of heat release and the formation of emissions. The use of multiple injections may also affect heat transfer. The objective of this work is to study heat transfer between the wall and the spray, and how the surface temperature of the wall affects spray behaviour in single and split injections. Two different diesel fuels were used in the experiments, noteworthy is that the diesel fuel had a higher radial penetration rate than the Idea fuel at evaporating conditions but not at non-evaporating conditions. The walltemperature has no measurable influence on radial penetration but does have a significant influence on the heat transfer.
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| 6. |
- Montorsi, Luca, 1972, et al.
(författare)
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Numerical and experimental analysis of the wall film thickness for diesel fuel sprays impinging on a temperature-controlled wall
- 2007
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Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627.
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Konferensbidrag (refereegranskat)abstract
- Analysis of spray-wall interaction is a major issue in the study of the combustion process in DI diesel engines. Along with spray characteristics, the investigation of impinging sprays and of liquid wall film development is fundamental for predicting the mixture formation. Simulations of these phenomena for diesel sprays need to be validated and improved; nevertheless they can extend and complement experimental measurements. In this paper the wall film thickness for impinging sprays was investigated by evaluating the heat transfer across a temperature-controlled wall. In fact, heat transfer is significantly affected by the wall film thickness, and both experiments and simulations were carried out to correlate the wall temperature variations and film height.The numerical simulations were carried out using the STAR-CD and the KIVA-3V, rel. 2, codes. Different wall impingement models and liquid film approaches were analyzed and numerical results were compared with measurements available in the literature and with experiments carried out at Chalmers. The conditions for which the simulations were performed correspond to those found during the compression stroke in a diesel engine. The fuel used was a 2-component model fuel (Idea, 70% n-decane and 30% α methylnaphthalene).The experiments were carried out in the Chalmers high-pressure/high-temperature spray rig for non-evaporating and evaporating conditions. The spray chamber was equipped with a temperature-controlled wall, including coaxial thermocouples for recording the surface temperature. The time histories of the surface temperatures were used to calculate the local heat fluxes applying a 1-dimensional transient heat conduction model.
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