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Combining instantaneous temperature measurements and CFD for analysis of fuel impingement on the DISI engine piston top / Kukwon Cho in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 7 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 7 (Juillet 2010) . - 09 p. Titre : Combining instantaneous temperature measurements and CFD for analysis of fuel impingement on the DISI engine piston top Type de document : texte imprimé Auteurs : Kukwon Cho, Auteur ; Ronald O. Grover, Jr., Auteur ; Dennis Assanis, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Computational  fluid  dynamics  Heat  measurement  Pistons  Thermocouples Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A two-pronged experimental and computational study was conducted to explore the formation, transport, and vaporization of a wall film located at the piston surface within a four-valve, pent-roof, direct-injection spark-ignition engine, with the fuel injector located between the two intake valves. Negative temperature swings were observed at three piston locations during early injection, thus confirming the ability of fast-response thermocouples to capture the effects of impingement and heat loss associated with fuel film evaporation. Computational fluid dynamics (CFD) simulation results indicated that the fuel film evaporation process is extremely fast under conditions present during intake. Hence, the heat loss measured on the surface can be directly tied to the heating of the fuel film and its complete evaporation, with the wetted area estimated based on CFD predictions. This finding is critical for estimating the local fuel film thickness from measured heat loss. The simulated fuel film thickness and transport corroborated well temporally and spatially with measurements at thermocouple locations directly in the path of the spray, thus validating the spray and impingement models. Under the strategies tested, up to 23% of fuel injected impinges upon the piston and creates a fuel film with thickness of up to 1.2 µm. In summary, the study demonstrates the usefulness of heat flux measurements to quantitatively characterize the fuel film on the piston top and allows for validation of the CFD code. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000007 [...] [article] Combining instantaneous temperature measurements and CFD for analysis of fuel impingement on the DISI engine piston top [texte imprimé] / Kukwon Cho, Auteur ; Ronald O. Grover, Jr., Auteur ; Dennis Assanis, Auteur . - 2011 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 7 (Juillet 2010) . - 09 p. Mots-clés : Computational  fluid  dynamics  Heat  measurement  Pistons  Thermocouples Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A two-pronged experimental and computational study was conducted to explore the formation, transport, and vaporization of a wall film located at the piston surface within a four-valve, pent-roof, direct-injection spark-ignition engine, with the fuel injector located between the two intake valves. Negative temperature swings were observed at three piston locations during early injection, thus confirming the ability of fast-response thermocouples to capture the effects of impingement and heat loss associated with fuel film evaporation. Computational fluid dynamics (CFD) simulation results indicated that the fuel film evaporation process is extremely fast under conditions present during intake. Hence, the heat loss measured on the surface can be directly tied to the heating of the fuel film and its complete evaporation, with the wetted area estimated based on CFD predictions. This finding is critical for estimating the local fuel film thickness from measured heat loss. The simulated fuel film thickness and transport corroborated well temporally and spatially with measurements at thermocouple locations directly in the path of the spray, thus validating the spray and impingement models. Under the strategies tested, up to 23% of fuel injected impinges upon the piston and creates a fuel film with thickness of up to 1.2 µm. In summary, the study demonstrates the usefulness of heat flux measurements to quantitatively characterize the fuel film on the piston top and allows for validation of the CFD code. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000007 [...]