论文信息 - Transient surface-heat-flux measurements in the exhaust of a SI engine

Transient surface-heat-flux measurements in the exhaust of a SI engine

Surface-heat-flux measurements were performed at two locations in a straight-pipe extension of the exhaust-port of a SI engine. The measured surface-heat-flux history was characterised by a double peak, during the exhaust valve-open period. The largest peak resulted from the action of high-velocity, blowdown gases exiting the combustion chamber at the beginning of the exhaust process. The significantly lower second peak was due to the slower piston-driven gas motion that occurred during the displacement phase. During the closed-valve period, the local surface-heat-flux was found to be relatively low (10-45 kW/m 2 ) in comparison to the peak heat flux (80-288 kW/m 2 ), and to exhibit minimal decay. The predicted heat-flux histories from an engine-simulation analysis, which employed a heat transfer correlation developed by the authors, were in good agreement with the corresponding measured histories during blowdown, however, predictions were relatively poor during the displacement phase, both in magnitude and behaviour.

Mario Farrugia | Alex C. Alkidas | Brian Sangeorzan

[1] Theodor Sams,et al. Heat Transfer to the Combustion Chamber and Port Walls of IC Engines - Measurement and Prediction , 2000 .

[2] A. C. Alkidas,et al. Thermal Studies in the Exhaust System of a Diesel-Powered Light-Duty Vehicle , 2004 .

[3] A. C. Alkidas,et al. Inventory of Heat Losses for a Divided–Chamber Diesel Engine , 1982 .

[4] John B. Heywood,et al. An experimental and analytical study of heat transfer in an engine exhaust port , 1981 .

[5] C. D. Rakopoulos,et al. Experimental instantaneous heat fluxes in the cylinder head and exhaust manifold of an air-cooled diesel engine , 2000 .

[6] S. Sorenson,et al. An Investigation of Instantaneous Heat Transfer Rates in the Exhaust Port of an Internal Combustion Engine , 1981 .

[7] Daniel W. Wendland,et al. Automobile Exhaust-System Steady-State Heat Transfer , 1993 .

[8] Kazuie Nishiwaki,et al. Internal-combustion engine heat transfer , 1987 .

[9] B Lawton. Effect of Compression and Expansion on Instantaneous Heat Transfer in Reciprocating Internal Combustion Engines , 1987 .

[10] A. C. Alkidas,et al. Heat Transfer Characteristics of a Spark-Ignition Engine , 1980 .

[11] Dimitrios T. Hountalas,et al. Measurements and analysis of load and speed effects on the instantaneous wall heat fluxes in a direct injection air‐cooled diesel engine , 2000 .