| 摘要 |
METHOD FOR DETERMINING AIR MASS IN A CRANKCASE SCAVENGED TWO-STROKE ENGINE A method is described for determining the cylinder mass of air available for combustion in a crankcase scavenged, two-cycle engine, based upon the Ideal Gas Law relationship and indications of pressure, volume, and temperature of air in the crankcase chamber, at predetermined points in the engine operating cycle. This is achieved by first determining the mass of air trapped and compressed in a crankcase chamber, and thereafter, determining the residual air mass remaining in the crankcase after the transfer of air to the associated combustion chamber. Then, the actual air mass transferred to the combustion chamber is determined as a function of the difference between the trapped and residual air masses. Engine trapping efficiency can be used to correct for air leakage from the combustion chamber prior to cylinder exhaust port closure. The volume of the air within the crankcase chamber is derived as a function of engine cycle position, with crankcase air temperature being derived as a function of intake air temperature. Air pressure in the crankcase is monitored with a pressure transducer.
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