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A detailed description of flow rate measurement technique for automotive exhaust is presented. The system consists of a sector field mass spectrometer for continuous analysis of helium concentration in the exhaust gas and a mass flow controller which injects pure helium at a constant rate into the intake manifold of an engine. The exhaust flow rate can be calculated by helium injection flow rate dividing by the concentration since the concentration value is a measure of the ratio of helium dilution taking place in the engine. The advantages of the technique consist of (1) no disturbance from strong pulsed flow present when an engine is idling, (2) easy time alignment with gas analyzers, and (3) measurement of dry based flow rate that can be directly multiplied by dry based gas concentration to obtain mass emission rate.

Two new techniques have been applied to FTIR emission analysis which add significant potential to automotive emission measurement. One of these is the use of the mathematical multivariate analysis which is called the partial least squares method. This spectrum discrimination technique, in combination with high resolution spectrum data, enables superior analysis for heavy-overlapping species in the emission. The other technique is a flow conditioned gas sampling cell which is designed especially for real time emission measurement. The flow in the gas cell has been analyzed with computer simulation and the gas cell has a flow conditioner inside with a 10 meter optical path. Seven seconds of 90 percent gas replacement time can be achieved with this cell. As a result, highly accurate realtime data can be obtained with relatively fast response. In this paper, spectrum factors extracted from overlapping species and quantification simulations are shown using standard gases.

This paper presents an atomization mechanism of a spray injected into the low-pressure field, as the subject of injection system in a suction manifold of gasoline engine. Pure liquid fuel, which is n-Pentane or n-Hexane is injected into quiescent gaseous atmosphere at room-temperature and low- pressure through pintle type electronic control injector. Fuel sprays are observed by taking photographs for variation of the back pressure and the changes in spray characteristics with the back pressure below atmospheric pressure are examined in detail. In particular, in the case of the back pressure below the saturated vapor pressure of fuel, the atomization mechanism is discussed from a viewpoint of flash boiling phenomena, those are bubble growth rate and so on.