The Internal Combustion Optical Sensor (ICOS) from LaVision provides a measurement technique for highly time resolved gas analysis directly in the combustion chamber of internal combustion gasoline or diesel engines. Highly time resolved data of the relevant engine parameters air/fuel-ratio and CO2-concentration are recorded and detailed visualized. This offers the analysis of individual variations for hundreds of consecutive cycles.
The diagram shows an example of the crank angle resolved fuel density evolution of a catalytic converter heating point measured at the spark plug. The corresponding %lambda%-value curve is derived from the fuel density and in-cylinder pressure. After the double injection the fuel density rises during compression to TDC and decreases again with the beginning of expansion. The cycle shows an abnormal delayed combustion. Ignition takes place at 28°CAaTDC, while the fuel signal disappears significantly later. The drop in the fuel density at 100 °CAaTDC marks the appearance of the flame front locally at the probe tip.