Measurement of liquid fuel film distribution on the cylinder liner of a spark ignition engine using the laser-induced fluorescence technique

Two-dimensional visualization of a liquid fuel film on a quartz cylinder liner was performed in a spark ignition engine rig. The visualization method was based on laser-induced fluorescence and total reflection. Using a quartz cylinder liner and a special quartz prism, only the liquid fuel on the cylinder liner was visualized. The calibration method was developed to quantify the fuel film thickness on the quartz cylinder liner. The calibration result showed that the fluorescence intensity increased linearly with the fuel film thickness on the quartz cylinder liner. Using this method, the wall-wetting fuel mass on the cylinder liner was quantitatively measured for different valve lifts and injected fuel masses in the test rig. The maximum fuel film thickness on the quartz cylinder liner was about 45 µm for a valve lift of 8 mm and an injection duration of 10 ms.