Technical Paper
Oil Transport Phenomena during extreme load transients inside the power cylinder unit as investigated by HS-2DLIF (High-Speed 2D Laser-Induced Fluorescence)
2019-12-19
2019-01-2363
This paper presents findings of optical investigations conducted via the HS-2DLIF (high-speed two-dimensional laser-induced fluorescence) technique under extreme transient conditions. These extreme conditions are a transition from WOT to closed throttle and vice versa. The goal is to gain a better understanding of oil transport magnitudes and timescales for transitions to and from extreme throttled conditions. These conditions are similar to the boundary conditions found during cylinder deactivation. The transients were conducted under motored conditions with injection and spark disabled in a speed range from 650 rpm to 3000 rpm. The load was transitioned from WOT to different low load conditions (closed, 150 mbar and 200 mbar), held at that low load for a variety of durations (10 sec - 600 sec), before going back to WOT. The experiments showed a strong dependence of oil transport on speed and load. The higher the speed, the faster the oil transport.
