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Diesel injector dynamic modelling and estimation of injection parameters from impact response part 2: prediction of injection parameters from monitored vibration

By Fengshou Gu, Andrew Ball and K K Rao


Part 2 of this paper presents the experimental and analytical procedures used in the estimation of injection parameters from monitored vibration. The mechanical and flow‐induced sources of vibration in a fuel injector are detailed and the features of the resulting vibration response of the injector body are discussed. Experimental engine test and data acquisition procedures are described, and the use of an out‐of‐the‐engine test facility to confirm injection dependent vibration response is outlined.\ud \ud Wigner‐Ville distribution (WVD) analysis of non‐stationary vibration signals monitored on the injector body is used to locate regions of vibration in the time‐frequency plane which are responsive to injection parameters. From the data in these regions, estimates of injection timing and fuel pressure are obtained.\ud \ud Accurate estimation of injection parameters from externally monitored vibration is shown to pave the way for the detection and diagnosis of injection system faults. Moreover, it is demonstrated that the technique provides an alternative method for the set‐up, checking and adjustment of fuel injection timing.\ud \ud Table 1 caption: Test engine specification\ud \ud Fig. 1 caption: Injector vibration versus cylinder pressure, line pressure and needle lift\ud \ud Fig. 2 caption: Bench‐top test rig layout and data acquisition system\ud \ud Fig. 3 caption: Injector vibration and needle motion from bench‐top testing\ud \ud Fig. 4 caption: Engine test layout and data acquisition system\ud \ud Fig. 5 caption: Time‐frequency analysis of injector vibration\ud \ud Fig. 6 caption: Time‐frequency analysis of injector vibration at 3000 r/min\ud \ud Fig. 7 caption: Timing of the fuel injection process\ud \ud Fig. 8 caption: Comparison of needle lift and vibration derived injection timing\ud \ud Fig. 9 caption: Comparison between injection line pressure and injector vibration\ud \ud Fig. 10 caption: Relationship between injector vibrtation and line pressur

Topics: T1, TL
Publisher: Professional Engineering Publishing
Year: 1996
OAI identifier: oai:eprints.hud.ac.uk:6788

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