Finite Element and Experimental Vibration Analysis of High-Pressure Fuel Injection Pipe for 8-Cylinder V Diesel Engine

Designing of fuel injection pipe for high fuel pressure and vibrations is most important for a diesel engine’s safety and performance. The failure of the fuel injection pipe of a Diesel engine is critical when running at full load condition. This paper presents the mode shapes, natural frequencies, and harmonic analysis of fuel injection pipes to identify the cause of failure. Finite element analysis is conducted to study dynamic behavior under a range of excitation frequencies. In these natural frequencies and mode shapes about the fuel, injection pipe is presented for different configurations. The methodology is prepared to avoid pipe failure by providing clamps at a proper location following modal parameters and providing sufficient damping in a fuel injection pipe assembly. Results indicate that excessive vibration amplitudes and incorrect clamp’s location are responsible for failure (cracks in fuel injection pipes at the diesel engine’s injector side). Different fuel injection pipe assemblies are discussed, control strategies and experimental results are presented to reduce vibration amplitude and stress. The existing fuel injection pipe assembly’s overall vibration amplitude is reduced to 34.5 % and stress by 75 % through the modified assembly.