基于流固耦合的高压油管振动疲劳特性研究
Vibration Fatigue Characteristic of High-Pressure Fuel Pipe Based on Fluid-Solid Coupling Model

以高压油管为研究对象，开展了基于流固耦合方法的振动疲劳特性研究。通过计算流体力学(computational fluid dynamics, 简称CFD)仿真获取高压油管内部燃油脉冲压力，并建立高压油管流固耦合模型进行振动特性仿真分析，能更准确地预测高压油管的振动疲劳寿命。结合发动机振动激励功率谱密度(power spectral density，简称PSD)信号、材料S-N曲线和传递函数结果，通过疲劳损伤累积模型进行了两种高压油管模型的振动疲劳寿命预测，对比分析了考虑燃油脉冲压力对振动疲劳寿命的影响，为后期高压油管的优化设计提供了指导。
As an important part of fuel supply system of diesel engine, the fatigue life of the high-pressure fuel pipe directly affects the normal operation of the engine. The fuel pulse pressure of the high-pressure fuel pipe has a great impact on the vibration fatigue life of the pipe. It has important significance to carry out research on vibration fatigue characteristic of the high-pressure fuel pipe based on fluid-solid coupling method. The fuel pressure pulse of high-pressure fuel pipe is obtained by computational fluid dynamics (CFD) simulation, and the result is used to establish the fluid-solid coupling model of high pressure pipe. The vibration characteristic simulation analysis base on the fluidsolid coupling model can predict the vibration fatigue life of high pressure pipe more accurately. According to the power spectral density (PSD) signal, material S-N curve and the transfer function results, the vibration fatigue lives of two high-pressure fuel pipe are predicted through the cumulative fatigue damage model. The comparative analysis of different vibration fatigue life results can provides guidance for the optimization design of the high-pressure fuel pipe.