Experimental and simulation research of performance degradation of jet pipe servo valve under wedge erosion of jet amplifier

Due to the erosion of solid particles in contaminated oil, the material of the wedge of the jet amplifier falls off, and the wedge structure deforms, which inevitably leads to irreversible performance degradation and even failure of the jet pipe servo valve (JPSV). In this study, the experimental analysis of the performance of the JPSV before and after wedge erosion is carried out. According to the physical object of wedge erosion, the three-dimensional model of the jet amplifier after wedge erosion is reconstructed. Based on computational fluid dynamics (CFD) simulation, the comparison results of the flow field of the jet amplifier before and after wedge erosion are analyzed to explain the performance degradation of the JPSV. Furthermore, the relationship between the erosion degree of the wedge and the performance deterioration of the JPSV is investigated. The experimental and simulation results indicate that the dynamic behavior of the JPSV will gradually degrade with the increase of the erosion degree of the wedge, and the degradation process is nonlinear. Additionally, through CFD simulation, it is revealed that the critical factor causing the dynamic performance deterioration of the JPSV is that after wedge erosion, the shunting effect of the wedge is weakened, and the flow field of the jet amplifier changes significantly. This paper provides a new reference and practical method for studying and predicting the performance degradation of the JPSV caused by wedge erosion.