Effect of abrasive parameters on nozzle wear in low-pressure abrasive air jet machining

Zhang Hongtu; Ye Hongyan; Liu Yong; Wei Jianping; Li Zhiping

doi:10.16186/j.cnki.1673-9787.2024030064

Abstract：Objectives The rapid wear of low-pressure abrasive air jet nozzles,caused by the erosion of high-speed abrasive particles inside the nozzle,limits the efficiency of rock breaking.This study aims to analyze the influence of abrasive parameters on nozzle wear to provide guidance for reducing wear and improving rock-breaking efficiency.Methods A Laval nozzle was selected as the research object.Coupled numerical simulations were performed using FLUENT-EDEM and Relative Wear models.Key abrasive parameters—in-cluding mass flow rate,particle size,shape,and type—were varied in the simulations.Wear depth was used as the evaluation criterion to assess the effects of these factors on nozzle wear.Results Wear predomi-nantly occurs in the convergent section of the nozzle within 6 mm from the inlet,with the maximum wear concentrated between 2.62 mm and 3.28 mm from the inlet.Beyond this zone,the abrasive particles form a beam flow along the nozzle axis,causing no significant wear in the nozzle's downstream convergent and ex-pansion sections.The wear pattern is closely related to the abrasive collision velocity and frequency with the nozzle wall.Increased abrasive mass flow results in more frequent collisions and deeper wear.Larger particle sizes increase collision energy,thereby intensifying wear.Particles with lower sphericity and sharper edges cause greater wear.Among different abrasive materials,garnet causes the most severe wear due to its material properties such as density,shear modulus,and Poisson's ratio.Conclusions This study highlights the critical influence of abrasive collision dynamics and material properties on nozzle wear,offer-ing theoretical guidance for reducing wear.