Pneumatic flow mixing method can be widely applied to the ex-situ solidification and resource utilization of large-scale dredged mud.However,there has been a lack of quantitative research on the impact of key process and structural parameters on mixing uniformity,leading to a reliance on engineering experience for structural design and construction.Utilizing multiphase flow numerical simulation methods,this study investigates the spatial distribution characteristics of curing agent and the variation laws of mixing uniformity under the influence of mud,curing agent,and air inlet velocity,as well as the expanded pipe diameter for both conventional and improved structures.The results indicate that under conditions that the expended pipe diameter is 200 mm and the mud inlet velocity is equal to or larger than 4 m/s,the uniformity coefficient at the outlet of the improved structure can be reduced by 50%-58% compared to the conventional structure.For the improved structure,every 1 m/s increase in the inlet velocity of mud,curing agent,and air results in an average reduction in the uniformity coefficient at the outlet of 0.26,0.70,and 0.26,respectively.Additionally,mixing uniformity improves with the increase of the extended pipe diameter and when the diameter is increased from 200 mm to 500 mm,the uniformity coefficient at the outlet can be reduced by approximately 40%.