表面技术2026，Vol.55Issue(1)：231-239,249,10.DOI:10.16490/j.cnki.issn.1001-3660.2026.01.020
流磁固耦合超音速冷喷涂铁粒子数值模拟研究
Numerical Simulation of Iron Particles in Fluid-magnetic-solid Supersonic Cold Spray
摘要
Abstract
The key component of cold spraying technology is the supersonic nozzle.Currently,in the field of cold spraying technology,linear nozzles are mostly used,while bent nozzles have received little research.The difficulty with bent nozzles lies in the fact that supersonic particles are prone to collide inside the nozzle,resulting in significant loss of particle kinetic energy and preventing deposition.However,bent nozzles have obvious advantages in engineering applications in special areas,such as the inner walls of cylinders and turning points.There is an urgent need to study cold-sprayed bent nozzles.This article takes iron particles as an example.By using a magnetic field to assist iron particles in deflection within supersonic nozzles,it can reduce the impact of disorders of iron particle within the nozzles,thereby meeting the deposition requirements. To study the collision of iron particles in the bent nozzle of cold spray,a coil is applied to the bent nozzle to form a non-uniform magnetic field,which makes the iron particles deflect angularly under the action of the magnetic field.The trajectory of the particles is corrected in combination with the turbulent gas field in the nozzle to reduce the collision probability of iron particles in the bent nozzle and reduce the kinetic energy loss of particles.The velocity,pressure,temperature,and particle trajectory of the gas flow field in the bent nozzle with 90° and 60° bending angles are simulated numerically by constructing a Comsol Multi-Physics coupling module.Because the continuous phase gas selected is helium,its flow field characteristics are not affected by the magnetic field.However,due to the geometric structure of the bend,the vortex flow field forms above the bend section and interacts with the incoming flow,making the airflow show a trend of decreasing velocity,increasing pressure,and increasing temperature in the expansion section.Meanwhile,the airflow velocity at the central axis is the fastest and decreases to the upper and lower walls.Without magnetic field coupling,the particles in the bend hit the wall one after another,resulting in a particle velocity of only about 400 m/s at the exit.At the same time,the particles released at the same time have a large time difference when they reach the outlet,which makes the spraying process unstable.Under the background of the inhomogeneous magnetic field,the relative permeability of iron particles is much larger than that of helium,so the micron particles are deflected to a higher magnetic field gradient by the positive magnetophoresis effect in an inhomogeneous magnetic field.The five particles in the two bends realize effective deflection motion,and the particles arrive at the exit at adjacent time nodes.Except for some particles in the bend of 90°,which were restrained by the magnetic field and appeared a transient stall phenomenon,the rest particles have no collision trajectory,and their velocity reaches the critical velocity required for deposition. Under the conditions of magnetic field and flow field,supersonic iron particles have obtained superior movement trajectories in the cold-sprayed bent nozzle,providing a theoretical reference for the field of bent nozzles,a core component of cold spraying technology.关键词
冷喷涂/COMSOL Multiphysics/流磁固耦合/正磁泳Key words
cold spray/COMSOL Mulitphysics/fluid-magnetic-solid coupling/positive magnetophores分类
矿业与冶金引用本文复制引用
胡文杰,许竞元,曹婷婷,谭锟..流磁固耦合超音速冷喷涂铁粒子数值模拟研究[J].表面技术,2026,55(1):231-239,249,10.基金项目
江西省教育厅科学技术项目(GJJ2202721) （GJJ2202721）
南昌理工学院高层次人才科研启动基金 Science and Technology Project of Education Department of Jiangxi Province(GJJ2202721) （GJJ2202721）
Nanchang Institute of Technology High-Level Talent Research Start-up Fund Support （）
