Simulation Of The CO₂ Flow Field And Arc Temperature Field Based On The Rotating Arc Sensor For V-Shaped Welding

The distribution law of rotating arc protective gas flow field and arc temperature field is great significance to the formation of rotating welding,welding defects,optimization of welding process and sensor structure design.Since rotating arcs have rotating characteristics and involve relatively complex physical processes such as electric fields,magnetic fields and temperature fields,it is time-consuming and labor-consuming for the rotating arc heat transfer and fluid flow process by experimental methods,numerical simulation of flow field and temperature field is a feasible method.V-shaped welding is one of the more typical forms of weld in rotating arc welding,to obtain its protective airflow and temperature fields,based on magnetohydrodynamics and the assumption of arc model,through the establishment of V-shaped welding rotating arc three-dimensional model,the rotating arc calculation area,the thermodynamic and transport properties of the shielding gas and air,reasonable boundary conditions are determined,ANSYS CFX software was used to simulate,the distribution of the protective gas flow field and arc temperature field were obtained.The specific content of the paper:?1?Research on the status of welding arc at home and abroad,identify the purpose,significance,and goals of the project.Analysis of fluid dynamics,thermodynamics,and heat transfer involved in welding arcs,based on the analysis of the finite element solution method,the basic theory of the project simulation and the analysis tool software ANSYS CFX were determined.?2?Based on the above theory and software,found a three-dimensional mathematical model of arc flat surfacing.Based on this model,determine the rotating arc calculation area,reasonable boundary conditions,CO₂ and air thermodynamics and transport properties parameters;Simulation of CO₂ flow field and arc temperature field for rotating arc flat welding with and without weld pool.Rotating arc flat welding temperature field,CO₂ velocity,and CO₂ volume fraction were obtained,comparing the simulation results of no-pool and molten pool,found that the bath will hinder the flow of gas,change the arc discharge mode and change the shape of the arc;tests were conducted and the test results were consistent with the simulation results,confirmed the reliability of the simulated three-dimensional mathematical model,arc calculation area,boundary conditions,etc.?3?Based on flat welding simulation results,consider the difference in V-shaped welding parameters,wire ends,and wire elongation during welding,a three-dimensional mathematical model of rotating arc V-welding was established,simulate the protective airflow field and arc temperature field in its welding process.The distribution of temperature field,CO₂ velocity and CO₂ volume fraction of rotating arc V-welding under different elongations of the welding wire were obtained.The temperature of the welding arc is almost unchanged,the arc discharge path and the arc shape are changed,and there is a low volume fraction area in the protection range area,but the overall protection effect is good.The above simulation results can provide reference for the selection of process parameters and high quality seam welding for rotating arc V-shaped welding.