基于有限差分法的焊接熔池中耦合场的数值模拟

针对TIG（钨极惰性气体保护电弧焊）焊接熔池中流场和温度场的耦合问题,建立了一定条件下的焊件上液体区域的温度、速度、压力等变量和固体区域的温度变量之间强耦合的三维瞬态控制方程及初始条件和边界条件,运用有限差分法与牛顿迭代法、超松弛方法相结合的数值方法对该数学模型进行了求解,并对0Cr18Ni9不锈钢薄板的TIG焊接熔池中流场和温度场进行了数值模拟.模拟结果验证了该数学模型和所采用的数值方法的有效性,为TIG焊接熔池的数值模拟及与其类似的实际问题的数值模拟提供了理论依据和实验数据.

Numerical simulation of coupling field in weld pool based on finite difference method

Aiming at the coupling problem physical fields of temperature and flow in the TIG（tungsten inert gas arc welding） weld pool,three-dimensional transient control equations,initial conditions and boundary conditions are determined under the certain conditions of strong coupling interaction among variables of temperature,velocity and pressure in liquid region and variable of temperature in solid region.Numerical methods includes finite difference method,Newton iteration method and super over-relaxation method are applied to solve the mathematical model.Flow field and temperature field in the TIG weld pool of 0Cr18Ni9 stainless sheet are simulated.The conclusion verifies that the feasibility and validity of the mathematical model and numerical method adopted.Furthermore,the theoretical reference and experimental data for numerical simulation of the weld pool and the similar actual problems can be provided.