激光熔覆中同轴粉末流温度场的数值模拟

在激光同轴送粉熔覆中,由于激光与粉末流相互作用,粉末流整体温度分布直接影响激光熔覆的质量.基于非预混燃烧模型,将激光相处理为连续性介质,粉末颗粒相看作离散相物质,建立了激光作用下粉末流的质量、动量和能量方程.用Fluent软件进行了不同激光功率和粉末流速度条件下粉末流整体温度场数值模拟,讨论了各种参数对温度场分布的影响.为了验证该模型的准确度,利用CCD比色测温方法测量了粉末流整体温度场分布.结果表明,数值模拟与CCD检测结果具有良好的一致性,数值模拟结果对激光熔覆具有指导意义.

Numerical Simulation of Temperature Field of Coaxial Powder Flow in Laser Cladding

In laser coaxial cladding, laser casing qualities are directly affected by temperature field of powder flow for the interaction between laser and powers. According to the model of non-premixed combustion, regarding laser beam as continuity medium phase and powder as disperse medium phase, the conservation equations of mass,momentum and energy are established in laser and powder flow. Computer simulations of temperature field in different parameters are finished using Fluent software. Some effects of laser cladding parameters on temperature distribution such as laser power and powder flow velocity are discussed. Temperature field distribution in the powder flow is measured by CCD camera. It is shown that simulation and experimental results agree well, numerical simulation of temperature field in powder flow is important for laser cladding.