钛合金板翅式结构双热源真空钎焊过程热流耦合仿真研究

Thermal‑fluid coupling simulation study on double heat source vacuum brazing process of titanium alloy plate‑fin structure

本文构建了电阻生热与辐射加热双热源耦合作用下的钛合金板翅结构真空钎焊过程热-流耦合模型,对比分析了单热源与双热源温度场的差异性,探明了双热源作用下的钛合金板翅结构真空钎焊过程温度场分布与钎料流动规律。结果表明,板翅式结构外侧区域温度高,中心区域温度低,双热源作用下板翅构件表面温度较高。这是由于热传导传温效率更高,双热源作用下板翅结构的升温速率更快。整个加热过程中,单热源加热的板翅结构温差最大约155 K;在双热源作用下,板翅结构温差最大约70 K。因此,在辐射-电阻双热源的共同作用下工件的温度均匀性得到了明显改善。钎料流动分布同温度场分布相似,温度越高钎料熔化越充分,流动性越好。

The thermal-flow coupling model for vacuum brazing process of titanium alloy plate-fin structure under the coupling effect of dual heat sources of resistance heat generation and radiation heat⁃ing is constructed in this paper.The disparities in the temperature field between a single heat source and dual heat sources are meticulously compared and analyzed.The temperature field distribution dur⁃ing the vacuum brazing process of titanium alloy plate-fin structures under the influence of dual heat sources is investigated,along with the flow characteristics of the brazing filler material.The results in⁃dicate that the heating rate of the dual heat source is promoted due to the higher efficiency of heat con⁃duction compared to single heat source.When entering the final insulation stage,the resistance heating is disconnected and the temperature field distribution of the plate-fin structure under the action of dual heat sources is the same as that of the single heat source,with high temperature in the outer area and low temperature in the central area.During the whole heating process,the temperature difference of the plate-fin structure heated by single heat source is gradually increased to about 155 K.By compari⁃son,under the dual heat source heating,the temperature difference is decreased from a maximum of about 70 K to about 5 K with constant fluctuations.Therefore,the temperature uniformity of titanium alloy plate-fin structure is significantly improved under the combination of radiation-resistance dual heat source.Meanwhile,the distribution of brazing filler metal flow is similar to the distribution of tempera⁃ture field.The higher the temperature,the more sufficient the brazing filler metal melts and the better the fluidity.