针对短脉冲高功率热流作用下的薄壁金属导热问题,基于傅里叶导热模型,采用固液耦合计算方法对金属瞬态温度特性进行了数值仿真,并分析了液体工质流速及固体材料物性参数对金属温度瞬态响应和分布的影响作用.分析结果表明:温度响应特性与时间尺度有关,在单次脉冲作用下,在ms量级内热量才能开始通过水侧对流散热散出,25 ms后金属内部温度渐趋平衡;在连续脉冲作用下,金属内部温度逐渐升高,一定时间后温度变化达到动态平衡,壁面温度在一定范围内波动;停止加热后,在2 s内温度逐渐降低至初始状态.提高水的流速和固体壁面热扩散系数均可降低壁面温度,且缩短温度趋衡所需时间.

Fourier heat transfer model and solid-liquid couple method were used to analyze the thermal characteristics of thin-wall metal under nanosecond laser pulse.The high-power heat source operated with a fixed pulse width of 30 ns.It is found that the changes of fluid and solid wall temperature depend on operating time.During an individual pulse,the inside temperature in solid wall increases rapidly within 30 ns pulse heating period,then begins to decrease after 1ms.After 50 ms,the radial distribution of solid temperature becomes uniform gradually.Under the repetitively operated pulse with 40 Hz frequency,the wall temperature oscillates with the same frequency.After a certain time,the temperature oscillation becomes equilibrium and changes within a certain range.If the pulse heating is stopped,both the fluid and wall temperature will sharply decrease to the initial values within 2 s.The effects of fluid flow rate and physical properties of solid wall are also discussed.Both the increase of flow rate and solid thermal diffusivity can decrease the wall temperature and accelerate thermal balance.