基于RKPM的n-octadecane熔化过程光热特性数值模拟与验证

RKPM numerical simulation for photothermal characteristic of n-octadecane with melting process

建立求解一维半透明材料相变过程的辐射导热耦合计算方法,了解正十八烷(n-octadecane)在辐射源作用下的相变熔化过程,获得材料内部温度分布,验证数值方法准确性。基于无网格RKMP方法,采用修正等效热容法处理相变潜热的吸收与释放,利用梯度折射率的方法处理变折射率介质内的辐射传输问题。实验测量了n-octadecane在红外辐照加热条件下的熔化过程温度响应特性。结果表明数值模拟值和实验值在温度水平和时间特性两方面都符合良好,验证了计算方法具有良好的精度。

To establish coupling algorithm of radiation and conduction for one-dimensional translucent material with phase change, to understand the melting process of n-octadecane with infrared irradiation source, and to obtain the temperature distribution in the material, the modified equivalent heat capacity method is used for latent heat absorption and release with transient heat transfer, the gradient refractive index method is used for radiative transfer in variable refractive index medium, and a calculation method is established for phase change process of coupling radiation and conduction of one-dimensional semitransparent materials based on the reproducing kernel particle method（RKPM）. The temperature response characteristics of n-octadecane with phase change were measured experimentally under the infrared radiation heating condition to verify the accuracy of numerical method. The results show that numerical simulation values match the experimental values well both in the temperature level and time characteristics, indicating that the method has very good accuracy. The selection of convective heat transfer coefficient has a certain influence on the simulation results.