介绍了Runge-Kutta光线追迹方法,并以此作为任意折射率介质中光线追迹基本手段;针对具有折射率任意分布性质并且离散的三维流场空间,建立了流场空间任意点的折射率和折射率梯度计算方法;在追迹过程中,提出了追迹步长根据当地折射率梯度和网格几何尺寸自适应调节的思想和方法,用于提高追迹的精度和效率。结果表明,建立的光线追迹方法适用于三维离散空间折射率任意分布的光线追迹,具有较高的精度和效率。

The Runge-Kutta ray tracing method is introduced firstly,which is used as a basic ray tracing method for the medium of the discretionary refraction index distribution. Then towards the three-dimensional fluid field with the characteristic of discrete refraction index distribution,a numerical computation method of any point′s refraction index and gradient is proposed. During the process of ray tracing,an idea and method that tracing step distance is self-adaptive according to local refraction index gradient and grid geometry scale are carried out,which can improve the tracing precision and efficiency. The results show that the method has high precision and efficiency for the ray tracing of three-dimensional space with the discrete refraction index distribution.