Cellular automata ray tracing in flow field near the optical window of the optical dome

Abstract

For the supersonic flow field with large density fluctuation, an effective method to obtain the beam path is solving ray equation. Generally, when the refractive index distribution is arbitrary, obtaining the ray equation analytic solution is difficult. Cellular Automata (CA) ray tracing algorithm is proposed in this paper for aero-optical calculation in flow field near the optical window of the optical dome. Different from numerically solving the ray equation (NSRE), the coordinate value and the offset angle are calculated according to the position and direction transformation rules in CA algorithm. Then the refractive index field is integrated along the beam path to obtain the optical path length (OPL). The optical path difference (OPD) is calculated from OPL. The OPDrms results quantitatively verify the calculation accuracy. Then the time complexity verifies high efficiency of CA. The results show that CA algorithm is applicable to ray tracing and can simplify the calculation in 3D aero-optical flow field.

Keywords

• Cellular automata
• Aero optics
• Ray tracing