A Computational Study of 3-D Supersonic Flow for Evaluating Aero-optic Boresight Error

Abstract

The present research conducts the numerical study for analyzing the relation between three-dimensional supersonic flow structures and boresight errors of the light through the flow field. When the light propagates through a supersonic flow, drastic change of density due to the shock wave results in the deviation from the initial straight-lined trajectory, which is called boresight error. This aero-optic phenomenon is especially important for guidance systems such as flight vehicles with infrared homing tech- niques. In this thesis, boresight error is obtained via ray tracing algorithm, which directly calculates the trajectory of light through the density flow field acquired from the three-dimensional compressible flow solver. Boresight error is calculcated for the three-dimensional realistic flight vehicle geometry flying at supersonic speed, and the analysis indicates that the boresight error is dependent on the shock angle and strength in front of the nose.