Real Time Models for Predicting Optical Seeker Window Distortions for HWIL

Hypersonic vehicles are designed to pursue deeply protected targets at very high speeds and long ranges, making them a critical offensive and defensive technology. As such, the U.S. Air Force, U.S. Navy and other DoD agencies have identified a growing need to develop hypersonic missile systems. New technologies have been pushing the system limits of speed, range, and high-temperature exposure times. These extreme conditions make designing many of the critical components of a hypersonic vehicle very challenging. Reproducing the operating conditions in ground test facilities is nearly impossible, while test flights can be cost prohibitive especially during early design phases. Tests for avionic software can be done at comparatively low-cost and in a repeatable environment within hardware-in-the-loop (HWIL) facilities. These HWIL stimulations help assess performance and reduce risks prior to full flight testing but come with several technical challenges. One such challenge is providing sensor stimuli that will result in realistic feedback to the avionics. Though aero-optical tools exist for predicting image distortions due to features of hypersonic flow fields, image degradation due to optical propagation through a heated and deformed window are missing. Because these thermal-structural effects can be critical for some designs, there is a need for real-time capable models suitable for closed-loop trajectory simulations that can capture both the aero-optical and thermal-structural distortions.Recognizing this need and opportunity, CFD Research Corporation in collaboration with Kinetics Incorporated proposes a workflow to provide a fast aero-optical and thermal-structural effects model that can be easily integrated with scene generators currently existing in hardware-in-the-loop facilities. Phase I will focus on: (1) generating databases of optical parameters using high-fidelity physics-based toolchains, (2) training surrogate models to predict these parameters, and (3) creating a GPU compatible application or FLITES plugin, to incorporate the optical effects into the scene generation pipeline.