Hypersonic Aero-Optic Analysis and Imaging Framework (HAAWK)

The complex and harsh hypersonic environment, with high aerodynamic and thermal loads poses challenges to materials, structures and on-board sensors needed for target tracking, telemetry, communication, and navigation. High surface temperatures require advanced optical window materials and potentially cooling mechanisms. Aerothermal loads interacting with optical sensors include shock waves, causing strong, sharp density gradients, acting as a lens; turbulent boundary layer or wake flow; high-temperature gas and plasma effects due to non-equilibrium air behind shocks, resulting in background radiation, and in turn interacting with the sensor system. Optical window emissions and thermal deformation can also cause additional optical aberrations at the focal plane of the imaging system. In response to those challenges and needs, and within this proposed Phase II effort, CFD Research will leverage past performance and expertise in high-fidelity physics-based and fast-running reduced-order modeling and simulation to continue to build the Hypersonic Aero-optic Analysis and imaging frameWorK (HAAWK). An experimental campaign at CUBRC’s LENS-I and LENS-XX hypersonic facilities will be executed, addressing aero-optical and spectroscopic wake measurements of a generic Common Hypersonic Glide Vehicle (C-HGV) type geometry, providing wavefront information (OPD), and data derived from the point spread function (PSF) including boresight shift, blur and Strehl ratio, etc. as well as spectral emission lines. The experimental data will serve as validation for the in-house developed optical and radiation simulation tools. Reduced-order and surrogate models will be developed, enabling fast execution of the framework. A proof-of-concept demonstration will show HAAWK’s capabilities of rapidly generating databases along hypersonic trajectories, describing the image aberration due to aero-optical and radiative effects. CFD Research uses scene generation to visualize these imaging aberrations. The database information can then be used by third-party sensor manufacturers to develop an on-board compensation algorithm, or, for software- and hardware-in-the-loop (SWIL/HWIL) simulations, supporting ground test validation and verification (V&V) efforts of sensor systems of interest.