Development of the Hypersonic Environment - Sensor EO/IR Effects Software (HySEES)

ABSTRACT: Electro-optic/infrared (EO/IR) sensors are key to the mission success of future hypersonic vehicles. Although EO/IR sensors have been extensively used for subsonic flight regimes, the hypersonic flight regime creates new conditions and complexities with significant impact on optical sensors. These complexities include turbulent, high temperature gas that is in Non-Local Thermodynamic Equilibrium (NLTE) and aerothermodynamic heating that creates large thermal gradients within materials exposed to the flow. Currently, no tool exists that enables end-to-end simulation of the optical sensor environment of hypersonic vehicles. The goal of this R&D by Spectral Sciences, Inc. and the University of Minnesota is to develop the HySEES package. HySEES is a simulation tool to predict the hypersonic flow, simulate the impact of the hypersonic environment on EO/IR sensors, and explore potential mitigation techniques. Phase I would provide a proof of principle framework for the simulation tool, with focus on evaluating NLTE and turbulence effects, and document technology gaps that prevent more effective solutions. In Phase II, the software will be further extended and validated to enable detailed study of the impact of hypersonic flight on sensors. Finally, it will be used to evaluate potential mitigation strategies.; BENEFIT: The proposed work will have a wide application when highly accurate models of complex non-local thermodynamic equilibrium (NLTE) gas and the associated radiative transfer predictions are required. The HySEES package produced in this effort will be capable of simulating a broad range of effects including: NLTE radiation and chemistry, turbulent flows, material response, and 3D and unsteady flows. Military applications include sensor developers and system integrators for hypersonic vehicles. In addition to analysis of current designs, system integrators can leverage the tool to explore novel mitigation techniques that result in more robust hypersonic sensor systems. HySEES can also be used as a validation tool to interpret and validate existing chemistry and radiation models with high fidelity experimental measurements. Furthermore, work on validating and hardening HySEES will aid other DoD programs that use the underlying radiation transport libraries. Commercial applications include advanced modeling software for the development of sensors on commercial space vehicles and understanding calibrated species concentrations for high temperature rate processes, including combustion.