Radiative Transfer Calculations on Hybrid Unstructured/Structured Flowfield Grids

The field of CFD has witnessed dramatic maturation of unstructured, hybrid multi-element technology, along with implementation of such simulation methodology on large-scale multi-processor parallel, computational architecture. Absence of equivalenttechnology for radiative transfer simulations limits radiative transfer analyses (for missile heating or IR signature studies) to single CPU simulations on structured grids. The proposed effort is rectifies this limitation by via the systematic development& validation of a novel unstructured grid technique for conducting radiative transfer simulations. The new model will employ hybrid multi-element grids and operate in a multi-CPU, parallel processor computational environment. The ability to performlocalized mesh adaption is a key feature of the new unstructured grid IR methodology. The developmental activities of the SBIR program will be accompanied by systematic validation against industry-standard IR methodology, using identical physics (bandmodels, atmospheric transmission, and scattering models). IR signature predictions will be demonstrated for several scenarios, e.g. tactical missile, threat ballistic missiles (TBM) divert jets on hypersonic interceptors, etc. Application to aircraft andhelicopter plume flowfields will also be conducted to assess geometrical versatility and overall fidelity of the new technique. A fully validated, efficient, unstructured grid capability for performing IR predictions will result from the proposedeffort.The technology development proposed is of direct relevance to Boost Phase Intercept (BPI) and will aid in assessing the potential of innovative hardware technology developments proposed for space and sea-based kinetic energy BPI concepts. The IRcapability development is also of direct relevance to other major DoD initiatives of current relevance, e.g. Joint Strike Fighter (JSF), Unmanned Combat Air Vehicle (UCAV), V-22 Osprey, etc. For commercial dual-use applications, this technology is directlyapplicable to remote sensing of the atmosphere for weather modeling & prediction, environmental studies of the earth, pollution monitoring, ocean temperature, etc.