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Activity title

Vortex Interaction Effects Relevant to Military Air Vehicle Performance

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Applied Vehicle Technology

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CFD capabilities, compressible flow, flow simulation, incompressible flow, maneuver performance, vortex breakdown, Vortex flow, vortex interaction


Modern air tactics require agile maneuverability capability that includes operations at high angles of attack and sideslip. Military air vehicles routinely develop multiple, close-proximity vortices within required operating conditions. Interactions among these vortices, between the vortices and the vehicle components, and at high speeds, between the vortices and shock waves significantly affect maneuver performance, often with adverse consequences. Current capability to predict these effects with CFD is inadequate, and some aspects of the vortex-interaction flow physics are not well understood. Previous STO activities have not focused on the prediction of vortex interactions and their effects on military vehicle performance.


The objectives are: to evaluate the capability of current CFD methods to predict vortex-interaction effects pertinent to realistic problems of interest to NATO, to extend our understanding of vortex-interaction flow physics for these problems through numerical and physical experimentation, to enhance our capability for these predictions, and to develop recommendations for future development. Expected achievements could include improved predictive capability of vortex interaction effects important to military vehicle maneuver performance. Current Technology Readiness Level for this topic is estimated to be 2, and the results of this effort could increase this TRL to 3.


Close-proximity vortex interactions that could occur between vortices, between vortices and vehicle components, and/or between vortices and shock waves and that are relevant to military air maneuver performance. Computations will emphasize high-fidelity CFD methods including RANS and hybrid RANS-LES technologies. Wind tunnel experiments will emphasize measurements of vortex-interaction effects that will guide CFD method enhancements.

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