COMPUTATIONAL FLUID-DYNAMICS VALIDATION ISSUES IN TRANSITION MODELING

Laminar-turbulent transition is highly initial- and operating-conditio n dependent, Finding careful, archival experiments for comparison is t he main validation issue for computational fluid dynamics (CFD) modeli ng. The CFD formulations validated to date demonstrate that if the env ironment and operating conditions can he modeled and input correctly, the computations (nonlinear parabolized stability equations and direct numerical simulations) agree quantitatively with the experiments. Fut ure challenges for validation include successful CFD simulations of ot her available complete databases, CFD leadership in the identification and modeling of the effects of freestream disturbances, CFD leadershi p in the determination of relevant validation experiments for superson ic and hypersonic flows, careful validation experiments and CFD soluti ons for complex three-dimensional geometries, and simulations and vali dations for the high Reynolds numbers of flight.