We combine data assimilation and machine learning to correct the RANS Spalart-Allmaras turbulence model. The final neural-network contribution is a Boussinesq-correction, rather than turbulent eddy-viscosity adjustment. Flows over periodic hills at distinct Reynolds numbers geometries were selected demonstrate potential gain of learning-augmented models.

A series of RANS-based aerodynamic shape optimization for an 800-passenger blended-wing-body aircraft is performed. A gradient-based optimization algorithm and a parallel structured multiblock RANS solver with Spalart–Allmaras turbulence model are used. The derivatives are computed using a discrete adjoint method considering both frozen-turbulence and full-turbulence assumptions. A total of 274...

Reynolds-Averaged Navier-Stokes (RANS) methods have become an important design tool in aerospace industry. Turbulence models, which are required for closure of the RANS equations, are a substantial component in these methods. Several flow regimes exist where the accuracy of flow predictions depends strongly on the turbulence model used. Turbulence has a major influence on the growth rate of bou...

Four turbulence models are described and evaluated for transonic flows using the upwind code CFL3D and the central-difference code TLNS3D. In particular, the effects of recent modifications to the half-equation model of Johnson-King are explored in detail, and different versions of the model are compared. This model can obtain good results for both two-dimensional (2–D) and three-dimensional (3...

The increased traffic emissions and reduced ventilation of urban street canyons lead to the formation of high particle concentrations as a function of the related flow field and geometry. In this context, the use of advanced modelling tools, able to evaluate particle concentration under different traffic and meteorological conditions, may be helpful. In this work, a numerical scheme based on th...

A procedure is presented to accurately model transient motions of launch vehicles associated with complex flow conditions. The flow is modeled using the Reynolds-Averaged NavierStokes equations with the one-equation Spalart-Allmaras turbulence model. An overset grid system with a curvilinear near-body grid and a Cartesian off body is used. Solution quality is assessed using grid sensitivity and...

RANS simulations with the Spalart-Allmaras turbulence model are improved for cases flow separation using Field Inversion and Machine Learning approach. A compensatory discrepancy term is introduced into optimized high-fidelity reference data from experiments. Influences on optimization results respect to regularization, grid resolution areas in which active investigated. Finally, a neural netwo...

Numerical simulations are performed using a Reynolds-averaged Navier-Stokes (RANS) flow solver for a circulation control airfoil. 2D and 3D simulation results are compared to a circulation control wind tunnel test conducted at the NASA Langley Basic Aerodynamics Research Tunnel (BART). The RANS simulations are compared to a low blowing case with a jet momentum coefficient, Cμ, of 0.047 and a hi...