An adaptive method for high-order discretizations of the Reynolds-averaged NavierStokes (RANS) equations is examined. The RANS equations and Spalart-Allmaras (SA) turbulence model are discretized with a dual consistent, discontinuous Galerkin discretization. To avoid oscillations in the solution in under-resolved regions, particularly the edge of the boundary layer, artificial dissipation is ad...

This paper presents a nite element formulation for solving multidimensional compressible ows. This method is inspired by our experience with the SUPG, Finite Volume and Discontinuous-Galerkin methods. Our objective is to obtain a stable and accurate nite element formulation for multidimensional hyperbolic-parabolic problems with particular emphasis on compressible ows. In the proposed formulati...

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...

O objetivo deste estudo foi análise numérica, via simulação realizado no ANSYS Fluent em um aerofólio de perfil NACA 4415 com variações ângulos ataque. Analisou-se a distribuição pressão e velocidade do fluido ao redor da estrutura, bem como os valores coeficientes arrasto sustentação. Por meio das equações modelo turbulência denominado Spalart-Allmaras possível encontrar as tensões turbulentas...

A computational analysis of an annular converging-diverging (CD) and an altitude adaptive expansion-deflection (ED) nozzle is presented. Numerical results were generated using a 2D axisymmetric, pressure-coupled solver in conjunction with the Spalart-Allmaras turbulence closure model and second order spatial discretisation schemes. Results were recorded over a theoretical altitude range and com...

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...

Aerodynamic shape optimization based on high-fidelity models is a computational intensive endeavor. The majority of the computational time is spent in the flow solver, and in the gradient calculation. In this paper, we present two approaches for reducing the overall computational cost of the optimization. The techniques are tested using the Common Research Model wing benchmark defined by the Ae...

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...