A p-adaptive implicit discontinuous Galerkin method for the under-resolved simulation of compressible turbulent flows

In the last decades Computational Fluid Dynamics has become a widespread practice in several industrial fields, e.g., aerodynamics, aeroacoustic. The growing need of high-fidelity flow simulations for the accurate determination of problem-specific quantities paved the way to higher-order methods such as the discontinuous Galerkin (DG) method. In this context, the industrial interest is strongly promoting the development of more and more efficient high-order CFD solvers. In this work we exploit some techniques, i.e. p-adaptation, quadrature reduction and load balancing, to enhance the computational efficiency of an existing DG code. The accuracy and efficiency of our approach will be assessed by computing the implicit Large Eddy Simulation of the flow past a circular cylinder at Reynolds number Re = 3900, and around a NACA0018 airfoil at Reynolds number Re = 10000 and angle of attack α = 15

Under-resolved simulation of turbulent flows using a p-adaptive discontinuous galerkin method

In this work we present the main features of a p-adaptive Discontinuous Galerkin (DG) method, suited for the accurate and efficient simulation of turbulent flows. The method allows to locally adapt the polynomial degree of the solution within mesh elements (p-adaptation), obtaining significant reduction of the simulation time and memory, and, at the same time, preserving the high accuracy needed by Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES). Adaptation is driven by a simple error indicator, obtained blending two simple indicators based on the interface pressure jumps and on the decay of the coefficients of the modal expansion. Moreover, a load-balancing strategy is adopted during adaptation to achieve good parallel performances. Preliminary results are presented for the under-resolved simulation of the turbulent flows (i) around the NACA 0018 airfoil, Rec = 100 000, M = 0.2 and angle of attack AoA = 10", and (ii) around a rounded leading-edge flat plate (the T3L test case of the ERCOFTAC suite)

A p-adaptive implicit discontinuous Galerkin method for the under-resolved simulation of compressible turbulent flows

In the last decades Computational Fluid Dynamics has become a widespread practice in several industrial fields, e.g., aerodynamics, aeroacoustic. The growing need of high-fidelity flow simulations for the accurate determination of problem-specific quantities paved the way to higher-order methods such as the discontinuous Galerkin (DG) method. In this context, the industrial interest is strongly promoting the development of more and more efficient high-order CFD solvers. In this work we exploit some techniques, i.e. p-adaptation, quadrature reduction and load balancing, to enhance the computational efficiency of an existing DG code. The accuracy and efficiency of our approach will be assessed by computing the implicit Large Eddy Simulation of the flow past a circular cylinder at Reynolds number Re = 3900, and around a NACA0018 airfoil at Reynolds number Re = 10000 and angle of attack α = 15

A p-adaptive implicit discontinuous Galerkin method for the under-resolved simulation of compressible turbulent flows

In the last decades Computational Fluid Dynamics has become a widespread practice in several industrial fields, e.g., aerodynamics, aeroacoustic. The growing need of high-fidelity flow simulations for the accurate determination of problem-specific quantities paved the way to higher-order methods such as the discontinuous Galerkin (DG) method. In this context, the industrial interest is strongly promoting the development of more and more efficient high-order CFD solvers. In this work we exploit some techniques, i.e. p-adaptation, quadrature reduction and load balancing, to enhance the computational efficiency of an existing DG code. The accuracy and efficiency of our approach will be assessed by computing the implicit Large Eddy Simulation of the flow past a circular cylinder at Reynolds number Re = 3900, and around a NACA0018 airfoil at Reynolds number Re = 10000 and angle of attack α = 15

Space Adaptive Methods/Meshing

This chapter describes space adaptive approaches developed by six TILDA partners for the application in scale-resolving simulations. They are designed to provide sufficient spatial resolution in regions where required and to allow a lower resolution elsewhere for efficiency reasons. Adaptation techniques considered include mesh (h-refinement), order refinement of the spatial discretization (p-refinement) or a combination of both (hp-refinement). Furthermore, near-wall local mesh refinement, refinement using feature-based indicators and indicators obtained from the Variational Multiscale Method are considered

Space Adaptive Methods/Meshing

This chapter describes space adaptive approaches developed by six TILDA partners for the application in scale-resolving simulations. They are designed to provide sufficient spatial resolution in regions where required and to allow a lower resolution elsewhere for efficiency reasons. Adaptation techniques considered include mesh (h-refinement), order refinement of the spatial discretization (p-refinement) or a combination of both (hp-refinement). Furthermore, near-wall local mesh refinement, refinement using feature-based indicators and indicators obtained from the Variational Multiscale Method are considered