Experiments with Hermite Methods for Simulating Compressible Flows: Runge-Kutta Time-Stepping and Absorbing Layers

Author(s):  
Thomas Hagstrom ◽  
Daniel Appelo
1991 ◽  
Vol 25 (3) ◽  
pp. 243-263 ◽  
Author(s):  
J. W. van der Burg ◽  
J. G. M. Kuerten ◽  
P. J. Zandbergen

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Sibo Li ◽  
Roberto Paoli ◽  
Michael D’Mello

Compressible density-based solvers are widely used in OpenFOAM, and the parallel scalability of these solvers is crucial for large-scale simulations. In this paper, we report our experiences with the scalability of OpenFOAM’s native rhoCentralFoam solver, and by making a small number of modifications to it, we show the degree to which the scalability of the solver can be improved. The main modification made is to replace the first-order accurate Euler scheme in rhoCentralFoam with a third-order accurate, four-stage Runge-Kutta or RK4 scheme for the time integration. The scaling test we used is the transonic flow over the ONERA M6 wing. This is a common validation test for compressible flows solvers in aerospace and other engineering applications. Numerical experiments show that our modified solver, referred to as rhoCentralRK4Foam, for the same spatial discretization, achieves as much as a 123.2% improvement in scalability over the rhoCentralFoam solver. As expected, the better time resolution of the Runge–Kutta scheme makes it more suitable for unsteady problems such as the Taylor–Green vortex decay where the new solver showed a 50% decrease in the overall time-to-solution compared to rhoCentralFoam to get to the final solution with the same numerical accuracy. Finally, the improved scalability can be traced to the improvement of the computation to communication ratio obtained by substituting the RK4 scheme in place of the Euler scheme. All numerical tests were conducted on a Cray XC40 parallel system, Theta, at Argonne National Laboratory.


2016 ◽  
Vol 9 (1) ◽  
pp. 87-110 ◽  
Author(s):  
Jianming Liu ◽  
Jianxian Qiu ◽  
Mikhail Goman ◽  
Xinkai Li ◽  
Meilin Liu

AbstractIn order to suppress the failure of preserving positivity of density or pressure, a positivity-preserving limiter technique coupled withh-adaptive Runge-Kutta discontinuous Galerkin (RKDG) method is developed in this paper. Such a method is implemented to simulate flows with the large Mach number, strong shock/obstacle interactions and shock diffractions. The Cartesian grid with ghost cell immersed boundary method for arbitrarily complex geometries is also presented. This approach directly uses the cell solution polynomial of DG finite element space as the interpolation formula. The method is validated by the well documented test examples involving unsteady compressible flows through complex bodies over a large Mach numbers. The numerical results demonstrate the robustness and the versatility of the proposed approach.


2015 ◽  
Vol 37 (2) ◽  
pp. A747-A775 ◽  
Author(s):  
Marcus J. Grote ◽  
Michaela Mehlin ◽  
Teodora Mitkova

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