SAM
https://sam.ensam.eu:443
The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Tue, 06 Jun 2023 12:28:09 GMT2023-06-06T12:28:09ZOn the scalability of CFD tool for supersonic jet flow configurations
http://hdl.handle.net/10985/18277
On the scalability of CFD tool for supersonic jet flow configurations
JUNQUEIRA-JUNIOR, Carlos; AZEVEDO, João Luiz F.; PANETTA, Jairo; WOLF, William R.; YAMOUNI, Sami
New regulations are imposing noise emissions limitations for the aviation industry which are pushing researchers and engineers to invest efforts in studying the aeroacoustics phenomena. Following this trend, an in-house computational fluid dynamics tool is build to reproduce high fidelity results of supersonic jet flows for aeroacoustic analogy applications. The solver is written using the large eddy simulation formulation that is discretized using a finite difference approach and an explicit time integration. Numerical simulations of supersonic jet flows are very expensive and demand efficient high-performance computing. Therefore, non-blocking message passage interface protocols and parallel Input/Output features are implemented into the code in order to perform simulations which demand up to one billion grid points. The present work addresses the evaluation of code improvements along with the computational performance of the solver running on a computer with maximum theoretical peak of 2.727 PFlops. Different mesh configurations, whose size varies from a few hundred thousand to approximately one billion grid points, are evaluated in the present paper. Calculations are performed using different workloads in order to assess the strong and weak scalability of the parallel computational tool. Moreover, validation results of a realistic flow condition are also presented in the current work.
Wed, 01 Jan 2020 00:00:00 GMThttp://hdl.handle.net/10985/182772020-01-01T00:00:00ZJUNQUEIRA-JUNIOR, CarlosAZEVEDO, João Luiz F.PANETTA, JairoWOLF, William R.YAMOUNI, SamiNew regulations are imposing noise emissions limitations for the aviation industry which are pushing researchers and engineers to invest efforts in studying the aeroacoustics phenomena. Following this trend, an in-house computational fluid dynamics tool is build to reproduce high fidelity results of supersonic jet flows for aeroacoustic analogy applications. The solver is written using the large eddy simulation formulation that is discretized using a finite difference approach and an explicit time integration. Numerical simulations of supersonic jet flows are very expensive and demand efficient high-performance computing. Therefore, non-blocking message passage interface protocols and parallel Input/Output features are implemented into the code in order to perform simulations which demand up to one billion grid points. The present work addresses the evaluation of code improvements along with the computational performance of the solver running on a computer with maximum theoretical peak of 2.727 PFlops. Different mesh configurations, whose size varies from a few hundred thousand to approximately one billion grid points, are evaluated in the present paper. Calculations are performed using different workloads in order to assess the strong and weak scalability of the parallel computational tool. Moreover, validation results of a realistic flow condition are also presented in the current work.Strong scaling of numerical solver for supersonic jet flow configurations
http://hdl.handle.net/10985/17676
Strong scaling of numerical solver for supersonic jet flow configurations
JUNQUEIRA-JUNIOR, Carlos; AZEVEDO, João Luiz F.; PANETTA, Jairo; WOLF, William R.; YAMOUNI, Sami
Acoustics loads are rocket design constraints which push researches and engineers to invest efforts in the aeroacoustics phenomena which is present on launch vehicles. Therefore, an in-house computational fluid dynamics tool is developed in order to reproduce high-fidelity results of supersonic jet flows for aeroacoustic analogy applications. The solver is written using the large eddy simulation formulation that is discretized using a finite-difference approach and an explicit time integration. Numerical simulations of supersonic jet flows are very expensive and demand efficient high-performance computing. Therefore, non-blocking message passage interface protocols and parallel input/output features are implemented into the code in order to perform simulations which demand up to one billion degrees of freedom. The present work evaluates the parallel efficiency of the solver when running on a supercomputer with a maximum theoretical peak of 127.4 TFLOPS. Speedup curves are generated using nine different workloads. Moreover, the validation results of a realistic flow condition are also presented in the current work.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10985/176762019-01-01T00:00:00ZJUNQUEIRA-JUNIOR, CarlosAZEVEDO, João Luiz F.PANETTA, JairoWOLF, William R.YAMOUNI, SamiAcoustics loads are rocket design constraints which push researches and engineers to invest efforts in the aeroacoustics phenomena which is present on launch vehicles. Therefore, an in-house computational fluid dynamics tool is developed in order to reproduce high-fidelity results of supersonic jet flows for aeroacoustic analogy applications. The solver is written using the large eddy simulation formulation that is discretized using a finite-difference approach and an explicit time integration. Numerical simulations of supersonic jet flows are very expensive and demand efficient high-performance computing. Therefore, non-blocking message passage interface protocols and parallel input/output features are implemented into the code in order to perform simulations which demand up to one billion degrees of freedom. The present work evaluates the parallel efficiency of the solver when running on a supercomputer with a maximum theoretical peak of 127.4 TFLOPS. Speedup curves are generated using nine different workloads. Moreover, the validation results of a realistic flow condition are also presented in the current work.External Laminar Boundary Layer Simulations Using a High-Fidelity Wall-Modeling Approach
http://hdl.handle.net/10985/23662
External Laminar Boundary Layer Simulations Using a High-Fidelity Wall-Modeling Approach
VIANA DAURICIO, Eron Tiago; JUNQUEIRA JUNIOR, Carlos; FEROLLA DE ABREU, Diego; AZEVEDO, João Luiz F.
Wall-Modeled Large Eddy Simulation (WMLES) is a well-stablished technique for obtaining high-fidelity solutions of turbulent, high Reynolds number flows, with reasonably acceptable computational costs. However, for external flows, the very thin laminar boundary layer developing near the body leading edge imposes quite restrictive mesh resolution requirements, leading to prohibitively high computational costs for practical Reynolds numbers. We propose a wall-modeling approach for the laminar portion of the boundary layer in order to alleviate these costs by reducing the aforementioned mesh resolution requirements. The wall model is based on local self-similar solutions of the boundary layer, and is implemented in the same context of wall-stress models in the WMLES approach. An assessment of the model is done in terms of both pressure and skin friction coefficient distributions along the surface, for an incompressible, fully laminar flow around a NACA 0012 airfoil geometry, with a chord Reynolds number of Re_c = 4500. The results obtained in the simulations using the proposed model are in good agreement with the reference solution, demonstrating the feasibility of the model for external laminar flows.
Tue, 01 Nov 2022 00:00:00 GMThttp://hdl.handle.net/10985/236622022-11-01T00:00:00ZVIANA DAURICIO, Eron TiagoJUNQUEIRA JUNIOR, CarlosFEROLLA DE ABREU, DiegoAZEVEDO, João Luiz F.Wall-Modeled Large Eddy Simulation (WMLES) is a well-stablished technique for obtaining high-fidelity solutions of turbulent, high Reynolds number flows, with reasonably acceptable computational costs. However, for external flows, the very thin laminar boundary layer developing near the body leading edge imposes quite restrictive mesh resolution requirements, leading to prohibitively high computational costs for practical Reynolds numbers. We propose a wall-modeling approach for the laminar portion of the boundary layer in order to alleviate these costs by reducing the aforementioned mesh resolution requirements. The wall model is based on local self-similar solutions of the boundary layer, and is implemented in the same context of wall-stress models in the WMLES approach. An assessment of the model is done in terms of both pressure and skin friction coefficient distributions along the surface, for an incompressible, fully laminar flow around a NACA 0012 airfoil geometry, with a chord Reynolds number of Re_c = 4500. The results obtained in the simulations using the proposed model are in good agreement with the reference solution, demonstrating the feasibility of the model for external laminar flows.