Accuracy and performance evaluation of low density internal and external flow predictions using CFD and DSMC
Publication date
2024-06-18
Document type
Forschungsartikel
Author
Samanta, Amit K.
Küpper, Jochen
Amin, Muhamed
Organisational unit
DASHH Graduate School for the Structure of Matter
ISSN
Series or journal
Computers & Fluids
Periodical volume
279
Peer-reviewed
✅
Part of the university bibliography
✅
Keyword
DSMC
SPARTA
Continuum assumption
Transition regime
Rarefied flow
High-performance computing
Abstract
The Direct Simulation Monte Carlo (DSMC) method was widely used to simulate low density gas flows with large Knudsen numbers. However, DSMC encounters limitations in the regime of lower Knudsen numbers (Kn<0.05). In such cases, approaches from classical computational fluid dynamics (CFD) relying on the continuum assumption are preferred, offering accurate solutions at acceptable computational costs. In experiments aimed at imaging aerosolized nanoparticles in vacuo a wide range of Knudsen numbers occur, which motivated the present study on the analysis of the advantages and drawbacks of DSMC and CFD simulations of rarefied flows in terms of accuracy and computational effort. Furthermore, the potential of hybrid methods is evaluated. For this purpose, DSMC and CFD simulations of the flow inside a convergent–divergent nozzle (internal expanding flow) and the flow around a conical body (external shock generating flow) were carried out. CFD simulations utilize the software OpenFOAM and the DSMC solution is obtained using the software SPARTA. The results of these simulation techniques are evaluated by comparing them with experimental data (1), evaluating the time-to-solution (2) and the energy consumption (3), and assessing the feasibility of hybrid CFD-DSMC approaches (4).
Version
Published version
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