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Probing double-distribution-function models in discrete-velocity Boltzmann methods for highly compressible flows:
S A Hosseini1, A Bhadauria1, I V Karlin1
1Department of Mechanical and Process Engineering, <a href="https://ror.org/05a28rw58">ETH Zurich</a>, 8092 Zurich, Switzerland.
Physical Review. E
|November 20, 2024
Summary
The double distribution function approach offers efficient kinetic solvers for compressible flows. The total energy split method provides optimal performance for high-speed flows, balancing accuracy and computational cost.
Area of Science:
- Computational fluid dynamics
- Kinetic theory
- High-speed compressible flows
Background:
- Kinetic solvers are extended to compressible flows using the double distribution function approach.
- Various realizations and energy partition strategies exist for this method.
Purpose of the Study:
- To present an overview and comparative study of double distribution function realizations for high-speed compressible flows.
- To analyze different energy partition strategies, hydrodynamic limits, and numerical performance.
Main Methods:
- Comparative analysis of three energy partition strategies: nontranslational, internal, and total energy splits.
- Numerical study of accuracy and performance using the particles on demand realization.
- Analysis of hydrodynamic limits and quadrature requirements.
Main Results:
- The nontranslational energy split requires higher-order quadrature for Navier-Stokes-Fourier equation recovery.
- The internal energy split recovers the hydrodynamic limit but introduces nonlocal source terms, increasing computational cost.
- The total energy split demonstrates optimal overall performance in terms of accuracy and efficiency.
Conclusions:
- The total energy split is the most effective strategy for high-speed compressible flows within the double distribution function approach.
- Careful consideration of energy partition is crucial for balancing accuracy and computational demands in kinetic solvers.
- This study provides valuable insights for selecting and implementing kinetic solvers for complex fluid dynamics problems.
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