CFD Simulations AC7-02: Difference between revisions

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The details of the numerical tests are given in the following paragraphs.  
The details of the numerical tests are given in the following paragraphs.  
In summary, the main differences between the simulations are:
In summary, the main differences between the simulations are:
<br/>
1. '''Computational meshes''': LES1&2 employ the same comp. meshes, whereas LES3 and RANS use different meshes.
1. '''Computational meshes''': LES1&2 employ the same comp. meshes, whereas LES3 and RANS use different meshes.
<br/>
2. '''Turbulence modeling''': LES1 uses the dynamic version of the Smagorinsky-Lilly subgrid scale model, whereas LES2&3 employ the Wall-adapting eddy viscosity (WALE) SGS model.  
2. '''Turbulence modeling''': LES1 uses the dynamic version of the Smagorinsky-Lilly subgrid scale model, whereas LES2&3 employ the Wall-adapting eddy viscosity (WALE) SGS model.  
In RANS simulations, the k-ω SST, standard k-ε and RNG k-ε turbulence model have been tested.
In RANS simulations, the k-ω SST, standard k-ε and RNG k-ε turbulence model have been tested.
<br/>
3. '''Discretisation method''': LES1&2 and RANS use the Finite Volume approach whereas LES3 employs the Finite Element Method.
3. '''Discretisation method''': LES1&2 and RANS use the Finite Volume approach whereas LES3 employs the Finite Element Method.



Revision as of 15:14, 17 May 2020

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

Airflow in the human upper airways

Application Challenge AC7-02   © copyright ERCOFTAC 2020

CFD Simulations

Overview of CFD Simulations

Three LES (LES1-3) and one RANS simulation were carried out in the benchmark geometry at an air flowrate of 60 L/min. This flowrate results in a Reynolds number of 4921 in the model’s trachea. This is slightly higher than the Reynolds number in the experiments, due to the reasons discussed in section 2.4. The details of the numerical tests are given in the following paragraphs. In summary, the main differences between the simulations are:
1. Computational meshes: LES1&2 employ the same comp. meshes, whereas LES3 and RANS use different meshes.
2. Turbulence modeling: LES1 uses the dynamic version of the Smagorinsky-Lilly subgrid scale model, whereas LES2&3 employ the Wall-adapting eddy viscosity (WALE) SGS model. In RANS simulations, the k-ω SST, standard k-ε and RNG k-ε turbulence model have been tested.
3. Discretisation method: LES1&2 and RANS use the Finite Volume approach whereas LES3 employs the Finite Element Method.

Large Eddy Simulations — Case LES1

Computational domain and meshes

Solution strategy and boundary conditions — Airflow

Numerical accuracy

Large Eddy Simulations — Case LES2

Computational domain and meshes

Solution strategy and boundary conditions — Airflow

Numerical accuracy

Large Eddy Simulations — Case LES3

Computational domain and meshes

Solution strategy and boundary conditions — Airflow

Numerical accuracy

RANS Simulations

Computational domain and meshes

Solution strategy and boundary conditions — Airflow

Numerical accuracy




Contributed by: P. Koullapisa, J. Muelab, O. Lehmkuhlc, F. Lizald, J. Jedelskyd, M. Jichad, T. Jankee, K. Bauere, M. Sommerfeldf, S. C. Kassinosa — 
aDepartment of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
bHeat and Mass Transfer Technological Centre, Universitat Politècnica de Catalunya, Terrassa, Spain
cBarcelona Supercomputing center, Barcelona, Spain
dFaculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
eInstitute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg, Germany
fInstitute Process Engineering, Otto von Guericke University, Halle (Saale), Germany

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

© copyright ERCOFTAC 2020