Skip to content

fix turbulence intensity value, divided by 100 #85

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 22, 2022
Merged

fix turbulence intensity value, divided by 100 #85

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions _tutorials/compressible_flow/Transitional_Flat_Plate/Transitional_Flat_Plate.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,7 @@ For verification, we will be comparing SU2 results against the results of natura

### Problem Setup

The length of the flat plate is 1.5 meters, and it is represented by an adiabatic no-slip wall boundary condition. There is a symmetry plane located before the leading edge of the flat plate. Inlet boundary condition is used on the left boundary of the domain, and outlet boundary condition is applied to the top and right boundaries of the domain. The freestream velocity, density, viscosity and turbulence intensity (%) is specified as 50.1 m/s, 1.2 kg/m^3, 1.8e-05 and 0.18%, respectively. Since the Mach number is about 0.15, compressibility effects are negligible; therefore, the incompressible flow solver can be employed.
The length of the flat plate is 1.5 meters, and it is represented by an adiabatic no-slip wall boundary condition. There is a symmetry plane located before the leading edge of the flat plate. Inlet boundary condition is used on the left boundary of the domain, and outlet boundary condition is applied to the top and right boundaries of the domain. The freestream velocity, density, viscosity and turbulence intensity (%) is specified as 50.1 m/s, 1.2 kg/m^3, 1.8e-05 and 0.18% (u'/U=0.0018), respectively. Since the Mach number is about 0.15, compressibility effects are negligible; therefore, the incompressible flow solver can be employed.

### Mesh Description

Expand All @@ -68,8 +68,8 @@ KIND_TURB_MODEL= SA
% Specify transition model (NONE, BC)
KIND_TRANS_MODEL= BC
%
% Specify Turbulence Intensity (%)
FREESTREAM_TURBULENCEINTENSITY = 0.18
% Specify Turbulence Intensity (u'/U)
FREESTREAM_TURBULENCEINTENSITY = 0.0018
```

The governing equations are RANS with the Spalart-Allmaras (`SA`) turbulence model. By entering `KIND_TRANS_MODEL= BC`, the Bas-Cakmakcioglu Algebraic Transition Model is activated. This model requires freestream turbulence intensity that is to be used in the transition correlation, thus the `FREESTREAM_TURBULENCEINTENSITY` option is also used. The BC model achieves its purpose by modifying the production term of the 1-equation SA turbulence model. The production term of the SA model is damped until a considerable amount of turbulent viscosity is generated, and after that point, the damping effect on the transition model is disabled. Thus, a transition from laminar to turbulent flow is obtained.
Expand Down