[Sakun]

Hi,


I am trying to validate NACA0012 using my own C-H mesh with AOA of 6 degrees. Created the 2D mesh using ICEM and output the mesh in CGNS format (NACA0012_Mesh attachment).
I have named the geometry/Mesh as below,


INLET= velocity inlet
TOP, BOTTOM = symmetry
OUTLET= pressure outlet
AIRFOIL= wall
(Geo attachment)

When I am trying to run the simulation, I’m getting “SU2 has diverged (NaN detected)” error (Error attachment).


As a way to identify the problem location, I have specified INLET, TOP and BOTTOM under Fairfield boundary condition (because in SU2 tutorials and test cases they have always used farfield boundary condition), then simulation runs but with unrealistic results.
This how I have specified the velocity inlet boundary flow conditions,

% -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
%
% Navier-Stokes wall boundary marker(s) (NONE = no marker)
MARKER_HEATFLUX= ( AIRFOIL, 0.0 )
%
% Far-field boundary marker(s) (NONE = no marker)
MARKER_INLET= ( INLET,300.0 ,30.0 ,0.0 ,0.0 ,0.0 , )
INC_INLET_TYPE= VELOCITY_INLET
%
MARKER_OUTLET= ( OUTLET, 101325.0, )
INC_OUTLET_TYPE= PRESSURE_OUTLET

MARKER_SYM= ( TOP, BOTTOM )
% Marker(s) of the surface to be plotted or designed
MARKER_PLOTTING= ( AIRFOIL )
%
% Marker(s) of the surface where the functional (Cd, Cl, etc.) will be evaluated
MARKER_MONITORING= ( AIRFOIL )

Below is my initial flow conditions,

% ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
%
FLUID_MODEL= INC_IDEAL_GAS
% AoA 10 deg
%INC_VELOCITY_INIT= ( 29.835, 3.135, 0.0 )
%
% Non-dimensionalization scheme for incompressible flows. Options are
% INITIAL_VALUES (default), REFERENCE_VALUES, or DIMENSIONAL.
% INC_*_REF values are ignored unless REFERENCE_VALUES is chosen.
INC_NONDIM= INITIAL_VALUES
% Solve the energy equation in the incompressible flow solver
INC_ENERGY_EQUATION= YES
%
% Initial density for incompressible flows
% (1.2886 kg/m^3 by default (air), 998.2 Kg/m^3 (water))
INC_DENSITY_INIT= 1.2886
%
% Initial velocity for incompressible flows (1.0,0,0 m/s by default)
% AoA 0.0 deg
INC_VELOCITY_INIT= ( 30.0, 0.0, 0.0 )
%
% Initial temperature for incompressible flows that include the
% energy equation (288.15 K by default). Value is ignored if
% INC_ENERGY_EQUATION is false.
INC_TEMPERATURE_INIT= 300
%
% Reference density for incompressible flows (1.0 kg/m^3 by default)
INC_DENSITY_REF= 1.0
%
% Reference velocity for incompressible flows (1.0 m/s by default)
INC_VELOCITY_REF= 1.0
%
% Reference temperature for incompressible flows that include the
% energy equation (1.0 K by default)
  INC_TEMPERATURE_REF= 1.0

So I guess I have specified boundary conditions wrong for a velocity, can someone guide me on this ?


Much appreciate,

[bigfootedrockmidget]

I think symmetry is not a suitable boundary condition here. It is probably best to use far field boundary conditions for the entire surrounding boundary.
You can have a look at the setup in the testcases repository here:
https://github.com/su2code/SU2/tree/..._rans/naca0012
together with the mesh:

https://github.com/su2code/TestCases..._rans/naca0012


Which is similar to your C-type mesh.

[Sakun]

Hi,

Many thanks for helping me out to learn my mistakes, was abled to run the simulation and validate against AOA 10 (cP Validation attachment).


The main issue I think, I have overcomplicated fluent case set up with the SU2 case set up.


Also, what is the meaning of NaN detected in “SU2 has diverged (NaN detected)” error message?