[gtc]

Hi, everyone.

I am a newer. I have learnt about simulating pitch and plunge airfoil using SU2( ver7.3.1 blackbird ) as shown in the test cases.

However, I was worrying wheather it can extend to wing (3D) in pitch and plunge motion directly. How should I adjust the follwing options:

% Pitching angular freq. (rad/s) about the motion origin
PITCHING_OMEGA= 0.0 0.0 0.0
%
% Pitching amplitude (degrees) about the motion origin
PITCHING_AMPL= 0.0 0.0 0.0
%
% Pitching phase offset (degrees) about the motion origin
PITCHING_PHASE= 0.0 0.0 0.0
%
% Translational velocity (m/s or ft/s) in the x, y, & z directions
TRANSLATION_RATE = 0.0 0.0 0.0
%
% Plunging angular freq. (rad/s) in x, y, & z directions
PLUNGING_OMEGA= 0.0 0.0 0.0
%
% Plunging amplitude (m or ft) in x, y, & z directions
PLUNGING_AMPL= 0.0 0.0 0.0

For example, if it is wanted to pitch around axis y=0.3, with pitch frequency w=3 and plunge frequency w=5, how could i adjust. (It seems that the options in config_template.cfg are only suitable for 2D airfoil).

If it can not simulate pitch and plunge 3D wing by the above way directly, how could i realize my task by other accessible method with SU2.

I really appreciate any help you can provide.

[bigfootedrockmidget]

Hi,
There is an example of the (optimization of the) pitching Onera M6 wing in the TestCases folder in optimization_euler/pitching_oneram6

[gtc]

Thank you very much. I have got it.

When I learn more about it, there still exist several questions:

(1) In the file config_template.cfg, it provides some types for dynamic surface movement (NONE, DEFORMING, MOVING_WALL, AEROELASTIC, AEROELASTIC_RIGID_MOTION, EXTERNAL, EXTERNAL_ROTATION). What troubles me is that what are the differences between the AEROELASTIC and AEROELASTIC_RIGID_MOTION? What sub-options follow them, respectively? If they are activated, does it mean wing moves and deforms by aerodynamic forces, other than forced amplitude and frequency in the pitch and plunge?

(2) I find that SU2 is able to simulate flutter for 2D airfoil and realize it with specified options, just like this

% -------------- AEROELASTIC SIMULATION (Typical Section Model) ---------------%
%
% Activated by GRID_MOVEMENT_KIND option
%
% The flutter speed index (modifies the freestream condition in the solver)
FLUTTER_SPEED_INDEX = 0.6
%
% Natural frequency of the spring in the plunging direction (rad/s)
PLUNGE_NATURAL_FREQUENCY = 100
%
% Natural frequency of the spring in the pitching direction (rad/s)
PITCH_NATURAL_FREQUENCY = 100
%
% The airfoil mass ratio
AIRFOIL_MASS_RATIO = 60
%
% Distance in semichords by which the center of gravity lies behind
% the elastic axis
CG_LOCATION = 1.8
%
% The radius of gyration squared (expressed in semichords)
% of the typical section about the elastic axis
RADIUS_GYRATION_SQUARED = 3.48
%
% Solve the aeroelastic equations every given number of internal iterations
AEROELASTIC_ITER = 3

It has an example in the testcase. Is there an example for 3D wing flutter with two freedom pitch and plunge? How can I select options and adjust them for 3D wing flutter with two freedom pitch and plunge, correct and complete?

[gtc]

Originally Posted by gtc

Thank you very much. I have got it.

When I learn more about it, there still exist several questions:

(1) In the file config_template.cfg, it provides some types for dynamic surface movement (NONE, DEFORMING, MOVING_WALL, AEROELASTIC, AEROELASTIC_RIGID_MOTION, EXTERNAL, EXTERNAL_ROTATION). What troubles me is that what are the differences between the AEROELASTIC and AEROELASTIC_RIGID_MOTION? What sub-options follow them, respectively? If they are activated, does it mean wing moves and deforms by aerodynamic forces, other than forced amplitude and frequency in the pitch and plunge?

(2) I find that SU2 is able to simulate flutter for 2D airfoil and realize it with specified options, just like this

% -------------- AEROELASTIC SIMULATION (Typical Section Model) ---------------%
%
% Activated by GRID_MOVEMENT_KIND option
%
% The flutter speed index (modifies the freestream condition in the solver)
FLUTTER_SPEED_INDEX = 0.6
%
% Natural frequency of the spring in the plunging direction (rad/s)
PLUNGE_NATURAL_FREQUENCY = 100
%
% Natural frequency of the spring in the pitching direction (rad/s)
PITCH_NATURAL_FREQUENCY = 100
%
% The airfoil mass ratio
AIRFOIL_MASS_RATIO = 60
%
% Distance in semichords by which the center of gravity lies behind
% the elastic axis
CG_LOCATION = 1.8
%
% The radius of gyration squared (expressed in semichords)
% of the typical section about the elastic axis
RADIUS_GYRATION_SQUARED = 3.48
%
% Solve the aeroelastic equations every given number of internal iterations
AEROELASTIC_ITER = 3

It has an example in the testcase. Is there an example for 3D wing flutter with two freedom pitch and plunge? How can I select options and adjust them for 3D wing flutter with two freedom pitch and plunge, correct and complete?

Here is the question(3)

When I want to restart the simulation in the TestCases/aeroelastic/aeroelastic_NACA64A010, it fails and ask for "There is no flow restart file restart_flow_00017.csv". However, the current settings are

OUTPUT_FILES= (RESTART)
READ_BINARY_RESTART= YES

Why it still calls for ***.csv file, other than restarting with ***.dat files?

When I adjust by follows:

OUTPUT_FILES= (RESTART_ASCII)
READ_BINARY_RESTART= NO

It restarts well. So does it mean it has to output ASCII files for restarting in simulating aeroelastic?