[FluidDynamics] Add process to compute aerodynamic force & moment coefficients from nodal reactions

[juancamarotti]

Summary

This PR adds a new C++ process to compute aerodynamic force and moment coefficients from nodal REACTIONs on a given ModelPart.
The aerodynamic load is consistently taken as -REACTION and projected onto wind axes defined by angle of attack α and sideslip β.

The following ModelPart coefficients are computed and stored:

• LIFT_COEFFICIENT (CL)
• DRAG_COEFFICIENT (CD)
• LATERAL_FORCE_COEFFICIENT (CY)
• ROLLING_MOMENT_COEFFICIENT (Cl)
• PITCHING_MOMENT_COEFFICIENT (Cm)
• YAWING_MOMENT_COEFFICIENT (Cn)

Usage

Example parameters:

{
  "model_part_name"             : "FluidModelPart.wet_surface",
  "reference_surface"           : 1.0,
  "reference_chord"             : 1.0,
  "reference_span"              : 1.0,
  "moment_reference_point"      : [0.0, 0.0, 0.0],
  "freestream_dynamic_pressure" : 245.0,
  "angle_of_attack"             : 5.0,
  "sideslip_angle"              : 2.0
}

[rubenzorrilla]

This duplicates the compute_drag_process.py. I'd be in favor of extending that with the capabilities in here rather than duplicating them.

EDIT: Note that current implementation works both with body-fitted and unfitted discretizations.

[juancamarotti]

This duplicates the compute_drag_process.py. I'd be in favor of extending that with the capabilities in here rather than duplicating them.

EDIT: Note that current implementation works both with body-fitted and unfitted discretizations.

I was checking this compute_drag_process.py and this is intended to be a base class, isn't it? Having said this, do you propose to create a new process for the computation of the aerodynamic coefficients derived from this base class or how would you do it? @rubenzorrilla

[rubenzorrilla]

This duplicates the compute_drag_process.py. I'd be in favor of extending that with the capabilities in here rather than duplicating them.
EDIT: Note that current implementation works both with body-fitted and unfitted discretizations.

I was checking this compute_drag_process.py and this is intended to be a base class, isn't it? Having said this, do you propose to create a new process for the computation of the aerodynamic coefficients derived from this base class or how would you do it? @rubenzorrilla

My suggestion would be to extend current one to include your stuff, which I think will be very useful. Then we can rename current class and have a deprecated one interfacing the new to avoid breaking backwards compatibility and GUIs. Maybe it's easier to arrange a short meeting to discuss it. Send me an email if you also think so.

[juancamarotti]

@rubenzorrilla I have changed this PR to a draft and I will implement the already discussed changes in another branch