Recover moments to output force/mom coefficients at ref state

sharpy/linear/utils/derivatives.py

@@ -7,13 +7,19 @@
 class Derivatives:
     """
     Class containing the derivatives set for a given state-space system (i.e. aeroelastic or aerodynamic)
+
+    Args:
+        reference_dimensions (dict): Info on the reference dimensions ``S_ref`` (area) ``b_ref`` (span) ``c_ref`` chord
+          ``u_inf`` velocity and ``rho`` density
+        static_state (tuple): Force and moment coefficient at the reference state (dim6) (inertial frame)
+        target_system (str): Name of target system ``aeroelastic`` or ``aerodynamic``
     """
     def __init__(self, reference_dimensions, static_state, target_system=None):
 
         self.target_system = target_system  # type: str # name of target system (aerodynamic/aeroelastic)
         self.transfer_function = None  # type: np.array # matrix of steady-state TF for target system
 
-        self.static_state = static_state  # type: tuple # [fx, fy, fz] at ref state
+        self.static_state = static_state  # type: tuple # [fx, fy, fz, mx, my, mz] at ref state
         self.reference_dimensions = reference_dimensions  # type: dict # name: ref_dimension_value dictionary
 
         self.separator = '\n' + 80 * '#' + '\n'
@@ -33,6 +39,8 @@ def __init__(self, reference_dimensions, static_state, target_system=None):
                              'force_angular_vel': self.dynamic_pressure * s_ref * c_ref / u_inf,
                              'moment_lon_angular_vel': self.dynamic_pressure * s_ref * c_ref * c_ref / u_inf}  # missing rates
 
+        # only used to show the forces/moment coefficient at ref state
+        # for derivatives calculation the vectors at the linearisation ref are used
         self.steady_coefficients = np.array(self.static_state)
         self.steady_coefficients[:3] /= self.coefficients['force']
         self.steady_coefficients[3] /= self.coefficients['moment_lat']

sharpy/postproc/stabilityderivatives.py

@@ -9,7 +9,16 @@
 @solver_interface.solver
 class StabilityDerivatives(solver_interface.BaseSolver):
     """
-    Outputs the stability derivatives of a free-flying aircraft
+    Outputs the stability derivatives of a free-flying aircraft.
+
+    The simulation set-up to obtain the stability derivatives is not standard, and requires specific settings
+    in the solvers ran prior to this post-processor. Please see the tutorial at:
+    https://github.com/ngoiz/hale-ders/blob/main/Delivery/01_StabilityDerivatives/01_StabilityDerivatives.ipynb
+
+    In the future, a routine will be available where these required solvers' settings are pre-populated
+
+    Note:
+        Requires the AeroForcesCalculator post-processor to have been run before.
 
     """
     solver_id = 'StabilityDerivatives'
@@ -213,13 +222,10 @@ def get_state_space(self, target_system):
         return ss
 
     def steady_aero_forces(self):
-        """Retrieve steady aerodynamic forces at the linearisation reference
+        """Retrieve steady aerodynamic forces and moments at the linearisation reference at the
 
         Returns:
-            tuple: (fx, fy, fz) in the inertial G frame
+            tuple: (fx, fy, fz, mx, my, mz) in the inertial G frame
         """
-        fx = np.sum(self.data.linear.tsaero0.inertial_steady_forces[:, 0], 0)
-        fy = np.sum(self.data.linear.tsaero0.inertial_steady_forces[:, 1], 0)
-        fz = np.sum(self.data.linear.tsaero0.inertial_steady_forces[:, 2], 0)
 
-        return fx, fy, fz
+        return self.data.linear.tsaero0.total_steady_inertial_forces