Merge branch 'develop' into enh/draw-motors

docs/user/positions.rst

@@ -58,7 +58,7 @@ And with ``coordinate_system_orientation = nose_to_tail``:
 
 .. important::
 
-  - The coordinate system origin is the point where the axis intersect. This
+  - The coordinate system origin is the point where the axes intersect. This
     point is not explicitly specified and can be chosen by the user. All 
     positions given by the user must be relative to this point.
   - The coordinate system origin does not need to be inside the rocket. It can
@@ -102,13 +102,13 @@ the coordinate system origin at the center of mass without motor:
 
 .. important::
 
-  - The coordinate system origin is at the tip of the nose cone. This point is
-    not explicitly specified and can be chosen by the user. All positions given
-    by the user must be relative to this point.
-  - Since the coordinate system origin is at the tip of the nose cone, the
-    position of the nose cone is **zero**. 
-  - We are using the ``nose_to_tail`` coordinate system orientation. This means
-    that the ``center_of_mass_without_motor`` is positive.
+  - The coordinate system origin is at the center of mass without motor. This
+    point is not explicitly specified and can be chosen by the user. All
+    positions given by the user must be relative to this point.
+  - Since the coordinate system origin is at the center of mass without motor,
+    the position of the ``center_of_mass_without_motor`` is **zero**.
+  - We are using the ``tail_to_nose`` coordinate system orientation. This means
+    that the position of the nose cone is positive.
 
 .. _addsurface:
 
@@ -226,15 +226,15 @@ an arbitrary point and the
 
 .. note::
 
-  Liquid motors are do not have the ``grains_center_of_mass_position`` parameter.
+  Liquid motors do not have the ``grains_center_of_mass_position`` parameter.
 
 .. figure:: ../static/positions/nozzletocomb.png
   :align: center
   :alt: Rocket coordinate system origin
 
 .. note::
 
-  We have, in this case:
+  In this case:
 
   - ``nozzle_position`` is negative.
   - ``grains_center_of_mass_position`` is negative.
@@ -248,15 +248,15 @@ And with ``coordinate_system_orientation = combustion_chamber_to_nozzle``:
 
 .. note::
 
-  We have, in this case:
+  In this case:
 
   - ``nozzle_position`` is positive.
   - ``grains_center_of_mass_position`` is positive.
   - ``center_of_dry_mass_position`` is positive.
 
 .. important::
 
-  - The coordinate system origin is the point where the axis intersect. This
+  - The coordinate system origin is the point where the axes intersect. This
     point is not explicitly specified and can be chosen by the user. All 
     positions given by the user must be relative to this point.
   - The coordinate system origin does not need to be outside the motor. It can

rocketpy/motors/motor.py

@@ -439,6 +439,8 @@ def total_mass_flow_rate(self):
         - The ``LiquidMotor`` class favors the more accurate data from the
           Tanks's mass flow rates. Therefore this value is numerically
           independent of the ``LiquidMotor.mass_flow_rate``.
+        - The ``GenericMotor`` class considers the total_mass_flow_rate as the
+        same as the mass_flow_rate.
 
         It should be noted that, for hybrid motors, the oxidizer mass flow
         rate should not be greater than `total_mass_flow_rate`, otherwise the
@@ -1219,6 +1221,14 @@ def exhaust_velocity(self):
         """
         return self.total_impulse / self.propellant_initial_mass
 
+    @funcify_method("Time (s)", "Mass Flow Rate (kg/s)")
+    def mass_flow_rate(self):
+        """Time derivative of propellant mass. Assumes constant exhaust
+        velocity. The formula used is the opposite of thrust divided by
+        exhaust velocity.
+        """
+        return -1 * self.thrust / self.exhaust_velocity
+
     @funcify_method("Time (s)", "center of mass (m)")
     def center_of_propellant_mass(self):
         """Estimates the propellant center of mass as fixed in the chamber

rocketpy/plots/environment_plots.py

@@ -121,14 +121,14 @@ def __wind_components(self, ax):
         ax.plot(
             [self.environment.wind_velocity_x(i) for i in self.grid],
             self.grid,
-            label="Wind U",
+            label="wind u",
         )
         ax.plot(
             [self.environment.wind_velocity_y(i) for i in self.grid],
             self.grid,
-            label="Wind V",
+            label="wind v",
         )
-        # ax.legend(loc="best").set_draggable(True)
+        ax.legend(loc="best")
         ax.set_ylabel("Height Above Sea Level (m)")
         ax.set_xlabel("Wind Speed (m/s)")
         ax.grid(True)
@@ -221,7 +221,6 @@ def atmospheric_model(self):
         # Create wind u and wind v subplot
         ax3 = plt.subplot(223)
         ax3 = self.__wind_components(ax3)
-        # ax3.legend(loc="best").set_draggable(True)
 
         # Create pressure and temperature subplot
         ax4 = plt.subplot(224)
@@ -255,7 +254,6 @@ def ensemble_member_comparison(self):
                 self.grid,
                 label=i,
             )
-        # ax5.legend(loc='best').set_draggable(True)
         ax5.set_ylabel("Height Above Sea Level (m)")
         ax5.set_xlabel("Wind Speed (m/s)")
         ax5.set_title("Wind U - Ensemble Members")
@@ -270,7 +268,6 @@ def ensemble_member_comparison(self):
                 self.grid,
                 label=i,
             )
-        # ax6.legend(loc='best').set_draggable(True)
         ax6.set_ylabel("Height Above Sea Level (m)")
         ax6.set_xlabel("Wind Speed (m/s)")
         ax6.set_title("Wind V - Ensemble Members")
@@ -283,7 +280,6 @@ def ensemble_member_comparison(self):
             ax7.plot(
                 [self.environment.wind_speed(i) for i in self.grid], self.grid, label=i
             )
-        # ax7.legend(loc='best').set_draggable(True)
         ax7.set_ylabel("Height Above Sea Level (m)")
         ax7.set_xlabel("Wind Speed (m/s)")
         ax7.set_title("Wind Speed Magnitude - Ensemble Members")
@@ -298,7 +294,6 @@ def ensemble_member_comparison(self):
                 self.grid,
                 label=i,
             )
-        # ax8.legend(loc='best').set_draggable(True)
         ax8.set_ylabel("Height Above Sea Level (m)")
         ax8.set_xlabel("Degrees True (°)")
         ax8.set_title("Wind Direction - Ensemble Members")
@@ -311,7 +306,6 @@ def ensemble_member_comparison(self):
             ax9.plot(
                 [self.environment.pressure(i) for i in self.grid], self.grid, label=i
             )
-        # ax9.legend(loc='best').set_draggable(True)
         ax9.set_ylabel("Height Above Sea Level (m)")
         ax9.set_xlabel("Pressure (P)")
         ax9.set_title("Pressure - Ensemble Members")
@@ -324,7 +318,6 @@ def ensemble_member_comparison(self):
             ax10.plot(
                 [self.environment.temperature(i) for i in self.grid], self.grid, label=i
             )
-        # ax10.legend(loc='best').set_draggable(True)
         ax10.set_ylabel("Height Above Sea Level (m)")
         ax10.set_xlabel("Temperature (K)")
         ax10.set_title("Temperature - Ensemble Members")