Add Hooks for Angle Coordinates to Roll (#119)

* Added new hooks to roll and roll_pass as well as corresponding hookimpls.

* updated implementation of surface_velocity

* updated implementation of surface_velocity.
Again!

* upd version number

* deleted unnecessary lines

* updated surface velocity hook

* updated velocity hook

Author: ChRen95

pyroll/core/__init__.py

@@ -12,7 +12,7 @@
 from .disk_elements import DiskElementUnit
 from .config import Config, config
 
-VERSION = "2.1.1"
+VERSION = "2.1.2"
 
 root_hooks.update(
     {

pyroll/core/roll/roll.py

@@ -99,6 +99,9 @@ class Roll(HookHost):
     thermal_diffusivity = Hook[float]()
     """Mean thermal diffusivity of the roll material."""
 
+    neutral_angle = Hook[float]()
+    """Angle at the roll surface where the shear stress is zero."""
+
     neutral_point = Hook[float]()
     """Point at the roll surface where the shear stress is zero."""
 

pyroll/core/roll_pass/hookimpls/roll.py

@@ -33,11 +33,22 @@ def center(self: RollPass.Roll):
     return np.array([0, self.roll_pass.gap / 2 + self.nominal_radius])
 
 
+@RollPass.Roll.neutral_angle
+def neutral_angle(self: RollPass.Roll):
+    if self.has_value("neutral_point"):
+        return -np.arcsin(self.neutral_point / self.working_radius)
+
+
+@RollPass.Roll.neutral_point
+def neutral_point(self: RollPass.Roll):
+    if self.has_set_or_cached("neutral_angle"):
+        return -np.sin(self.neutral_angle) * self.working_radius
+
+
 @RollPass.Roll.surface_velocity
 def surface_velocity(self: RollPass.Roll):
     if self.roll_pass.has_set("velocity"):
-        if self.has_value("neutral_point"):
-            alpha = np.arcsin(-self.neutral_point / self.working_radius)
+        if self.has_value("neutral_angle"):
+            return self.roll_pass.velocity / np.cos(self.neutral_angle)
         else:
-            alpha = 0
-        return self.roll_pass.velocity / np.cos(alpha)
+            return self.roll_pass.velocity / np.cos(0)

pyroll/core/roll_pass/hookimpls/roll_pass.py

@@ -139,11 +139,10 @@ def contact_area3(self: ThreeRollPass):
 
 @RollPass.velocity
 def velocity(self: RollPass):
-    if self.roll.has_value("neutral_point"):
-        alpha = np.arcsin(-self.roll.neutral_point / self.roll.working_radius)
+    if self.roll.has_value("neutral_angle"):
+        return self.roll.surface_velocity * np.cos(self.roll.neutral_angle)
     else:
-        alpha = 0
-    return self.roll.surface_velocity * np.cos(alpha)
+        return self.roll.surface_velocity * np.cos(0)
 
 
 @RollPass.duration
@@ -222,3 +221,8 @@ def roll_power(self: RollPass):
 @ThreeRollPass.power
 def roll_power_3(self: ThreeRollPass):
     return 3 * self.roll.roll_power
+
+
+@RollPass.entry_angle
+def entry_angle(self: RollPass):
+    return -np.arcsin(self.roll.contact_length / self.roll.working_radius)

pyroll/core/roll_pass/roll_pass.py

@@ -60,6 +60,9 @@ class RollPass(DiskElementUnit, DeformationUnit):
     roll_force = Hook[float]()
     """Vertical roll force."""
 
+    entry_angle = Hook[float]()
+    """Angle at which the material enters the roll gap."""
+
     front_tension = Hook[float]()
     """Front tension acting on the current roll pass."""