Separation constraint using surface vector projection

adflow/pyADflow.py

@@ -5766,8 +5766,11 @@ def _getDefaultOptions():
             "verifySpatial": [bool, True],
             "verifyExtra": [bool, True],
             # Function parmeters
+            "computeSepSensorKs": [bool, False],
+            "sepSensorMaxRho": [float, 1000.0],
             "sepSensorOffset": [float, 0.0],
             "sepSensorSharpness": [float, 10.0],
+            "sepAngleDeviation": [float, 90.0],
             "cavSensorOffset": [float, 0.0],
             "cavSensorSharpness": [float, 10.0],
             "cavExponent": [int, 0],
@@ -6181,8 +6184,11 @@ def _getOptionMap(self):
             "verifyextra": ["adjoint", "verifyextra"],
             "usematrixfreedrdw": ["adjoint", "usematrixfreedrdw"],
             # Parameters for functions
+            "computesepsensorks": ["cost", "computesepsensorks"],
+            "sepsensormaxrho": ["physics", "sepsenmaxrho"],
             "sepsensoroffset": ["cost", "sepsensoroffset"],
             "sepsensorsharpness": ["cost", "sepsensorsharpness"],
+            "sepangledeviation": ["cost", "sepangledeviation"],
             "cavsensoroffset": ["cost", "cavsensoroffset"],
             "cavsensorsharpness": ["cost", "cavsensorsharpness"],
             "cavexponent": ["cost", "cavexponent"],
@@ -6326,6 +6332,7 @@ def _getObjectivesAndDVs(self):
             "clqdot": self.adflow.constants.costfuncclqdot,
             "cbend": self.adflow.constants.costfuncbendingcoef,
             "sepsensor": self.adflow.constants.costfuncsepsensor,
+            "sepsensorks": self.adflow.constants.costfuncsepsensorks,
             "sepsensoravgx": self.adflow.constants.costfuncsepsensoravgx,
             "sepsensoravgy": self.adflow.constants.costfuncsepsensoravgy,
             "sepsensoravgz": self.adflow.constants.costfuncsepsensoravgz,

doc/costFunctions.yaml

@@ -307,6 +307,15 @@ sepsensor:
     The separation values for the given surface is provided by this cost function.
     See :cite:t:`Kenway2017b` for more details.
 
+sepsensorks:
+  desc: >
+    The separation sensor value based on the KS aggregation for the given surface is provided by this cost function.
+    We first compute the deviation of the local velocity from the projected freestream on the desired surface. 
+    Then, we use a trigonometric function to compute the sensor by providing an allowable flow deviation angle from this projected vector. 
+    As a result, the sensor provides values form ``1`` to ``-.inf``. 
+    Any values that are greater than 0 are out of the alowable flow deviation.
+    Thus, to constraint the separation, we use KS aggregation to find the maximum value in the sensor and can constraint it to be less than or equal to ``0``.
+
 sepsensoravgx:
   desc: >
     The separation sensor average in x direction.

doc/options.yaml

@@ -1527,16 +1527,38 @@ verifyExtra:
     This option is for debugging the adjoint only.
     It is used to verify dIda.
 
+sepSensorMaxRho:
+  desc: >
+    The rho parameter used for the KS aggregation used for computing maximum separation sensor value in ``sepSensorKs`` cost function.
+    KS aggregation is used to compute the differentiable max separation sensor within the given family group.
+    A higher rho value will approach the actual max separation sensor value more accurately, at the cost of a more nonlinear function.
+
 sepSensorOffset:
   desc: >
-    The offset value used for the separation sensor.
+    The offset value used for the separation sensor in ``sepSensor`` cost function.
     See "Buffet-Onset Constraint Formulation for Aerodynamic Shape Optimization" (Kenway2017b) for more details.
 
 sepSensorSharpness:
   desc: >
-    The sharpness parameter for the separation sensor.
+    The sharpness parameter for the separation sensor in ``sepSensor`` cost function.
     See "Buffet-Onset Constraint Formulation for Aerodynamic Shape Optimization" (Kenway2017b) for more details.
 
+sepAngleDeviation:
+  desc: >
+    This option is for KS based separation sensor, ``sepSensorKs`` cost function.
+    This angle is used to compute the allowable flow deviation region with respect to the freestream projected direction on the desired surface.
+    For example, on a wing, the streamlines on the upper surface flows inboard direction. 
+    And in some regions, it goes in the outboard directions.
+    Therefore, we provide an allowable flow deviation from the projected freestream on the surface to compute the sensor.
+    For instance, when the angle is ``90`` degrees, this approximately closes to the verge of separation.
+    This angle (in degrees) is for 3D cases only.
+    For airfoils, by default, this is ``0``.
+
+computeSepSensorKs:
+  desc: >
+    Whether or not to compute KS based separation related cost functions, which is ``sepSensorKs`` cost function.
+    If this option is not set to ``True``, the code will return zero for this cost function.
+
 computeCavitation:
   desc: >
     Whether or not to compute cavitation related cost functions, which are `cavitation` and `cpMin`.

src/adjoint/adjointUtils.F90

@@ -2087,6 +2087,10 @@ subroutine setDiffSizes
         ISIZE1OFDrfDrfbcdata_sepSensor = 0
         ISIZE2OFDrfDrfbcdata_sepSensor = 0
 
+        ! sepSensorKs
+        ISIZE1OFDrfDrfbcdata_sepSensorKs = 0
+        ISIZE2OFDrfDrfbcdata_sepSensorKs = 0
+
         ! Cavitation
         ISIZE1OFDrfDrfbcdata_Cavitation = 0
         ISIZE2OFDrfDrfbcdata_Cavitation = 0