Change the default setting for RegFunctionPart to 2 in OLAF

docs/source/user/aerodyn-olaf/ExampleFiles/ExampleFile--OLAF.dat

@@ -23,8 +23,8 @@ default FWShedVorticity    - Include shed vorticity in the far wake {default: fa
 default DiffusionMethod    - Diffusion method to account for viscous effects {0: None, 1: Core Spreading, "default": 0}         
 2       RegDeterMethod     - Method to determine the regularization parameters {0: Constant, 1: Optimized, 2: Chord-scaled, 3: dr-scaled, default: 0 }          
 default RegFunction        - Segment regularization function {0: None, 1: Rankine, 2: LambOseen, 3: Vatistas, 4: Denominator, "default": 3} (switch)
-default RegFunctionPart    - Particle regularization function {0: None, 1: Exponential, 2: Compact, "default": 1} [only if VelocityMethod=2,3] (switch)
-default WakeRegMethod      - Wake regularization method {1: Constant, 2: Stretching, 3: Age, default: 1} (switch)
+default RegFunctionPart    - Particle regularization function {0: None, 1: Exponential, 2: Compact, "default": 2} [only if VelocityMethod=2,3] (switch)
+default WakeRegMethod      - Wake regularization method {1: Constant, 2: Stretching, 3: Age, default: 3} (switch)
 0.25    WakeRegFactor      - Wake regularization factor (m or -)
 0.25    WingRegFactor      - Wing regularization factor (m or -)
 1000    CoreSpreadEddyVisc - Eddy viscosity in core spreading methods, typical values 1-1000 

docs/source/user/aerodyn-olaf/InputFiles.rst

@@ -199,7 +199,7 @@ faster than the exponential option depending on the case (wake size, particle
 count, and regularization parameter).
 The compact-support kernel is also purely polynomial and avoids evaluating a
 transcendental (exponential) function, which can further reduce cost.
-The default option is *[1]*.
+The default option is *[2]*.
 
 **WakeRegMethod** [switch] specifies the method of determining viscous core
 radius (i.e., the regularization parameter). There are three options: 1)

docs/source/user/aerodyn-olaf/OLAFTheory.rst

@@ -625,7 +625,7 @@ point-vortex kernel is recovered.
 Exponential
 ^^^^^^^^^^^
 
-If the exponential method is used (**RegFunctionPart=[1]**, the default), the
+If the exponential method is used (**RegFunctionPart=[1]**), the
 regularization factor is
 
 .. math::
@@ -638,7 +638,7 @@ negligible and :math:`g` is set to :math:`1`.
 Compact support
 ^^^^^^^^^^^^^^^^
 
-If the compact-support method is used (**RegFunctionPart=[2]**), the kernel is
+If the compact-support method is used (**RegFunctionPart=[2]**, the default), the kernel is
 *exactly* singular (:math:`g=1`) beyond a finite support radius
 :math:`r_c'=1.6\,r_c`, and inside the support it is given by a polynomial
 mollifier

docs/source/user/api_change.rst

@@ -16,7 +16,7 @@ Under-relaxation is introduced for the tight-coupling iterative solver to improv
 
 The generalized support-structure (GS) influence model was added to AeroDyn. This introduces three new switches (``GSPotent``, ``GSShadow``, ``GSAero``) after ``TwrAero`` in the AeroDyn primary input file, and two new sections (``General support structure joints`` and ``General support structure members``) after the ``Tower Influence and Aerodynamics`` section. The two new sections are required even when the GS model is disabled (set ``NumGSJoints`` and ``NumGSMembers`` to 0, keeping the table header lines).
 
-OLAF now selects the regularization function for the vortex particles separately from the vortex segments. The new ``RegFunctionPart`` input on line 26 of the OLAF input file controls the particle kernel, and ``RegFunction`` now applies only to the segments. Previously the particle kernel was inferred from ``RegFunction``: any regularized value gave an exponential particle kernel, while ``RegFunction=0`` gave an unregularized one. The default ``RegFunctionPart=1`` reproduces the exponential kernel, so results are unchanged for decks with ``RegFunction`` greater than 0. Decks with ``RegFunction=0`` will change: the particles are now regularized with the exponential kernel unless ``RegFunctionPart=0`` is also set. Setting ``RegFunctionPart=0`` restores an unregularized particle kernel, but with ``VelocityMethod=2`` the results will still differ from previous versions because the particle-tree far-field cutoff is no longer padded by the particle core radius when the particle kernel is unregularized.
+OLAF now selects the regularization function for the vortex particles separately from the vortex segments. The new ``RegFunctionPart`` input on line 26 of the OLAF input file controls the particle kernel, and ``RegFunction`` now applies only to the segments. Setting ``RegFunctionPart=1`` reproduces the exponential kernel previously used with ``RegFunction`` greater than 0. Setting ``RegFunctionPart=0`` restores an unregularized particle kernel previously used with ``RegFunction=0``. The newly added default compact particle regularization (``RegFunctionPart=2``) provides significant speed up compared to the exponential kernel (``RegFunctionPart=1``).
 
 ============================================= ======== ==================== ==========================================================================================================================================================================================================================================================================================================
 Added in OpenFAST `5.1.0`
@@ -38,7 +38,7 @@ AeroDyn                                       \*                            ====
 AeroDyn                                       \*       NumGSMembers         0   NumGSMembers - Number of general support members (-)
 AeroDyn                                       \*                            GSMemberID  GSMJointID1  GSMJointID2     GSMDia1       GSMDia2     GSMCd1        GSMCd2        GSMTI1       GSMTI2       GSMDiv
 AeroDyn                                       \*                            (-)            (-)          (-)           (m)           (m)          (-)           (-)          (-)          (-)           (m)
-OLAF                                          26       RegFunctionPart            2  RegFunctionPart - Particle regularization function {0: None, 1: Exponential, 2: Compact, "default": 1} [only if VelocityMethod=2,3] (switch)
+OLAF                                          26       RegFunctionPart      default  RegFunctionPart - Particle regularization function {0: None, 1: Exponential, 2: Compact, "default": 2} [only if VelocityMethod=2,3] (switch)
 ============================================= ======== ==================== ==========================================================================================================================================================================================================================================================================================================
 
 OpenFAST v4.2.x to OpenFAST  v5.0.0

modules/aerodyn/src/FVW_IO.f90

@@ -60,7 +60,7 @@ SUBROUTINE FVW_ReadInputFile( FileName, p, m, Inp, ErrStat, ErrMsg )
    CALL ReadVarWDefault(UnIn,FileName,Inp%DiffusionMethod    ,'DiffusionMethod'   ,'',idDiffusionNone , ErrStat2,ErrMsg2); if(Failed())return
    CALL ReadVarWDefault(UnIn,FileName,Inp%RegDeterMethod     ,'RegDeterMethod'    ,'',idRegDeterConstant, ErrStat2,ErrMsg2); if(Failed())return
    CALL ReadVarWDefault(UnIn,FileName,Inp%RegFunction        ,'RegFunction'       ,'',idRegVatistas   , ErrStat2,ErrMsg2); if(Failed())return
-   CALL ReadVarWDefault(UnIn,FileName,Inp%RegFunctionPart    ,'RegFunctionPart'   ,'',idRegExp        , ErrStat2,ErrMsg2); if(Failed())return
+   CALL ReadVarWDefault(UnIn,FileName,Inp%RegFunctionPart    ,'RegFunctionPart'   ,'',idRegCompact    , ErrStat2,ErrMsg2); if(Failed())return
    CALL ReadVarWDefault(UnIn,FileName,Inp%WakeRegMethod      ,'WakeRegMethod'     ,'',idRegAge        , ErrStat2,ErrMsg2); if(Failed())return
    CALL ReadVar        (UnIn,FileName,Inp%WakeRegParam       ,'WakeRegParam'      ,''                 , ErrStat2,ErrMsg2); if(Failed())return
    CALL ReadVar        (UnIn,FileName,Inp%WingRegParam       ,'WingRegParam'      ,''                 , ErrStat2,ErrMsg2); if(Failed())return

openfast_io/openfast_io/FAST_writer.py

@@ -1360,7 +1360,7 @@ def write_OLAF(self):
         f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['DiffusionMethod'], 'DiffusionMethod','- Diffusion method to account for viscous effects {0: None, 1: Core Spreading, "default": 0}\n'))
         f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['RegDeterMethod'], 'RegDeterMethod','- Method to determine the regularization parameters {0:  Manual, 1: Optimized, 2: Chord, 3: Span, default: 0 }\n'))
         f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['RegFunction'], 'RegFunction','- Segment regularization function {0: None, 1: Rankine, 2: LambOseen, 3: Vatistas, 4: Denominator, "default": 3} (switch)\n'))
-        f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['RegFunctionPart'], 'RegFunctionPart','- Particle regularization function {0: None, 1: Exponential, 2: Compact, "default": 1} [only if VelocityMethod=2,3] (switch)\n'))
+        f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['RegFunctionPart'], 'RegFunctionPart','- Particle regularization function {0: None, 1: Exponential, 2: Compact, "default": 2} [only if VelocityMethod=2,3] (switch)\n'))
         f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['WakeRegMethod'], 'WakeRegMethod','- Wake regularization method {1: Constant, 2: Stretching, 3: Age, default: 3} (switch)\n'))
         f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['WakeRegFactor'], 'WakeRegFactor','- Wake regularization factor (m)\n'))
         f.write('{:<22} {:<11} {:}'.format(self.fst_vt['AeroDyn']['OLAF']['WingRegFactor'], 'WingRegFactor','- Wing regularization factor (m)\n'))