Calculate buoyancy for an MHK turbine

docs/OtherSupporting/OpenFAST_Algorithms/OpenFAST_Algorithms.tex

@@ -215,6 +215,7 @@ \section{Input-Output Relationships}
                                       & \mathit{y\_SD},  \mathit{u\_SD\_tmp},  \\  
                                       & \mathit{y\_MAP}, \mathit{u\_MAP\_tmp}, \\ 
                                       & \mathit{y\_FEAM},\mathit{u\_FEAM\_tmp},\\
+                                      & \mathit{y\_AD},  \mathit{u\_AD\_tmp}\footnote{Only if AD buoyancy at of hub enabled.},  \\  
                                       & \mathit{y\_SrvD},\mathit{u\_SrvD\_tmp}\footnote{Only if using ServoDyn Structural control.} )    % SrvD%PtfmStC only
                      \end{aligned}$
 

docs/source/user/aerodyn-aeroacoustics/App-usage.rst

@@ -5,11 +5,12 @@ Using the Aeroacoustics Model in AeroDyn
 
 A live version of this documentation is available at
 https://openfast.readthedocs.io/. To run the aeroacoustics model, the
-flag **CompAA** needs to be set to **True** at line 13 of the AeroDyn15 main
+flag **CompAA** needs to be set to **True** at line 14 of the AeroDyn15 main
 input file in the inputs block **General Options**. When the flag is set to
 **True**, the following line must include the name of the file containing
 the inputs to the aeroacoustics model, which is discussed in
-:numref:`aa-sec-BLinputs`.
+:numref:`aa-sec-MainInput`. Currently, this module cannot be used with an MHK
+turbine.
 
 
 .. container::

docs/source/user/aerodyn-aeroacoustics/example/AD15.ipt

@@ -2,17 +2,18 @@
 IEA Wind Task 37 land-based reference wind turbine
 ====== General Options ===================================================
 False          Echo        - Echo the input to "<rootname>.AD.ech"? (flag)
-"default"      DT_AA       - Time interval for aerodynamic calculations {or "default"} (s)
+"default"      DTAero      - Time interval for aerodynamic calculations {or "default"} (s)
 1              WakeMod     - Type of wake/induction model (switch) {0=none, 1=BEMT}
 2              AFAeroMod   - Type of blade airfoil aerodynamics model (switch
 0              TwrPotent   - Type of tower influence on wind around the tower (switch)
 0              TwrShadow   - Type of tower influence on wind based on downstream tower shadow (switch) {0=none, 1=Powles model, 2=Eames model}
 False          TwrAero     - Calculate tower aerodynamic loads? (flag)
 False          FrozenWake  - Assume frozen wake during linearization? (flag
 False          CavitCheck  - Perform cavitation check? (flag)
+False          Buoyancy    - Include buoyancy effects? (flag)
 True           CompAA      - Flag to compute AeroAcoustics calculation
 "AeroAcousticsInput.dat"   AA_InputFile
 ====== Environmental Conditions ==========================================
-1.225.         AirDens     - Air density (kg/m^3)
+"default"      AirDens     - Air density (kg/m^3)
 
 File continues...

docs/source/user/aerodyn/ADNodalOutputs.rst

@@ -10,7 +10,7 @@ for a complete list of possible output parameters.
 
 This section follows the `END` statement from normal Outputs section described
 above, and includes a separator description line followed by the following
-optinos.
+options.
 
 **BldNd_BladesOut** specifies the number of blades to output. Possible values
 are 0 through the number of blades AeroDyn is modeling. If the value is set to

docs/source/user/aerodyn/appendix.rst

@@ -27,7 +27,7 @@ outside of OpenFAST.
 3) AeroDyn Primary Input File 
 :download:`(primary input file example) <examples/ad_primary_example.dat>`: 
 
-The primary AeroDyn input file defines modeling options, environmental conditions (except freestream flow), airfoils, tower nodal discretization and properties, as well as output file specifications.
+The primary AeroDyn input file defines modeling options, environmental conditions (except freestream flow), airfoils, tower nodal discretization and properties, tower, hub, and nacelle buoyancy properties, as well as output file specifications.
 
 The file is organized into several functional sections.  Each section corresponds to an aspect of the aerodynamics model.  
 
@@ -44,14 +44,14 @@ The airfoil data input files themselves (one for each airfoil) include tables co
 5) Blade Data Input File
 :download:`(blade data input file example) <examples/ad_blade_example.dat>`: 
 
-The blade data input file contains the nodal discretization, geometry, twist, chord, and airfoil identifier for a blade.  Separate files are used for each blade, which permits modeling of aerodynamic imbalances.  
+The blade data input file contains the nodal discretization, geometry, twist, chord, airfoil identifier, and buoyancy properties for a blade.  Separate files are used for each blade, which permits modeling of aerodynamic imbalances.  
 
 .. _ad_output_channels:
 
 AeroDyn List of Output Channels
 -------------------------------
 
-This is a list of all possible output parameters for the AeroDyn module.  The names are grouped by meaning, but can be ordered in the OUTPUTS section of the AeroDyn input file as you see fit.  :math:`B \alpha N \beta`, refers to output node :math:`\beta` of blade :math:`\alpha`, where :math:`\alpha` is a number in the range [1,3] and :math:`\beta` is a number in the range [1,9], corresponding to entry :math:`\beta` in the :math:`\textit{BlOutNd}` list.  :math:`\textit{TwN}\beta` refers to output node :math:`\beta` of the tower and is in the range [1,9], corresponding to entry :math:`\beta` in the :math:`\textit{TwOutNd}` list.
+This is a list of output parameters for the AeroDyn module.  The names are grouped by meaning, but can be ordered in the OUTPUTS section of the AeroDyn input file as you see fit.  :math:`B \alpha N \beta`, refers to output node :math:`\beta` of blade :math:`\alpha`, where :math:`\alpha` is a number in the range [1,3] and :math:`\beta` is a number in the range [1,9], corresponding to entry :math:`\beta` in the :math:`\textit{BlOutNd}` list.  :math:`\textit{TwN}\beta` refers to output node :math:`\beta` of the tower and is in the range [1,9], corresponding to entry :math:`\beta` in the :math:`\textit{TwOutNd}` list. A comprehensive, up-to-date list of all possible output parameters is given in the Excel file :download:`OutListParameters.xlsx <../../../OtherSupporting/OutListParameters.xlsx>`.
 
 The local tower coordinate system is shown in :numref:`ad_tower_geom` and the local blade coordinate system is shown in :numref:`ad_blade_local_cs` below.  Figure :numref:`ad_blade_local_cs` also shows the direction of the local angles and force components.
 

docs/source/user/aerodyn/driver.rst

@@ -63,7 +63,7 @@ More details are provided below, where the different sections of the input file
 The input file starts with a header, the user can place a relevant description of the model on the second line.
 The input configuration section follows. 
 The user can toggle the flag `Echo` to write back the input file, as parsed by the driver, to disk.
-The `MHK` switch allows the user to specify whether or not the turbine is an MHK turbine. `MHK=0` denotes not an MHK turbine, `MHK=1` denotes a fixed MHK turbine, and `MHK=2` denotes a floating MHK turbine. Currently, only `MHK=0` can be specified, although users can still select a cavitation check.
+The `MHK` switch allows the user to specify whether or not the turbine is an MHK turbine. `MHK=0` denotes not an MHK turbine, `MHK=1` denotes a fixed MHK turbine, and `MHK=2` denotes a floating MHK turbine. Currently, only `MHK=0` or `MHK=1` can be specified.
 The driver supports three kinds of analyses, but not all turbine formats and inflow types are available for each analysis type: 
 
 - `AnalysisType=1`: Simulation of one or multiple rotors with basic (HAWT) or arbitrary geometries (HAWT/VAWT, quad-rotor, etc.), with basic or advanced wind inputs, and optional time-varying motion of the tower base, nacelle and individual pitch angles. Arbitrary motion or sinusoidal motion of the tower base are possible.
@@ -91,7 +91,7 @@ An example of header and input configuration is given below:
 
 **Environmental conditions**
 
-Environmental conditions are specified here and passed to AeroDyn. `FldDens` (equivalent to `AirDens` in the AeroDyn primary input file) specifies the fluid density and must be a value greater than zero; a typical value is around 1.225 kg/m\ :sup:`3` for air (wind turbines) and 1025 kg/m\ :sup:`3` for seawater (MHK turbines). `KinVisc` specifies the kinematic viscosity of the fluid (used in the Reynolds number calculation); a typical value is around 1.460E-5 m\ :sup:`2`/s for air (wind turbines) and 1.004E-6 m\ :sup:`2`/s for seawater (MHK turbines). `SpdSound` is the speed of sound in the fluid (used to calculate the Mach number within the unsteady airfoil aerodynamics calculations); a typical value is around 340.3 m/s for air. The next two parameters in this section are only used when `CavitCheck = TRUE` for MHK turbines. `Patm` is the atmospheric pressure above the free surface; typically around 101,325 Pa. `Pvap` is the vapor pressure of the fluid; for seawater this is typically around 2,000 Pa. `WtrDpth` is the water depth from the seabed to the mean sea level (MSL).
+Environmental conditions are specified here and passed to AeroDyn. `FldDens` (equivalent to `AirDens` in the AeroDyn primary input file) specifies the fluid density and must be a value greater than zero; a typical value is around 1.225 kg/m\ :sup:`3` for air (wind turbines) and 1025 kg/m\ :sup:`3` for seawater (MHK turbines). `KinVisc` specifies the kinematic viscosity of the fluid (used in the Reynolds number calculation); a typical value is around 1.460E-5 m\ :sup:`2`/s for air (wind turbines) and 1.004E-6 m\ :sup:`2`/s for seawater (MHK turbines). `SpdSound` is the speed of sound in the fluid (used to calculate the Mach number within the unsteady airfoil aerodynamics calculations); a typical value is around 340.3 m/s for air (wind turbines) and 1500 m/s for seawater (MHK turbines). The next two parameters in this section are only used when `CavitCheck = TRUE` for MHK turbines. `Patm` is the atmospheric pressure above the free surface; typically around 101,325 Pa. `Pvap` is the vapor pressure of the fluid; for seawater this is typically around 2,000 Pa. `WtrDpth` is the water depth from the seabed to the mean sea level (MSL).
 
 **Inflow data**
 
@@ -349,7 +349,7 @@ No changes are required to the AeroDyn input files when one turbine is used.
 To minimize the impact of the multiple-turbines implementation, the driver currently uses only one AeroDyn input file for all turbines. 
 This means that the AeroDyn options are currently the same for all rotors.
 
-The definition of the blade files and tower inputs needs to be adapted when more than three blades are used and more than one turbine is used.
+The definition of the blade files and the tower, hub, and nacelle inputs needs to be adapted when more than three blades are used and more than one turbine is used.
 
 **Blade files**
 
@@ -371,6 +371,29 @@ An example is given below for two turbines, the first one having 3 blades, the s
     "AD_Turbine2_blade2.dat" ADBlFile(5) - Name of file containing distributed aerodynamic properties for Blade #5 (-) 
 
 
+
+**Hub and nacelle inputs**
+
+The sections defining the hub and nacelle buoyancy parameters must also be reproduced for each turbine.
+
+An example is given below for two turbines:
+
+.. code::
+
+    ======  Hub Properties ============================================================================== [used only when Buoyancy=True]
+    7.0   VolHub             - Hub volume (m^3)
+    0.0   HubCenBx           - Hub center of buoyancy x direction offset (m)
+    ======  Hub Properties ============================================================================== [used only when Buoyancy=True]
+    5.0   VolHub             - Hub volume (m^3)
+    0.2   HubCenBx           - Hub center of buoyancy x direction offset (m)
+    ======  Nacelle Properties ========================================================================== [used only when Buoyancy=True]
+    32.0  VolNac             - Nacelle volume (m^3)
+    0.3, 0.0, 0.05 NacCenB   - Position of nacelle center of buoyancy from yaw bearing in nacelle coordinates (m)
+    ======  Nacelle Properties ========================================================================== [used only when Buoyancy=True]
+    30.0  VolNac             - Nacelle volume (m^3)
+    0.5, 0.1, 0.05 NacCenB   - Position of nacelle center of buoyancy from yaw bearing in nacelle coordinates (m)
+
+
 **Aerodynamic tower inputs**
 
 The entire tower input section of AeroDyn has to be reproduced for each turbine, including turbines that are set not to have a tower (`hasTower=False`).
@@ -382,21 +405,19 @@ An example is given below for two turbines:
 
 .. code::
 
-    ======  Turbine(1) Tower Influence and Aerodynamics ================================================ [used only when TwrPotent/=0, TwrShadow=True, or TwrAero=True]
-    2   NumTwrNds   - Number of tower nodes used in the analysis  (-) [used only when TwrPotent/=0, TwrShadow=True, or TwrAero=True]
-    TwrElev TwrDiam  TwrCd    TwrTI
-    (m)       (m)     (-)     (-)
-     0.0      2.0     1.0    0.1
-    10.0      1.0     1.0    0.1
-    ======  Turbine(2) Tower Influence and Aerodynamics ================================================ [used only when TwrPotent/=0, TwrShadow=True, or TwrAero=True]
-    3   NumTwrNds   - Number of tower nodes used in the analysis  (-) [used only when TwrPotent/=0, TwrShadow=True, or TwrAero=True]
-    TwrElev TwrDiam  TwrCd   TwrTI
-    (m)       (m)     (-)    (-)
-     0.0      4.0     1.0    0.1
-    15.0      3.0     1.0    0.1
-    30.0      2.0     1.0    0.1
-
-
+    ======  Turbine(1) Tower Influence and Aerodynamics ================================================ [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
+    2   NumTwrNds   - Number of tower nodes used in the analysis  (-) [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
+    TwrElev TwrDiam  TwrCd    TwrTI   TwrCb
+    (m)       (m)     (-)     (-)     (-)
+     0.0      2.0     1.0    0.1      0.0
+    10.0      1.0     1.0    0.1      0.0
+    ======  Turbine(2) Tower Influence and Aerodynamics ================================================ [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
+    3   NumTwrNds   - Number of tower nodes used in the analysis  (-) [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
+    TwrElev TwrDiam  TwrCd   TwrTI   TwrCb
+    (m)       (m)     (-)    (-)     (-)
+     0.0      4.0     1.0    0.1     0.0
+    15.0      3.0     1.0    0.1     0.0
+    30.0      2.0     1.0    0.1     0.0
 
 
 .. _ad_inputfiles_examples:
@@ -425,10 +446,18 @@ An example of an AeroDyn driver for a basic inflow, basic HAWT, and combined cas
     Three bladed wind turbine, using basic geometry input
     ----- Input Configuration ---------------------------------------------------------------
     False           Echo         - Echo input parameters to "<rootname>.ech"?
+            0       MHK          - MHK turbine type (switch) {0: not an MHK turbine, 1: fixed MHK turbine, 2: floating MHK turbine}
             3       AnalysisType - {1: multiple turbines, one simulation, 2: one turbine, one time-dependent simulation, 3: one turbine, combined cases}
            11.0     TMax         - Total run time [used only when AnalysisType/=3] (s)
             0.5     DT           - Simulation time step [used only when AnalysisType/=3] (s)
     "./AD.dat"      AeroFile - Name of the primary AeroDyn input file
+    ----- Environmental Conditions ----------------------------------------------------------
+    1.225000000000000e+00     FldDens      - Density of working fluid (kg/m^3)
+    1.477551020408163e-05     KinVisc      - Kinematic viscosity of working fluid (m^2/s)
+    3.350000000000000e+02     SpdSound     - Speed of sound in working fluid (m/s)
+    1.035000000000000e+05     Patm         - Atmospheric pressure (Pa) [used only for an MHK turbine cavitation check]
+    1.700000000000000e+03     Pvap         - Vapour pressure of working fluid (Pa) [used only for an MHK turbine cavitation check]
+                        0     WtrDpth      - Water depth (m)
     ----- Inflow Data -----------------------------------------------------------------------
               0      CompInflow  - Compute inflow wind velocities (switch) {0=Steady Wind; 1=InflowWind}
     "unused"         InflowFile  - Name of the InflowWind input file [used only when CompInflow=1]

docs/source/user/aerodyn/examples/NodalOutputs.txt

@@ -54,5 +54,11 @@ END of input file (the word "END" must appear in the first 3 columns of this las
 "Uin"       - Axial induced velocity in rotating hub coordinates. Axial aligned with hub axis.     rotor plane polar hub rotating coordinates
 "Uit"       - Tangential induced velocity in rotating hub coordinates. Tangential to the rotation plane. Perpendicular to blade aziumth.     rotor plane polar hub rotating coordinates
 "Uir"       - Radial induced velocity in rotating hub coordinates. Radial outwards in rotation plane. Aligned with blade azimuth.     rotor plane polar hub rotating coordinates
+"Fbn"       - Buoyant force normal to chord per unit length at each node
+"Fbt"       - Buoyant force tangential to chord per unit length at each node
+"Fbs"       - Buoyant spanwise force per unit length at each node
+"Mbn"       - Buoyant moment normal to chord per unit length at each node
+"Mbt"       - Buoyant moment tangential to chord per unit length at each node
+"Mbs"       - Buoyant spanwise moment per unit length at each node
 END of input file (the word "END" must appear in the first 3 columns of this last OutList line)
 ---------------------------------------------------------------------------------------