Material: update fluid material and correct 2 value errors

src/Mod/Material/CMakeLists.txt

@@ -45,7 +45,7 @@ SET (FluidMaterial_Files
     FluidMaterial/None.FCMat
     FluidMaterial/Air.FCMat
     FluidMaterial/Water.FCMat
-    FluidMaterial/Readme.txt
+    FluidMaterial/Readme.md
 )
 SOURCE_GROUP("MatLib" FILES ${FluidMaterial_Files})
 

src/Mod/Material/FluidMaterial/Air.FCMat

@@ -1,17 +1,22 @@
-[FCMat]
+[General]
 Name = Air
 Description = Standard air properties at 20 Degrees Celsius and 1 atm
 MolarMass = 28.965
+Father = Gas
 
+[Fluidic]
 Density = 1.20 kg/m^3
 DynamicViscosity = 1.80e-5 kg/m/s
 KinematicViscosity = 1.511e-5 m^2/s
-
-VolumetricThermalExpansionCoefficient = 3.43e-3 m/m/K
+; PrandtlNumber is a nondimension number for CFD simulation
 PrandtlNumber = 0.7
 
+[Thermal]
 SpecificHeat = 1.005 J/kg/K
 ThermalConductivity = 0.0257 W/m/K
+; volumetric expansion coeff of ideal gas depends on temperature and pressure
+VolumetricThermalExpansionCoefficient = 3.43e-3 m/m/K
 
+[Electrical]
 RelativePermittivity = 1.00059
 ; at 18°C and 50Hz

src/Mod/Material/FluidMaterial/None.FCMat

@@ -1,12 +1,16 @@
-[FCdMat]
+; None means nothing, as the starting point of making a new fluid material
+
+[General]
 Name = None
-Description = None
+Description = "None"
 
+[Fluidic]
 Density = 0 kg/m^3
 DynamicViscosity = 0 kg/m/s
 KinematicViscosity = 0 m^2/s
-VolumetricThermalExpansionCoefficient = 0 m/m/K
 
+[Thermal]
 SpecificHeat = 0 J/kg/K
 ThermalConductivity = 0 W/m/K
 ThermalExpansionCoefficient = 0 um/m/K
+VolumetricThermalExpansionCoefficient = 0 m/m/K

src/Mod/Material/FluidMaterial/Readme.md

@@ -0,0 +1,34 @@
+# FreeCAD fluid material library
+
+ It's intended to gather the most common fluid properties, water, air, which are useful for other modules and workbenches.
+
+## User defined material
+
+To prevent the database from becomming inefficiently large it is only limited to commonly used variables at 20 degrees Celcius at 1 atm.  
+
+Users can defined new material, either in Fem material card editor, or directly generate textual material file, * .FCMat, see example in this folder.   
+
+To enable new material, go to FreeCAD menu "Edit->Preference..." Cfd preference page (select on the left panel) and switch to materail tab on the right.  Browse to your material folder, and save/apply this preference, new material will b
+
+Material with same name as FreeCAD material has higher priority, so user defined` Water` material will not appear in Fem material task panel's dropbox list, just give it a different name!
+
+### Edit material value
+
+Please verify the fluid material properties before use. It aims to serve as a quick reference and does not aim to be an extended look up table.
+
+
+
+## Add new material to Material module
+
+1. follow examples in material folders to create new material file
+2.  stick to the meta data definition in `src/Mod/Material/Templatematerial.yml` for property name
+3. add the file name into the `src/Mod/Material/CMakeLists.txt` , so the new files can be installed to the properly place during compiling and installation. 
+
+## Change log
+
+CfdOF module authored 5 material types, values are taken from FM White (2011) Fluid Mechanics. 
+
+
+
+Currently, 3 (Water, Air, None) are merged into Fem module and maintained by Cfd module author, Qingfeng Xia 
+

src/Mod/Material/FluidMaterial/Water.FCMat

@@ -1,16 +1,24 @@
-[FCdMat]
+;  see meta data definition in the file: src/Mod/Material/Templatematerial.yml
+[General]
 Name = Water
 Description = Standard distilled water properties at 20 Degrees Celsius and 1 atm
 MolarMass = 18
+Father = Gas
+ReferenceSource = ''
 
+[Fluidic]
 Density = 998 kg/m^3
-DynamicViscosity = 1.003e-3 kg/m/s 
-KinematicViscosity = 1.005 m^2/s
+DynamicViscosity = 1.003e-3 kg/m/s
+KinematicViscosity = 1.005e-6 m^2/s
+; PrandtlNumber is a nondimension number for CFD simulation
+PrandtlNumber = 7.56
 
-VolumetricThermalExpansionCoefficient = 2.07e-4 m/m/K
-
-SpecificHeat = 4.182 J/kg/K
+[Thermal]
+SpecificHeat = 4182 J/kg/K
 ThermalConductivity = 0.591 W/m/K
+; https://en.wikipedia.org/wiki/Water
+VolumetricThermalExpansionCoefficient = 2.07e-4 m/m/K
 
+[Electrical]
 RelativePermittivity = 80.0
 ; at 20°C and 50Hz