Head loss due to friction in a pipe using Moody Diagram and the Darcy–Weisbach equation - YouTube
Moody Diagram
Friction Factor Calculator - Moody Equation
Inside the System: Hey Autodesk! Revit's definition of Relative Roughness is upside down!
head loss and relative roughness or roughness average matter duct pipe
Pipe Flow-Friction Factor Calculator Excel SpreadsheetLow Cost Easy to Use Spreadsheets for Engineering Calculations Available at Engineering Excel Spreadsheets