update friction factor

Author: Brad Carman

src/Hydraulic/IsothermalCompressible/utils.jl

@@ -92,11 +92,12 @@ Reference: Introduction to Fluid Mechanics, Fox & McDonald, 5th Edition, equatio
 """
 function friction_factor(dm, area, d_h, density, viscosity, shape_factor)
     u = abs(dm) / (density * area)
-    Re = maximum([density * u * d_h / viscosity, 1])
-
+    
+    Re = density * u * d_h / viscosity
     f_laminar = shape_factor / Re
+    
+    Re = maximum([Re, 1])
     f_turbulent = (shape_factor / 64) * (0.79 * log(Re) - 1.64)^(-2)
-    # f_turbulent = (shape_factor / 64) * regPow(0.79 * log(Re) - 1.64, -2)
 
     f = transition(2000, 3000, f_laminar, f_turbulent, Re)