code: def dean_number(PlantFlow, IDTube, RadiusCoil, Temp):
      
      return (reynolds_rapid_mix(PlantFlow, IDTube, Temp)
              * (IDTube / (2 * RadiusCoil))**(1/2)
              )
docs: Return the Dean Number.
  
      The Dean Number is a dimensionless parameter that is the unfortunate
      combination of Reynolds and tube curvature. It would have been better
      to keep the Reynolds number and define a simple dimensionless geometric
      parameter.