code: def Re(L: float, v: float, nu: float) -> float:
      
  
      return v * L / nu
docs: Calculate the Reynolds number.
  
      :param L: [m] surface characteristic length.
      :param v: [m/s] fluid velocity relative to the object.
      :param nu: [m2/s] fluid kinematic viscosity.
  
      :returns: float