Error in the Hooper method for conical diffuser/expansion

[AllanBjerg]

Dear Caleb,

It is a great tool that you have developed!

I am currently working with the Hooper method for a conical diffuser/expansion from the fluids.fittings library. I think there is a small error for the case of Re_1 < 4000 and angle < 45°. It returns K = K_sharp while it should return K = K_sharp2.6sin(angle/2).

Code is stated below: elif method == 'Hooper': if Re is None: raise ValueError("Method Hooper requires Reynolds number") if Re < 4000.0: return 2.0*(1.0 - betabetabetabeta) # Not the same formula as Rennels if fd is None: fd = Clamond(Re=Re, eD=roughness/Di1) x = 1.0 - betabeta K = (1.0 + 0.8fd)xx if angle_rad > 0.25pi: return K return K2.6sin(0.5*angle_rad)

Best regards, Allan