Say I have a pipe of length L and an inner diameter of ID. Inside is a heated rod of diameter OD that is uniformly heated with power P. I have water flowing through the pipe with mass flow rate G under pressure p. The specific enthalpy at the inlet is H. I want to calculate the vapor quality x at the inlet and outlet.

I believe the correct way to do this for the inlet is: $x_{in}=\frac{H-h_f}{h_{fg}}$

And for the outlet it would be something like: $x_{out}=x_{in}+\frac{P}{G\times h_{fg}}$

I mostly want to check that this makes sense.

  • $\begingroup$ Is the pressure approximately constant over the length of the pipe? $\endgroup$ – Chet Miller Aug 26 at 17:00
  • $\begingroup$ Yes, it is approximately constant. $\endgroup$ – twalker Aug 26 at 17:16
  • 1
    $\begingroup$ I confirm your result $\endgroup$ – Chet Miller Aug 26 at 18:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.