AnsweredAssumed Answered

Zero total pressure

Question asked by Simone Storace on Aug 25, 2014
Latest reply on Sep 19, 2014 by Jared Conway

Hello,

I'm trying to condensate steam along a duct.

I've read that FlowSimultiation allows only mass fraction of condensate not greater than 5%, so i've imposed boundary condition to not overcome this limit.

My BC are:

  • Inlet mass flow rate = 1.676 * 10^(-3) kg/s
  • Static pressure Outlet = 5 bar
  • T inlet = 425 K
  • Duct Lenght = 0.8 meters
  • Duct Diameter = 0.02 meters
  • Thermal flux = - 5 watt (surface surce)

The analysis have no problem to converge, but there is something i can't understand:

The values of total temperature and total pressure on outlet surface are zero.

The internal surface of the duct is equally divided in two part and the heat exchange takes place only in the second part; the first one is adiabatic.

The velocity and static pressure profile seem correct compared to the standard profile in a tube.

The next picture shows the results of a cutplot plotting total pressure.

 

Ptot.PNG

Is there something that I'm wrong?

Is there something in fluid-dynamic theory that i've forgot?

 

Thanks for the answers

Greetings

Simone

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